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Analysis of phenolic acids and flavonoids in honey
Abstract
Honey is rich in phenolic acids and flavonoids, which exhibit a wide range of biological effects and act as natural antioxidants. The analysis of polyphenols has been regarded as a very promising way of studying floral and geographical origins of honeys. This review surveys recent literature on determination of these active compounds in honey. The analytical procedure to determine individual phenolic compounds involves their extraction from the sample matrix, analytical separation and quantification. We pay particular attention to sample pre-treatment and separation techniques (e.g., high-performance liquid chromatography and electrophoresis).
... They are represented by flavonoids and phenolic acids. The content of individual flavonoids and phenolic acids depends on the plant source; they are derived from nectar, propolis, and pollen [19,20,[35][36][37][38][39]. ...
... Their distinguishing feature is a diphenylpropane skeleton (C6-C3-C6) with varying degrees of oxidation of the central pyran ring, while most types of flavonoids (except catechins and anthocyanidins) contain a flavone skeleton with a ketone group in position 4. Flavonoids differ in the number and type of substituents (hydroxyl, glycosidic residues, and methoxy groups). The differences between the compounds in individual classes usually result from the different structures of only one terminal ring ( Figure 2) [19,39,49]. This affects the properties and biological activity of individual groups of flavonoids. ...
... idation of the central pyran ring, while most types of flavonoids (except catechins and anthocyanidins) contain a flavone skeleton with a ketone group in position 4. Flavonoids differ in the number and type of substituents (hydroxyl, glycosidic residues, and methoxy groups). The differences between the compounds in individual classes usually result from the different structures of only one terminal ring ( Figure 2) [19,39,49]. This affects the properties and biological activity of individual groups of flavonoids. ...
Honey is one of the most valuable components of the human diet. It is considered to be a functional food with health-promoting properties. Honey has bactericidal and bacteriostatic effects; is used to treat wounds and ulcers; relieves stress; supports the treatment of diseases of the digestive and respiratory systems; improves kidney function; and aids in convalescence. The healing and prophylactic effects of honey are closely related to its chemical composition. According to the literature, honey contains over 300 substances belonging to various groups of chemical compounds, some with antioxidant activity, including vitamins and phenolic compounds, mainly flavonoids and phenolic acids. This article provides insight into honey’s chemical composition and its pro-health activities. The antioxidant properties of honey were prioritized.
... The purified samples were subjected to HPLC on a Breeze 2 chromatography system fitted with a Sunfire C18 3.5 µm, 4.6 × 100 mm column and a Sunfire C18 3.5 µm, 4.6 × 20 mm guard column (Waters Limited). The samples or standards (2-5 µL) were injected onto the column and the mobile phase applied at 1 mL/min: the mobile phase was composed of a gradient between Buffer A (5% acetic acid in water) and Buffer B (5% acetic acid in acetonitrile) which was set to change from 100% Buffer A to 50% Buffer A: 50% Buffer B after 40 min, to 100% Buffer B from 40 to 50 min, and then to 100% Buffer A from 50 to 60 min) [31][32][33]. The absorbance of the eluent was measured at 280 nm and 320 nm and at 370 nm and 425 nm in two separate runs. ...
... YSH contains sugar and phenolic components consistent with the composition of many other types of honey, as reported in the literature [12,18,32,33]. We analyzed four separate honey samples: one sample of a commercial clover polyfloral honey and three samples of YSH obtained from different commercial suppliers. ...
... While several of the peaks were shared among all four honey samples, there were several which appeared to be differentially expressed. Ten different standard components, known to be present in previously studied honey samples, were used to identify peaks in the samples which were present at different levels [32]. The polyfloral honey was distinct from the three YSH samples. ...
Honey has become popular as a potential treatment for several ailments, including cancer. Honeys from different parts of the world have been shown to have different anti-proliferative, immune-modulatory, and anti-inflammatory actions. Yemeni Sidr honey (YSH) is world-renowned for its anti-inflammatory activity and has been suggested to have anti-cancer activity, although empirical evidence is lacking. We tested three YSH samples by HPLC to show they contained similar sugars and an overlapping group of phenolic and flavonoid components, as described previously. YSH’s apoptotic and anti-proliferative activities were measured in in vitro models of cancer growth. The treatment of breast cancer cell lines (MDA-MB-231 and MCF-7), a cervical cancer cell line (HeLa), and mouse melanoma cells (B16-BL6) with 1% (w/v) YSH in media for 48–72 h almost completely inhibited cell proliferation and promoted cell apoptosis. In contrast, a non-malignant HBL-100 cell line was more resistant to treatment with YSH. This suggests that YSH may be a good candidate as an anti-cancer treatment, which requires further study.
... When using extraction methods, the selectivity required for its quantification has been achieved by obtaining an extract enriched in sample analytes free of interfering matrix components. For honey samples, several authors regularly use liquid-liquid extraction technique with solvents such as ethyl acetate [11,12], ethanol [13] or methanol [14], depending on phenolic family to be separated. To achieve a better separation of the phases, in some cases they are assisted by centrifugation [13]. ...
... To achieve a better separation of the phases, in some cases they are assisted by centrifugation [13]. In addition, microwave-assisted extraction and ultrasound-assisted extraction have been highlighted as an innovation green extraction technology [12]. The use of both methodologies greatly reduces extraction times and achieves an effective increase in flavonoids recovery. ...
... In addition, some flavonoids such as quercetin, apigenin, chrysin, hesperetin, and kaempferol were also reported. [13][14][15][16] These compounds are responsible of honey's color, sensory characteristics, and antioxidant effect. Furthermore, it has been reported that the phenolic profile is an important tool for honey characterization. ...
... Our results agree with those described in literature, which reported that the presence of phenolic acids and flavonoids are variable in honey samples collected in different geographical regions. [15,16,19] The extracts E2 (monofloral) and E7 (polyfloral), both originated from Minas Gerais state, showed distinctive amounts of phenolic acids and flavonoids on their chemical composition (Table 3). For example, E7 showed a higher concentration of rosmarinic acid when compared to E2 and caffeic acid, quercetin and kaempferol were just quantified on the last one. ...
This study aimed to evaluate the chemical composition and antioxidant activity of phenolic extracts from monofloral and polyfloral honey samples obtained from different Brazilian regions. The chemical composition (total content of phenolic compounds and flavonoids) of extracts were measured by using colorimetric assays and analyzed by high performance liquid chromatographic (HPLC‐DAD). The antioxidant activity was evaluated by chemical and biochemical assays (reducing power assay, 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH⋅) and 2,2‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic) acid (ABTS⋅⁺) scavenger assays. It was also investigated the ability of extracts in attenuate lipid peroxidation induced by Fe²⁺ in phospholipids. The obtained results clearly demonstrated that the botanical origin and geographical region of honey collection influenced the chemical composition and antioxidant activity of extracts. Furthermore, the samples were constituted by phenolic acids and flavonoids, which p‐coumaric acid was predominant among the compounds identified. All samples were able to scavenge free radicals and inhibit lipid peroxidation, and good correlations were obtained between the flavonoid content and honey color. In conclusion, the obtained extracts were constituted by antioxidant compounds, which reinforce the usage of honey in human diets, and demonstrated that the region of honey collection strong influenced in the chemical composition and, consequently, its biological effect.
... The analysis of secondary metabolite compounds was performed using thin layer chromatography (TLC) method. Each honey sample was extracted using a liquid-liquid partition method [20] . The procedure was started by placing 100 ml of honey into a separating funnel and then 100 ml of ethyl acetate was added into it. ...
... Considering that flavonoids and phenolic are two groups of secondary metabolites most commonly found in honey, Cheung et al. [32] underlines that flavonoids and phenolic can be used as botanical markers to identify flower sources and the geographical origin of honey. Nevertheless, Pyrzynska and Biesaga [20] argued that flavonoid and phenolic content of multifloral honey was not only influenced by the flower source and geographical location, but also by the climatic conditions of particular sites where honey was produced. Physicochemical studies on honey from different geographical origin revealed that secondary metabolites content in honey was affected by types of honey, location of beekeeping, and time of harvest [27] . ...
Honey produced by the giant honeybee (Apis dorsata binghami) is considered as highly nutritious natural product and has long been used as health supplement. This type of honey is collected traditionally by honey hunters using crude method from forest. This study aimed at determining the diversity of pollen and secondary metabolite compounds in honey samples produced by giant honeybee collected from four regencies in Central Sulawesi. Honey samples were collected from Donggala, Banggai, Morowali, and Parigi Moutong. Modified acetolysis method was used for preparing pollen microscopic slides, while TLC method was performed for the detection of secondary metabolite compounds. The results showed that honey samples varied in their pollen diversity, with the number of pollen types found in honey sample from Donggala was 33, Banggai was 36, Morowali was 30, and Parigi Moutong was 57. All honey samples contained five classes of secondary metabolite compounds namely alkaloid, phenolic, flavonoid, tannin, and terpenoid. From this melissopalynological research, it could be concluded that honey samples produced by giant honeybee from Central Sulawesi are of good quality based on their pollen diversity and the content of secondary metabolite compounds.
... According to our results, the acerola fruits presented high content of the studied bioactive compounds, suggesting that these fruits may be exploited by the food and pharmaceutical industries to take advantage of the functional properties. Studies [27][28][29] have shown that phenolics help in the prevention and control of pathologies, such as cardiovascular and renal diseases, cancer and type 2 diabetes, which is attributed to their ability to sequester free radicals, chelate metal cations and donate hydrogen atoms or electrons and thereby, reducing the oxidative effects caused by active oxygen species. ...
... 36,37 The human body does not produce vitamin C, so it must be acquired through dietary ingestion or supplementation, as it performs several functions such as collagen production and maintenance, wound healing, reduced susceptibility to infections, in addition to its antioxidant action. [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] Considering the antioxidant activity, the values found herein were higher than those shown by Xu et al. 31 using the ABTS method. The authors reported mean concentrations of 130 and 90 µmol trolox g -1 FW for green and ripe acerola, respectively. ...
The potential of four commercial clones of unripe acerola fruit was investigated regarding a source of nutraceuticals and functional foods for industrial use. The chemical profiling of the BRS 235-Apodi, BRS 236-Cereja, BRS 237-Roxinha, and BRS 238-Frutacor clones was determined by the ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS-MS) technique coupled to multivariate statistical analysis, which were then correlated to ABTS •+ radical capture (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and ferric reducing antioxidant power (FRAP) assays in order to measure the antioxidant capacity. A total of 24 bioactive compounds were identified, including high amounts of quercetin-O-hexoside, astilbin, and apigenin, which were correlated to three clones (BRS 235, BRS 237, and BRS 238). On the other hand, the BRS 236 clone presented high contents of ascorbic acid, iso-ascorbic acid, citric acid, procyanidin B trimer, rutin, phenolic compounds, and antioxidant activity. These compounds were additionally found to be strongly associated with the antioxidant capacity of unripe acerola fruits. Therefore, the present study revealed that BRS 236 is a promising clone as an antioxidant source to be used as a functional food or ingredient.
... The therapeutic potential of honey is largely attributed to its synergistic effects of its components, including polyphenols and other secondary plant compounds, enzymes, ascorbic acid, Maillard reaction products, carotenoid-like substances, organic acids, amino acids, and proteins [72][73][74]. Phenolic compounds, such as flavonoids and phenolic acids, are particularly important and are further classified based on their basic structures. They include simple phenols, phenolic acids, coumarins, isocoumarins, naphthoquinones, xanthones, stilbenes, anthraquinones, flavonoids, and lignins [75]. ...
Stingless bee honey (SBH) is an intriguing type of honey produced by various genera of stingless bees. SBH has traditionally been used for its reputed therapeutic properties; yet scientific exploration on this honey remained less widespread compared to other types. This review aims to report recent physiochemical and phytochemical properties of SBH across various species and geographical origins. This review also aims to delve into the therapeutic potential of SBH, with a specific focus on its antioxidant, antibacterial, anticancer, and antidiabetic properties. By examining various studies on the medicinal attributes of SBH, this paper offers compelling evidence of its efficacy in treating diverse conditions, such as infections, inflammation, and many more. Furthermore, the distinctive composition of SBH was explored in detail, shedding light on its contribution to its remarkable medicinal characteristics. Ultimately, this review underscores the promising therapeutic potential of SBH and advocates further research to comprehensively comprehend its medicinal properties and unlock its potential for various medical applications.
... Among these, phenolic compounds and flavonoids are particularly valuable, as they can disrupt microbial cell membranes, inhibit bacterial growth, and neutralize free radicals. Consequently, plant-derived products, including honey, which is rich in such bioactive compounds, have become promising candidates for treating infections and mitigating the impact of antimicrobial resistance (Pyrzynska & Biesaga, 2009). Honey contains over 200 natural compounds, with its composition influenced by factors such as plant species, harvest conditions, and the geo-climatic characteristics of the production regions (da Silva et al., 2016). ...
Honey is renowned for its health benefits due to a variety of bioactive compounds that contribute to its antioxidant and antibacterial properties. This study aimed to evaluate the antibacterial activity of six Moroccan monofloral honeys against seven pathogenic bacterial strains (Proteus mirabilis, Enterobacter aerogenes, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, all isolated from hospital patients. Thyme honey exhibited the highest phenolic content (188.71 ± 6.87 mg GAE/kg) and lowest IC50 in the DPPH assay (15.70 ± 5.15 mg/mL), indicating strong antioxidant activity. Antibacterial tests revealed Enterobacter aerogenes and Klebsiella pneumoniae as the most resistant strains, with minimum inhibitory concentration (MIC) values above 50% (w/v) across all honeys. Conversely, Staphylococcus aureus was the most sensitive, especially to honeys 2, 4, 5, and 6, with MIC values below 25% (w/v). HPLC analysis identified phenolic compounds such as gallic acid, vanillin, epicatechin, naringin, and rutin in honeys with high antibacterial activity, suggesting these compounds contribute to honey’s bioactive properties.
... The beneficial flavonoid and phenolic acid components in honey are identical between varieties, but their relative amounts change. The known antioxidant properties of flavonoids or phenolic acids, which are found in trace amounts in nature, are the primary source of honey's therapeutic benefits [40]. Apigenin, catechin, chrysin, galangin, genistein, isorhamnetin, kaempferol, luteolin, myricetin, quercetin, rutin, pinocembrin, etc., are important polyphenolic compounds of honey [41]. ...
Honey has been used for centuries due to its health-promoting properties. Honey and its bioactive compounds regulate oxidative stress, inflammation, and other biological activities, making it a promising natural remedy. Its role as anti-diabetic, wound healing, cardioprotective, anti-microbial, and hepatoprotective potential has been proven through in vitro and in vivo studies. Moreover, its role in disease management has been reported through the inhibition of pro-inflammatory enzymes and downregulation of pro-inflammatory cytokine expression and secretion. Besides, it exerts modulatory actions on various signaling pathways such as nuclear factor-κB, tumor suppressor genes, apoptosis, angiogenesis, and MAPK pathway. The main aim of this review is to present a wide-ranging overview of the current evidence regarding the impact of honey on the management of various pathogenic conditions. However, further research based on animal models and clinical trials is required to fully understand the mechanisms of action and safety in the management of various diseases. There is limited clinical data on honey and its mechanisms of action. However, comprehensive clinical studies are needed to fully investigate the potential health benefits of honey, including its efficacies, safety, bioavailability, and underlying mechanisms of action.
... These compounds are commonly employed as floral markers for identifying heather honey and chestnut honey, respectively. Furthermore, their utility extends to geographical identification, enabling the discernment and classification of honey based on its specific floral sources and geographical origin [103,106,107]. ...
Honey is a natural sweet substance produced from secretions of living parts of plants or excretions of nectar by Apis mellifera bees. There is a diversity of possible botanical sources responsible for the different types of honey. Portugal, in particular, is renowned for its abundant and varied melliferous flora, influenced by geographical regions and climatic conditions, resulting in the production of distinct monofloral and multifloral varieties. These honeys are intricately linked with their organoleptic characteristics and chemical composition, including phenolic compounds. These phytochemicals are secondary metabolites that are commonly responsible for diverse biological properties, such as antioxidant, antimicrobial, and anti-aging activities, and its multifaceted applicability extends across several industries, thus underscoring its pivotal role in the economic landscape. As a result of these benefits, the scientific community focuses its attention on this remarkable food matrix. Regrettably, honey production has witnessed a decline in numerous countries, including Portugal. This concerning trend has attracted the attention of researchers seeking to understand the underlying factors and explore potential solutions. This chapter will present a comprehensive review of Portuguese honey and its production process, focusing on chemical composition and biological properties. It will also highlight the influence of geographical origin and botanical sources.
... Among honey phenolic compounds, flavonoids and phenolic acids (including benzoic and cinnamic acid derivatives) are the most significant polyphenols, exhibiting various biological activities [58]. Some of them, such as GA, CA or chlorogenic acid, occur in various honeys regardless of their origin [59][60][61][62]. ...
Background
Honey has been successfully used in wound care and cosmetics because of its effective biological properties, including antibacterial, antioxidant, and anti-inflammatory activities. Polyphenols, particularly phenolic acids, are key honey components responsible for these beneficial effects. In recent years, there has been a growing demand for natural, ecologically friendly, and biodegradable products in the modern cosmetics and wound care market. This study aimed to identify and quantify phenolic acids in four Polish honey samples of different botanical origins (heather, buckwheat, linden and rapeseed) and to assess for the first time the permeation of the identified phenolic acids through the skin and their accumulation after the application of pure honey samples, as well as honey-based hydrogel and emulsion formulations.
Methods
The honey samples’ antioxidant activity and total phenolic content were determined using the DPPH and ABTS assays and the Folin–Ciocalteu method, respectively. Phenolic acids and volatile compounds were identified and quantified in honey samples using the HPLC-UV and GC-MS method, respectively. The biocompatibility of the honey samples was evaluated using a murine fibroblast cell line (L929). A Franz-type vertical diffusion cell with porcine skin was used to assess phenolic acid’s permeation and skin accumulation from different honey-based pharmaceutical formulations. The biodegradability of the prepared formulations was also characterised.
Results
Gallic acid, 3,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, coumaric acid, and 3-hydroxybenzoic acid were identified and quantified in the honey samples. Heather honey exhibited significantly higher antioxidant activity and total polyphenol content than the other honey samples. Heather, linden and buckwheat honey samples significantly decreased cell viability at concentrations of 5% and 2.5%, while rapeseed honey sample markedly reduced fibroblast viability only at 5%. Among the tested formulations - pure honey, hydrogel, and emulsion - higher skin permeation and accumulation rates of phenolic acids were observed with the prepared honey-based hydrogels than with the pure honeys and emulsions. Additionally, the prepared formulations were classified as partially biodegradable.
Conclusions
The obtained results confirmed the effectiveness of two pharmaceutical formulations in the form of a hydrogel or emulsion containing honey after applied topically. The inclusion of honey in the vehicle, in particular hydrogel increased the penetration of phenolic acids through the skin.
... Ils comprennent des non-flavonoïdes tels que les acides phénoliques et des flavonoïdes tels que les flavones, les flavonols, les flavanones, les flavanols, les anthocyanidines, les isoflavones et les chalcones [35]. Ces composés ont un noyau aromatique avec un ou plusieurs groupes hydroxyle dans leur structure. ...
... This can be explained by the type of sorbent used to purify phenolic fractions. Previous works have shown a higher ability to absorb compounds, mainly phenolic acids, by polymeric sorbents such as the Amberlite XAD-2 used in this work compared to other deposits, such as C18, which was attributed to their aromatic structure, which can sorb aromatic phenolic compounds via π-π interactions [47]. ...
Designing new forms of food, food additives, and nutraceuticals is necessary due to the growing needs of consumers, as well as the inflammation of civilization diseases, the prevention and treatment of which can be significantly supported by dietary intervention. For this reason, this study aimed to obtain highly bioactive preparations in the form of powders from the fruits, leaves, and flowers of six species of hawthorn (Crataegus L.) using solid phase extraction (SPE). Ultra-performance liquid chromatography analysis (UPLC-PDA-MS/MS) showed a high concentration of phenolic compounds (in the range from 31.50 to 66.06 mg/g), including the highest concentration in hawthorn fruit preparations. Fruit preparations also showed the highest antioxidant activity (through scavenging of O2˙⁻ and OH˙ radicals), antidiabetic activity (inhibition of α-amylase and α-glucosidase), and anticancer activity, mainly against colon cancer cells (Caco-2). At the same time, hawthorn flower preparations showed the highest biocompatibility against normal colon cells (CCD841CoN) and anti-inflammatory activity (trypsin inhibition). Correlation and principal component analysis (PCA) showed that the health-promoting potential was most influenced by the content of falavan-3-ols. The above findings provide a basis for the industrial use of the developed preparations, which is in line with the current trend in food technology related to the search for new sources of bioactive compounds and the design of highly bioactive food.
... Honey is reported to contain antioxidant compounds capable of scavenging free radicals that could induce oxidative damage to cells and cellular components [10][11][12]. These antioxidant compounds in the honey are reported to be the plant secondary metabolites ingested by the honeybees during visits to the forage plants [13]. Honey has anticancer, anti-inflammatory, and antimicrobial properties and a role in protecting chronic diseases [14][15][16]. ...
Honey is a natural substance synthesized by honeybees. Its physicochemical properties and antioxidant activities differ among honey types due to floral and entomological origins. This is a comparative study on the physicochemical and antioxidant properties of honey from Apis mellifera and Meliponula beccarii L. (stingless bee) collected from different sources. A. mellifera honey samples were collected from hives (n=13) and local markets (n=13). M. beccarii honey samples were collected from local markets (n=13). The honey samples were designated as A. mellifera fresh honey directly collected from hives (AMFH), A. mellifera honey collected from the local markets (AMMH), and stingless bees (M. beccarii) honey collected from markets (MBH). Physicochemical and antioxidant properties were analyzed using standard protocols. The antioxidant properties of the honey samples were assessed using total phenolic, flavonoids, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods. Honey from the stingless bee (MBH) had significantly (p<0.0001) higher (33.5±3.0%) moisture content, free acidity (113±5.0 meq/kg), and maltose (3.1±1.0), but significantly lower (p<0.001) levels of hydroxymethyl furfural (4.4±2.0 mg/kg), pH (3.0±0.0), EC (0.25±0.0 mS/cm), fructose (19.6±2.4%), glucose (18.2±1.62%), and sucrose (0.18±0.13, p<0.05) compared to A. mellifera honey collected from markets. Honey from the stingless bees had higher phenolic (273±9.0 mgGAE/100 g), flavonoid (41±21 mgQE/100 g), and antioxidant content (104±6.0 mgAAE/100 g); however, the differences were not statistically significant (p>0.05). Honey samples from the stingless bees had higher moisture, phenolic, flavonoid, and antioxidant contents but lower pH, HMF, sugar, ash, and electrical conductivity compared to A. mellifera honeys collected from markets. A. mellifera honey collected directly from the hive had higher quality than those purchased from markets. A strong awareness creation program is needed for consumers as well as honey producers to maintain the quality of honey.
... Flavonoids are present in tiny quantities in honey but significantly contribute to its nutritional and health properties [7]. Publications are available on flavonoids as a marker of the geographical [4] or biological origin [8] of honey or both [9]. ...
Nowadays, climate changes induce deviations in the composition of honey varieties characteristic of a specific geographic region. Therefore, according to Codex Alimentarius for honey, the slight variations in values of determined parameters cannot be strictly regarded as a sign of its adulteration. Here, modified methods are presented for preparing honey samples for inductively coupled plasma-optical emission spectroscopy (ICP-OES) analysis and the high-performance liquid chromatography (HPLC) method to use them as fast and reliable methods in the food industry. ICP-OES analysis suggested that all analysed honey samples are natural, and HPLC-DAD (diode-arrray detection) analysis on the flavonoids showed that one sample is probably not natural. Invertase activity showed an overlap with this HPLC-DAD finding but suggested more samples as possibly adulterated, which can be neglected due to possible thermal treatment of those natural samples, causing a decrease in invertase activity. Therefore, results obtained from the analyses of investigated honey samples based on the mineral content, number, and quantity of flavonoids, together with the invertase activity, indicated that the combination of analyses could be a reliable tool for determining the quality of honey samples.
... Kwasy fenolowe, głównie pochodne kwasu hydroksybenzoesowego i hydroksycynamonowego, występują niemalże we wszystkich częściach roślin -nasionach, korzeniach, liściach, korze i kwiatach. Pszczoły miodne, zbierając nektar, przenoszą te bioaktywne związki z nektaru roślin do miodu [38]. Wyniki badań dotyczące składu frakcji fenolowej miodów pokazują, że najczęściej w produktach tych występują kwasy fenolowe, takie jak kwas cynamonowy i jego pochodne -kwas kawowy, kwas p-kumarowy, kwas ferulowy, pochodne kwasu benzoesowegokwas galusowy, depsydy, czyli połączenia stanowiące estry dwóch lub więcej fenolokwasów, jak kwas chlorogenowy i kwas elagowy (rycina 2) oraz flawonoidy -kwercetyna, kemferol, luteolina, . ...
Wprowadzenie. Choroby neurodegeneracyjne występujące najczęściej u osób starszych stanowią globalny problem, na który nie ma skutecznego leczenia przyczynowego. Do jednych z najczęściej opisywanych chorób starzejącej się populacji należą: choroba Alzheimera (AD), choroba Parkinsona (PD), choroba Huntingtona (HD) i stwardnienie zanikowe boczne (ALS). Do patogenezy chorób neurodegeneracyjnych prowadzi wiele czynników biologicznych, takich jak stres oksydacyjny, dysfunkcja mitochondriów, zapalenie neuronów i gleju, akumulacja białek i aktywacja szlaków apoptotycznych. Ponieważ zaburzenia neurodegeneracyjne postępują powoli, nie ma rozstrzygającej opcji leczenia, która mogłaby zatrzymać rozwój choroby tych zaburzeń. W ciągu ostatnich kilku dekad roślinne substancje fenolowe są szeroko stosowanymi związkami naturalnymi o wyraźnych właściwościach terapeutycznych. Należące do tej klasy flawonoidy i kwasy fenolowe wykazują działanie przeciwzapalne, przeciwutleniające, przeciwnowotworowe, a także neuroprotekcyjne. Substancje te w znaczących stężeniach występują w szerokiej gamie produktów spożywczych oraz w produktach zbieranych i przetwarzanych przez pszczoły – w miodzie i pyłku pszczelim. Cel pracy. Celem przeglądu było zebranie i usystematyzowanie wiedzy na temat możliwości zastosowania produktów pszczelich (miodu i pyłku pszczelego) w terapii chorób neurodegeneracyjnych, w świetle bieżącej literatury naukowej. Metodyka badań. Do analizy piśmiennictwa wykorzystano bazy PubMed, Scopus, Sciene Direct, używając następujących słów kluczowych: „honey”, „bee pollen”, „flavonoids”, „phenolic acids”, „neuroprotective activity”, „Alzheimer's disease”, „Parkinson's disease”, „Huntington's disease”, „amyotrophic lateral sclerosis”, „depression”. Wyniki. Skład chemiczny frakcji fenolowej miodów nektarowych oraz pyłku pszczelego zależy od pochodzenia botanicznego. Wykazano, zarówno w testach in vitro, jak i in vivo, że związki polifenolowe zidentyfikowane w miodach o różnym pochodzeniu botanicznym i w pyłku pszczelim zwiększają funkcje poznawcze i minimalizują neuropatię mózgu poprzez różne mechanizmy. Zdolność tych składników do leczenia chorób mózgu jest determinowana przez ich zdolność dotarcia do struktur mózgu i bezpośredniej interakcji z neuronami, neurytami i glejem. W rezultacie uznawane są za naturalne środki wspomagające w przypadku wielu schorzeń, w tym problemów neurologicznych. Wnioski. Zgodnie z wynikami badań in vitro i in vivo, bioaktywne składniki fenolowe zidentyfikowane w miodzie i pyłku pszczelim mogą chronić przed chorobami neurodegeneracyjnymi, takimi jak choroba Parkinsona i choroba Alzheimera, choroba Huntingtona, stwardnienie zanikowe boczne oraz zaburzeniami, lękiem i smutkiem, stanowiącymi podstawę depresji. Do najczęściej opisywanych substancji z grupy flawonoidów należą: kwercetyna, kemferol, luteolina, mirycetyna, apigenina, pinocembryna, chryzyna, galangina, rutyna, katechina i naryngenina, natomiast z grupy kwasów fenolowych: kwas kawowy, kwas chlorogenowy, kwas galusowy, kwas cynamonowy, p-kwas kumarowy, kwas ferulowy, kwas elagowy.
... The electrochemical methods are versatile tools for rapid and low-cost analysis of materials and allow direct work on real samples. [20][21][22][23][24] The conventional electrochemical methods used in this field include voltammetry, potentiometry and impedance. In electrochemical methods, three-electrode system include reference, auxiliary and working electrodes, is usually used. ...
Gallic acid (GA) is a well-known polyphenol that occurs naturally in plants and is used as a chemical marker or standard antioxidant in analytical research. Here, a carbon paste electrode was modified with a nanocomposite of graphitic carbon nitride and gold nanoparticles (g-C3N4/AuNPs/CPE). The g-C3N4/AuNPs was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. Electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry methods were used to investigate the electrochemical behavior of GA on the electrode. EIS analysis exhibited lower charge-transfer resistance in g-C3N4/AuNPs/CPE than CPE; 250 vs 1500 Ω, respectively. The g-C3N4/AuNPs/CPE was used to GA sensing with limit of detection and linear response range of 0.025 and 0.16–4.10 μM, respectively via DPV. Then, the GA content in Iranian honey samples with different floral origins such as Ziziphus, Barberry, Thyme, Astragalus, Eucalyptus and Coriander was successfully determined. According to result, the fabricated electrochemical sensor could be useful for GA evaluation in food samples.
... Because of phenolic compounds' polar nature, the most widely used analytical technique applied for their characterization in a wide range of samples along with honey is LC coupled with MS, normally following extraction procedures with polar solvents, including water. In honey samples, the most common phenolic compounds are phenolic acids and flavonoids, mainly from the sub-classes of flavones, flavanols, and benzoic and cinnamic acid derivatives [67][68][69]. In comparison to nectar honey, honeydew honey typically contains higher levels of phenolic acid derivatives but lower levels of flavonoids. ...
Honeydew honey is produced by bees (Apis mellifera) foraging and collecting secretions produced by certain types of aphids on various parts of plants. In addition to exhibiting organoleptic characteristics that distinguish them from nectar honey, these honeys are known for their functional properties, such as strong antioxidant and anti-inflammatory activities. Despite their importance, they remain poorly characterized in comparison with flower honeys, as most studies on this subject are not only carried out on too few samples but also still focused on traditional chemical–physical parameters, such as specific rotation, major sugars, or melissopalynological information. Since mass spectrometry has consistently been a primary tool for the characterization and authentication of honeys, this review will focus on the application of these methods to the characterization of the minor fraction of honeydew honey. More specifically, this review will attempt to highlight what progress has been made so far in identifying markers of the authenticity of the botanical and/or geographical origin of honeydew honeys by mass spectrometry-based approaches. Furthermore, strategies devoted to the determination of contaminants and toxins in honeydew honeys will be addressed. Such analyses represent a valuable tool for establishing the level of food safety associated with these products. A critical analysis of the presented studies will identify their limitations and critical issues, thereby describing the current state of research on the topic.
... However, identifying these marker compounds in honey poses a challenge due to their low concentrations. Successful isolation and chemical identification heavily rely on the extraction and analysis methods utilized [110][111][112]. ...
Fallopia japonica (FJ), an invasive plant species known for its rich bioactive compounds, has been used for centuries in traditional Chinese medicine. Despite its significant beekeeping potential, this aspect of FJ remains underexplored. This research aims to investigate the antimicrobial and antibiofilm properties of FJ plants and honey. Notably, this study is the first to identify individual phenolic compounds in both FJ plant tissues and FJ honey, highlighting resveratrol as a marker of FJ honey. The study tested inhibitory activity against seven bacterial strains: Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, Salmonella enteritidis, and the yeast Candida albicans. Disk diffusion and microdilution methods were used to assess antimicrobial activity, while the crystal violet staining test evaluated antibiofilm activity. Results showed that FJ plant tissues and honey exhibited strong inhibition, particularly against Gram-negative bacterial strains. The most significant inhibition of biofilm formation, by both FJ plant tissues and honey, was observed against Staphylococcus aureus and Escherichia coli. A significant positive correlation was found between antimicrobial activity and individual polyphenols, especially resveratrol. The antibacterial and antibiofilm potential of FJ plant tissues and honey suggests promising applications in sustainable beekeeping. Further research is necessary to evaluate the bioactive compounds found in FJ honey and their health effects.
... This implies that the role of flavonoids in honey may be more complex and that, in contrast to polyphenols, they may not be the main contributors to total antioxidant capacity. Similar findings from earlier research suggest that honey's flavonoid content is not the only factor influencing its antioxidant efficacy [80,83,84]. For instance, Beretta et al. [85] found that the antioxidant properties of honey could not be attributed solely to its flavonoid composition, but rather involved a synergistic interplay between various phytochemicals, including polyphenols and other unidentified compounds. ...
Honey, with its varied and extensive characteristics, is a complex and diverse biological substance that has been used since ancient times. The aim of this study is to thoroughly characterize the physicochemical, phytochemical, and biological properties of four floral honey varieties from the Fez-Meknes region in Morocco, with the goal of promoting the valorization of Moroccan honey in skincare and cosmetic products. The analyses of their physicochemical characteristics encompass various parameters such as pH, acidity, density, water content, Brix index, conductivity, ash content, hydroxymethylfurfural (HMF) content, and color. The levels of polyphenols range from 22.1 ± 0.4 to 69.3 ± 0.17 mg GAE/100 g of honey, measured using the Folin–Ciocalteu method for polyphenol quantification. Additionally, the estimation of flavonoid quantities in 100 g of honey, conducted using the aluminum trichloride method, reveals values ranging from 3.6 ± 0.2 to 7.2 ± 0.6 mg QE. Furthermore, it is noteworthy that honey exhibits high levels of glucose and relatively low concentrations of proteins. The quantitative evaluation of antioxidant effects, carried out through the 2,2-diphenyl-1-picrylhydrazyl free-radical-scavenging method and the ferric-reducing antioxidant power (FRAP) method, highlights the strong antioxidant capacity of multifloral honey, characterized by low inhibitory concentration values (IC50 = 30.43 mg/mL and EC50 = 16.06 mg/mL). Moreover, all honey varieties demonstrate antibacterial and antifungal properties, with multifloral honey standing out for its particularly pronounced antimicrobial activity. The correlation analyses between phytochemical composition and antioxidant and antibacterial activities reveal an inverse relationship between polyphenols and IC50 (DPPH) and EC50 (FRAP) concentrations of honey. The correlation coefficients are established at R² = −0.97 and R² = −0.99, respectively. Additionally, a significant negative correlation is observed between polyphenols, flavonoids, and antifungal power (R² = −0.95 and R² = −0.96). In parallel, a marked positive correlation is highlighted between antifungal efficacy, DPPH antioxidant activity (R² = 0.95), and FRAP (R² = 0.92). These results underscore the crucial importance of phytochemical components in the beneficial properties of honey, meeting international quality standards. Consequently, honey could serve as a natural alternative to synthetic additives.
... Bee products such as honey, propolis, and bee pollen have been used for centuries as natural antioxidants and traditional therapies for their health benefts and as natural antioxidants [1][2][3]. Nowadays, natural products are now antimicrobial properties, while in vitro and in vivo studies have shown that honey limits wound infections, enhances tissue regeneration, and inhibits Gram-negative and Gram-positive bacteria [6][7][8] due to its low pH, osmotic efect, high sugar content, and the presence of hydrogen peroxide, polyphenols, phenolic acids, favonoids and methylglyoxal [9][10][11]. Te propolis has a Greek origin and means defense for ("pro") and the community for ("polis") [12,13]. ...
The current study used a design of experiments to evaluate the potential synergistic effects of three Moroccan bee products (honey (H), propolis (P), and bee pollen (BP)) on the free radical inhibition and antibacterial activity against clinical strains of Staphylococcus aureus and Escherichia coli. The phytochemical contents of these three bee products were first evaluated using HPLC-DAD with 20 identified compounds (9 in both H and P extracts and 13 in BP extract). The P extract had the highest phytochemical content, with high levels of flavanone pinocembrin, flavanol catechin, lignan pinoresinol, and simple phenolics (p-coumaric and gallic acids). Then, the optimized mixtures were determined using an augmented simplex-centroid design. The optimized formulations (H33%:P43%:BP24%) and (H21%:P47%:BP32%) presented the optimal total phenolic content and DPPH-IC50 with 226.88 mgGAE/g and 10.64 µg/mL, respectively, whereas the formulations (H26%:P52%:BP22%) and (H35%:P40%:BP25%) showed the optimal antimicrobial activity against S. aureus (MICS.aureus equal to 4.34 µg/mL) and E. coli (MICE.coli equal to 5.70 µg/mL), respectively. The predicted responses from these mixture proportions were also experimentally validated. Compared to the single free radical activity and antibacterial effect of each isolated bee product, these optimized formulations demonstrated an increased biological activity, and the determination of the fractional inhibitory concentrations revealed a synergistic effect between these products. This study emphasizes the interest in optimized bee product mixtures for practical applications beyond the pharmaceutical and food industries. Their potential can be extended to nutraceuticals, cosmeceuticals, animal health, environmental sustainability, and advanced biomedical research, offering holistic solutions for diverse challenges across various sectors. Exploring these applications further can unlock new avenues for innovation and sustainable development.
... Gradient, isocratic, or a combination of both elution techniques are commonly applied for the analysis of flavonoids. Nowadays, reversed phase ultra-high-performance liquid chromatography (UHPLC) is the most widespread technique used in separating and quantifying plant metabolites [123], due to its ability to produce a chromatogram at a shorter retention time with high resolution and high sensitivity [124]. ...
Herbal standardization is a crucial aspect in the field of herbal medicine and nutraceutical products. It refers to the process of developing and implementing standards to ensure the consistency, quality, and efficacy of herbal products. One important class of bioactive compounds that is widely distributed in plants is bioflavonoids, natural polyphenolic compounds. The significant pharmacological properties of bioflavonoids include antioxidant, anti-inflammatory, anti-diabetic, anti-aging and antimicrobial properties are promising therapeutic nutraceutical agents in the management of several acute and chronic diseases. However, the exploitation of these bioflavonoids demands systematic standardization approaches covering from extraction to enrichment of high-quality standardized multicomponent botanical extract in order to meet the desired efficacy. Hence, this review describes on the plant innovative processing technologies comprising of drying, solvent, extraction technique and adsorbent technologies accompanied with the established quality control methods using high end analytical instrument and omics technology. The importance of bioactive compound standardization and global demand of flavonoid in various applications are also highlighted.
... These belong to a group of compounds known as polyphenols, which are secondary metabolites of plants. 20 In the products, they originate from the nectar, plant exudates and resins that bees collect while foraging. 21 The chemical composition of honey and propolis is dependent on many factors such as bee species, vegetation and geographical location. ...
Background
Bee products are gaining interest in the field of research due to their biochemical and nutritive properties. Honey bee products have been researched extensively but little has been done in regards to stingless bees. There are many species of stingless bees including Plebeina armata, which are found in the Afrotropics. They are underground nesting and produce honey, propolis, wax, pollen and bee bread. These products are known to be rich in polyphenols that comprise of flavonoids and phenolic. In our study, we analysed colorimetrically the total flavonoid, phenolic content and radical scavenging activity of honey (n = 22) and propolis (n = 25) from Bomet, Kisii and Maralal in Kenya.
Results
Honey and propolis had total flavonoid content of 12.00–22.67 mg QE/100 g and 288.15–944.76 mg QE/100 g while total phenolic content was 87.01–239.93 mg GAE/100 g and 524.14–1225.01 mg GAE/100 g, respectively. In considerations to the regions, Maralal had the highest phenolic and flavanoid content followed by Bomet and Kisii was the least. The same trend was observed in the radical scavenging activity. Except for the total flavonoid content in honey, the difference was significant (p < 0.05).
Conclusion
The polyphenol content of both honey and propolis of P. armata are equally affected by geographical location as a result of different vegetation. They are good source of antioxidants, which can be utilized in diet due to their radical scavenging properties.
... In particular, the quality and quantity of polyphenols can be influenced by geographical region, floral source, climatic conditions, and bee type [17]. Studies suggest that the polyphenol profile of honey, such as p-coumaric, gallic acid, caffeic acid, and ferulic acid, can serve as a floral marker to verify its botanical origin [5,49,50]. The identification of flavonoid and phenolic compounds is a common approach, but it might be insufficient, warranting the need for quantitative analysis to provide a more comprehensive understanding of the composition and potential health implications of consuming honey. ...
Limited honey production worldwide leads to higher market prices, thus making it prone to adulteration. Therefore, regular physicochemical analysis is imperative for ensuring authenticity and safety. This study describes the physicochemical and antioxidant properties of Apis cerana honey sourced from the islands of Lombok and Bali, showing their unique regional traits. A comparative analysis was conducted on honey samples from Lombok and Bali as well as honey variety from Malaysia. Moisture content was found slightly above 20% in raw honey samples from Lombok and Bali, adhering to the national standard (SNI 8664:2018) of not exceeding 22%. Both honey types displayed pH values within the acceptable range (3.40–6.10), ensuring favorable conditions for long-term storage. However, Lombok honey exhibited higher free acidity (78.5±2.14 meq/kg) than Bali honey (76.0±1.14 meq/kg), surpassing Codex Alimentarius recommendations (≤50 meq/kg). The ash content, reflective of inorganic mineral composition, was notably lower in Lombok (0.21±0.02 g/100) and Bali honey (0.14±0.01 g/100) compared to Tualang honey (1.3±0.02 g/100). Electric conductivity, indicative of mineral content, revealed Lombok and Bali honey with lower but comparable values than Tualang honey. Hydroxymethylfurfural (HMF) concentrations in Lombok (14.4±0.11 mg/kg) and Bali (17.6±0.25 mg/kg) were slightly elevated compared to Tualang honey (6.4±0.11 mg/kg), suggesting potential processing-related changes. Sugar analysis revealed Lombok honey with the highest sucrose content (2.39±0.01g/100g) and Bali honey with the highest total sugar content (75.21±0.11 g/100g). Both honeys exhibited lower glucose than fructose content, aligning with Codex Alimentarius guidelines. The phenolic content, flavonoids, and antioxidant activity were significantly higher in Lombok and Bali honey compared to Tualang honey, suggesting potential health benefits. Further analysis by LC-MS/MS-QTOF targeted analysis identified various flavonoids/flavanols and polyphenolic/phenolic acid compounds in Lombok and Bali honey. The study marks the importance of characterizing the unique composition of honey from different regions, ensuring quality and authenticity in the honey industry.
... HPLC analysis of the honey phenolic compounds revealed that the most abundant compound in all samples was ellagic acid except for thyme honey ( Table 5). The obtained phenolic profiles are different from those reported in previous studies [79,80]. Variations in the phenolic profiles of honeys from the same botanical origin can originate from several factors, including environmental factors, botanical variability, bee behavior and foraging, processing and storage, and the analytical methods used to assess the phenolic profile of honey [81]. ...
Eight monofloral honey samples from different botanical and geographical origins in the central and eastern parts of Morocco were examined for their phenolic composition, capacity to scavenge free radicals, and ability to inhibit advanced glycation end–products. According to the melissopalynological analysis, the examined honey samples were considered to be natural honeys, and were classified as monofloral with very frequent pollen grains characteristic of each types of the selected Moroccan honey samples: Zantaz ( Bupleurum sp . ), fennel, thistle, eucalyptus, spurge, thyme, jujube, and carob. Our results showed that the average moisture content varied from 16.3 ± 0.1% to 19.9 ± 0.1%, and the mean color intensity ranged from 30.94 ± 7.42 to 166.9 ± 6.43 mm Pfund. The highest total phenolic content recorded was 163.83 ± 1.84 mg of gallic acid equivalent per kg, while the highest flavonoid content was 84.44 ± 1.20 mg of catechin equivalent per kg. Zantaz honey exhibited potent antioxidant capacity, as demonstrated by ABTS, DPPH, β-carotene bleaching, FRAP, and ORAC assays. The most significant results were obtained for the ORAC test, with the highest ORAC value of 4.65 mM Trolox equivalent per gram was recorded for Zantaz honey extract. HPLC–DAD analysis revealed different polyphenolic profiles, which can be attributed to differences in floral origin. Furthermore, our study revealed that the extracts of thistle honey, fennel honey, and Zantaz honey were the most effective glycation inhibitors, with the highest inhibition percentage of 96% obtained for the thistle honey extract.
... Considering the removal of any instrumental noise, the resulting spectral profiles of interest (i.e., 260-360 nm) was computed for further PCA. It is worth mentioning that such a spectral window contains absorbance signals attributed mainly to phenolic and flavonoid compounds (Pyrzynska & Biesaga, 2009). ...
... 5 Natural phytochemicals are mostly produced by plants and widely distributed in secretions (e.g., nectar) and various organs such as roots, stems, and leaves. 6 During the last decades, researchers have already identified a variety of phytochemicals such as phenolic acids, 7 aldehydes, 8 flavonoids, 9 and terpenes 10 in plant-derived honey. Gelam and Tualang honeys, for instance, were rich in phenolic acids such as caffeic acid, gallic acid, and ferulic acids, and these chemicals were simultaneously demonstrated to possess anti-inflammatory and antibacterial activities. ...
We aimed to identify the characteristic phytochemicals of safflower, Chinese sumac, and bauhinia honeys to assess
their authenticity. We discovered syringaldehyde, riboflavin, lumiflavin, lumichrome, rhusin [(1E,4E)-1,5-diphenylpenta-1,4-dien-3-one-O-cinnamoyl oxime], bitterin {4-hydroxy-4-[3-(1-hydroxyethyl) oxiran-2-yl]-3,5,5-trimethylcyclohex-2-en-1-one}, and unedone as characteristic phytochemicals of these three types of honeys. The average contents of syringaldehyde, riboflavin, lumiflavin, or lumichrome in safflower honey were 41.20, 5.24, 24.72, and 36.72 mg/kg; lumiflavin, lumichrome, and rhusin in Chinese sumac honey were 39.66, 40.55, and 2.65 mg/kg; bitterin, unedone, and lumichrome in bauhinia honey were 8.42, 26.33, and 8.68 mg/kg, respectively. To our knowledge, the simultaneous presence of riboflavin, lumichrome, and lumiflavin in honey is a novel finding responsible for the bright-yellow color of honey. Also, it is the first time that lumiflavin, rhusin, and bitterin have been reported in honey. We effectively distinguish pure honeys from adulterations, based on characteristic components and high-performance liquid chromatography fingerprints; thus, we seem to provide intrinsic markers and reliable assessment criteria to assess honey authenticity.
... Due to its speed, simplicity and convenience, HPLC-DAD is the most widely used among various chromatographic techniques (Irakli et al. 2012). Pyrzynska and Biesaga (2009) stated that routine detection in HPLC and CE typically relies on measuring UV absorption, usually using diode array detection (DAD), and that the DAD detector can simultaneously detect chromatograms of different wavelengths. For the analysis, the following were used as standards: gallic acid, sesamol, paracoumaric acid, benzoic acid, protocatechuic acid, catechin, syringic acid, vanillin, syringaldehyde, rutin, protocatechuic aldehyde, vanillic acid, rutin, 4-hydroxybenzoic acid, ferulic acid, coumarin, epicatechin, rosmarinic acid, t-cinnamic acid, quercetin, kaempferol, caffeic acid, and chyricin. ...
Volatile oil analysis, phenolic constituents, antioxidant capacity, antimicrobial activity, vitamin C, and enzyme activities of the fruits of Rhus coriaria L. were studied. The chemical with the highest percentage was sesquiterpene hydrocarbons with 40.4%. The major compound was detected as caryophyllene (36.9%). The main phenolic constituents of fruit samples were gallic acid, syringic acid, protocatechuic acid, and 4-hydroxybenzoic acid. The highest phenolic constituent of fruits was gallic acid. Ferric (III) ion reducing antioxidant power (FRAP) capacity (14.9 mg FeSO4 eq./g), free radical scavenging (ABTS) capacity (68.8 mg AA eq./g), ABTS % inhibition rate (98.0%), free radical scavenging (DPPH) (53.1 mg AA eq./g), and DPPH % inhibition (79.6%) amounts were determined in antioxidant capacities of the samples. The bioactive component contents of the samples were total antioxidant amounts (TAC) (32.8 mg GA/g), total flavonoid substance amounts (TFC) (73.8 mg QE eq./g), and total phenolic substance amounts (TPC) (41.4 mg GA eq./g). The results of the antimicrobial activity analysis of R. coriaria fruit samples showed antimicrobial activity against Staphylococcus aureus and Listeria monocytogenes microorganisms. The amount of vitamin C and enzyme inhibitor activity in the fruits of R. coriaria were determined as 35.5 mg/100 g and 0.07 mg/mL, respectively.
... Allah gave revelations to bees to make nests and produce honey that is useful for humans (Šarić et al., 2020). In chemistry, it turns out that the honey produced has chemical compounds such as flavonoids (Pyrzynska & Biesaga, 2009). These compounds are very useful for human health such as antioxidants, anti-cancer, and neutralizing free radicals (Masad et al., 2021) (Silva et al., 2021). ...
Qur’an surah An-Nahl verses 68 and 69 provide information about the nature of bees and their benefits for human life. Allah inspires bees to build nests and find food in trees, mountains, and places made by humans. This study aims to examine scientific information on bees in Surah An-Nahl verses 68 and 69. The research method is library research. The results showed that bees in Surah An-Nahl verses 68 and 69 produce honey, have a good life, have great teamwork, and give benefits to human life. Bee gives people good role models for human society, teamwork, and lifestyle. In science, bees produce pheromone chemical compounds that play a role in communication between bees in the colony. The pheromones produced by the queen bee can regulate the male bees and worker bees to be loyal to the queen bee and carry out their duties well. Qur’an Surah An-Nahl verses 68 and 69 give us information about the bee and honey. Allah gives a message to people to live like a bee to have a good social, good lifestyle, don’t destroy the environment, and give benefits to people like honey. Rasullullah advised us to consume honey for treatment. Honey functions as an antioxidant, anticancer, and energy source, healthy heart, control sugar level, and maintain a healthy body. Bee food is nectar, good nectar will produce high-quality honey. Chemical compounds that are often found in honey like glucose, flavonoid, alkaloid, saponin, and glycoside.
... The analysis of phenolic compounds in the BBR showed the presence of flavonoids and phenolic acids. This matched previously reported data on both honey and propolis that indicated the prevalence of the same two families of derivatives (Pyrzynska & Biesaga, 2009;Os es et al., 2020). ...
The purification of raw beeswax by melting produces a semi‐solid beeswax by‐product (BBR) composed by honey, resins and other constituents that is usually considered as a waste. In this article, the chemical characterisation of BBR is reported, with the aim to valorise this by‐product following the principles of the circular economy. Carbohydrates, hydrocarbons and minerals were among the main constituents. Flavonoids and phenolic acids represent 1.5% of the BBR, and their qualitative profile resembles the propolis. To assess its potential usefulness, the BBR was tested against gram‐positive and gram‐negative bacteria of clinical interest, and results were compared with the raw propolis. Klebsiella pneumoniae and Salmonella enterica were inhibited at concentrations ≥ 0.001 mg mL⁻¹, while Enterococcus faecalis and methicillin‐resistant Staphylococcus aureus from 0.01 mg mL⁻¹. Only BBR was active on Pseudomonas aeruginosa. Below the concentration of 1 mg mL⁻¹, no significant toxicity on Caco2 cells was observed. These results indicate that the BBR presents a polyphenol composition similar to propolis and a significant antibacterial activity. Thus, on the basis of these results, we suggest that the BBR can represent a sustainable alternative to propolis as food preservative or nutraceutical.
Honey and other bee products, including propolis, royal jelly, and bee pollen, are widely recognized for their medicinal properties. Among their numerous biological activities, their anti-inflammatory and immunomodulatory effects have gained significant attention in recent years. Immune and inflammatory disorders contribute significantly to the development of chronic conditions, including cancer and diabetes. Bee-derived products, along with their bioactive compounds such as polyphenols, have shown promising therapeutic effects in modulating inflammatory mediators. Studies indicate that these products help regulate tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6), and interleukin-7 (IL-7) levels while reducing reactive oxygen species (ROS) production. Additionally, both in vitro and in vivo research, along with clinical studies, highlight their role in enhancing immune responses by activating B and T lymphocytes. This review explores the molecular mechanisms underlying these properties, emphasizing the role of bioactive compounds such as flavonoids, phenolic acids, and proteins in modulating immune responses and reducing inflammation. Evidence from in vitro, in vivo, and clinical studies suggests that honey and bee products influence cytokine production, regulate immune cell activity, and mitigate oxidative stress, making them potential therapeutic agents for inflammatory and immune-related disorders. To gather relevant information, databases such as Google Scholar, PubMed, and ScienceDirect were searched using various keyword combinations, including immunomodulatory, anti-inflammatory, bee products, honey, propolis, royal jelly, bee venom, and bee pollen. Given their anti-inflammatory, immune-protective, antioxidant, anti-apoptotic, and antimicrobial properties, bee products remain a subject of interest for further clinical evaluation.
Honey is one of the most popular natural sweet substances. From a chemical point of view, it could be defined as a natural food mainly composed of sugars and water (W), along with other minor constituents such as minerals, vitamins, amino acids, organic acids, flavonoids, and other phenolic compounds and aromatic substances. Its composition is particularly variable, depending on its botanical and geographical origins. In addition to beneficial components, certain honeys may contain natural toxic compounds derived from specific botanical sources, which can pose health risks if consumed in high quantities. The stability of these bioactive and potentially toxic compounds, particularly in relation to storage conditions and the effects of processing, is crucial for ensuring honey’s nutritional value and safety. Analytical methods such as high-performance liquid chromatography (HPLC), gas chromatography–mass spectrometry (GC-MS), inductively coupled plasma mass spectrometry (ICP-MS), and nuclear magnetic resonance (NMR) spectroscopy are commonly employed for both identifying honey’s major compounds and detecting contaminants. The aim of this chapter is to describe the principal families of compounds present in honey, review the stability of these compounds, and discuss the analytical methods employed for their analysis, as well as their utility in discriminating honeys according to their origin and quality.
The analytical results from a study of 16 honey samples (extra white to dark honey color range) of phenolic compounds obtained using the single UV spectrum methodology and classical spectrophotometric methods (Folin–Ciocalteu and AlCl3 methods) are presented. The first method quantified all classes of phenolic compounds in honey’s SPE-C18 extract: the total hydroxybenzoic acid content (concentrations between 0.37 ± 0.05 and 4.46 ± 0.37 mg of gallic acid/g of honey), total hydroxycinnamic acid content (0.13 ± 0.03 and 2.76 ± 0.13 mg of ferulic acid/g of honey), and total flavonoid content (0.15 ± 0.03 and 1.63 ± 0.17 mg of quercetin/g of honey). The total phenolic contents were, on average, 1.86 ± 0.72 and 1.78 ± 0.79 times higher than the results obtained for raw honey and the SPE-C18 extract, respectively, using the classical Folin–Ciocalteu method. The total flavonoid contents, on average, were 6.02 ± 3.14 times larger and 0.66 ± 0.33 times smaller than the results obtained using the classical AlCl3 method for raw honey and SPE-C18 extract, respectively.
This study explored the effect of geographical and floral origins on the antioxidant activities of Saudi honey samples related to their content of short peptides originated from honeybee proteins. The studied antioxidants were the total protein concentration, catalase activity, phenolic acids and flavonoids. The antioxidant activity assays included were the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, the ferric reducing antioxidant power (FRAP) assay and Ascorbic acid Equivalent Antioxidant Capacity (AEAC). The studied honey samples were obtained from the southwestern region of Saudi Arabia, namely Asir (65) and Jazan (25). The floral origins of the honey samples were Acacia (51), Ziziphus (4) and polyfloral (35). The LC/MS technique was used to detect the short peptides and the mascot database was used to identify the short peptides, their precursor proteins and the protease enzymes that produce them. Jazan honey was characterized by high number of short peptides. The short peptides were originated from honeybee proteins by the action of proteases from the honeybees and bacteria. The antioxidant activity of the honey samples increase with the increase of their content of short peptides and proteins. The amino acids type and sequence of the short peptides qualify them to act as antioxidant, antimicrobial, anti-diabetic, anti-hypertension, immunomodulatory and cholesterol lowering peptides.
Objective: To provide an overview of the scientific evidence that supports the use of Apis mellifera honey as an antibacterial agent. Design/Methodology/Approach: An exhaustive review of scientific literature was carried out. The collected information included the different honey types that, according to the reports, have antibacterial properties. In addition, the related compounds, the main chromatographic methods used for their identification, and the main pathogens that have been studied were analyzed. Results: The antibacterial properties of honey (especially monofloral honeys) have been widely studied worldwide, focusing on their capacity to inhibit pathogenic bacteria. The different methods used to study honey include agar diffusion, disk diffusion, and broth and agar dilution. These properties have been attributed to honey, as a result of its high sugar content, low moisture content, and acidic pH, as well as the diversity of the chemical compounds —mainly hydrogen peroxide, methylglyoxal (MGO), phenolic acids, flavonoids, peptides, glycopeptides, and different proteins— that were identified by a chromatographic analysis. Study Limitations/Implications: Currently, the honey of bees (Apis mellifera) has great potential as an alternative to combat the antibiotic resistance of certain pathogens. Findings/Conclusions: Honey can inhibit both gram-positive and -negative bacteria, such as Escherichia coli, Staphylococcus aureus, Pseudomona aeruginosa, and Enterobacter. These characteristics are the result of the diverse chemical compounds of honey. In addition, these compounds widely change depending on the vegetation that surrounds the hives; therefore, honey from different geographical origins has unique characteristics, in terms of its composition and antibacterial activity.
Stingless bee honey, sometimes referred to as meliponine honey, pot honey and kelulut honey (Malaysia), is a distinctive and priceless variety of honey made by stingless bees. It is a novel and intriguing natural product with a variety of bioactive components, physiochemical characteristics and potential medicinal effects. This honey has attracted much attention, and due to these properties, it is also known as a miracle liquid. Honey made by stingless bees has a different composition than honey made by honeybees. The distinctive characteristics of stingless bee honey are revealed through physiochemical investigation. Compared to honey from Apis species, it often has lower water content, a higher acidity, and a higher electrical conductivity. The substance’s elevated acidity and electrical conductivity are attributed to its organic acids and minerals, which additionally enhance its antibacterial and antioxidant properties. It is a topic of great interest for more research and development due to its therapeutic potential in antibacterial, antioxidant, wound healing, anti-inflammatory, and antidiabetic applications. The use of stingless bee miracle liquid in many businesses and the promotion of its health advantages to consumers can both benefit from knowledge of the composition and characteristics of honey.
Neurodegenerative diseases (NDDs), such as Alzheimer’s, Parkinson’s, amyotrophic lateral sclerosis, Huntington’s, multiple sclerosis (MS), and stroke, have become increasingly prevalent and pose a significant burden on public health. NDDs are a group of disorders that are characterized by the progressive degeneration or loss of structure and function of nerve cells in the brain and nervous system. Honey, a natural product with various medicinal properties, has gained attention as a potential anti-neurodegenerative agent. Honey contains several bioactive compounds. These compounds have been shown to protect neurons against oxidative stress, reduce inflammation, and promote neuronal survival and regeneration. These properties can further delay the onset or progression of neurodegeneration in NDDs. Several studies have investigated the potential of honey to improve cognitive function and reduce the pathological features associated with NDDs. These findings suggest that honey could be a promising therapeutic agent for the prevention and treatment of neurodegenerative diseases, although further research will be needed to determine the optimal dosing and formulations for human use. Overall, this chapter discusses honey as a potential anti-neurodegenerative agent for the treatment and management of neurodegenerative diseases and as a source of information for neuroprotective drug discovery and development.
Beekeeping provides products with nutraceutical and pharmaceutical characteristics. These products are characterized by abundance of bioactive compounds. For different reasons, honey, royal jelly, propolis, venom, and pollen are beneficial to humans and animals and could be used as therapeutics. The pharmacological action of these products is related to many of their constituents. The main bioactive components of honey include oligosaccharides, methylglyoxal, royal jelly proteins (MRJPs), and phenolics compounds. Royal jelly contains jelleins, royalisin peptides, MRJPs, and derivatives of hydroxy-decenoic acid, particularly 10-hydroxy-2-decenoic acid (10-HDA), which possess antibacterial, anti-inflammatory, immunomodulatory, neuromodulatory, metabolic syndrome-preventing, and anti-aging properties. Propolis has a plethora of activities that are referable to compounds such as caffeic acid phenethyl ester. Peptides found in bee venom include phospholipase A2, apamin, and melittin. In addition to being vitamin-rich, bee pollen also includes unsaturated fatty acids, sterols, and phenolics compounds that express antiatherosclerotic, antidiabetic, and anti-inflammatory properties. Therefore, the constituents of hive products are particular and different. All of these constituents have been investigated for their properties in numerous research studies. This review aims to provide a thorough screening of the bioactive chemicals found in honeybee products and their beneficial biological effects. The manuscript may provide impetus to the branch of unconventional medicine that goes by the name of apitherapy.
Pour étudier leur qualité physico-chimique, quatre types de miel ont été échantillonnés dans la région de Beni Mellal-Khénifra au Maroc: miel d'agrumes, miel d'euphorbe, miel d'anis et miel de caroube. Cinq paramètres physico-chimiques ont été analysés: teneur en humidité, conductivité électrique, teneur en cendres, pH et hydroxyméthylfurfural (HMF). Les résultats ont montré des différences significatives dans la composition physico-chimique entre les divers échantillons de miel analysés. À l'exception du miel d'agrumes, tous les autres échantillons de miel sont conformes aux normes de qualité établies. Abstract In order to study their physico-chemical quality, four types of honey were sampled from Beni Mellal-Khenifra region in Morocco: citrus honey, euphorbia honey, carob honey and anise honey. Five physico-chemical parameters were analyzed: moisture content, electrical conductivity, ash content, pH, and hydroxymethylfurfural (HMF). The results showed significant differences in the physico-chemical composition among the analyzed honey samples. With the exception of citrus honey, all other honey samples comply with established quality standards.
Plants of the family Euphorbiaceae, particularly members of the genus Euphorbia, have long been known to yield latexes and extracts with a wide range of therapeutic properties. They are also renowned for providing unifloral honey that is produced and commercialized mainly in the Mediterranean region and is much appreciated owing to its medicinal properties. By better understanding the unique properties and potential uses of Euphorbia honey, also known as Daghmous, our overarching aim is to provide a detailed and exhaustive overview of this valuable and versatile natural resource. Our study conducted an extensive literature search across various databases, focusing on recent and peer-reviewed research related to Euphorbia honey. The bibliometric analysis carried out using the Scopus database revealed peaks in publication activity in recent years, and Morocco emerged as the leading country in Euphorbia honey research. The co-occurrence network illustrated a shift towards modern techniques like chemometrics, reflecting advancements in research methodologies. Euphorbia honey is distinct in various aspects. Based on its pollen composition, it has a high content of pollen grains originating from Euphorbia spurge (minimum of 25%). This honey possesses a dark amber color, attributed to specific nectar sources, and chemical composition, and it’s very rich in essential components like carbohydrates, proteins, phenolic compounds, and volatile organic compounds (VOCs). Euphorbia honey exhibits strong antioxidant and cytotoxic properties, suggesting its potential utility in medicine, cosmetics, and the food industry. In this review, we explored the characteristics, therapeutic merits, and potential challenges of Euphorbia honey, focusing on its quality parameters, microbial contaminants, chemical constituents, and the risk of adulteration, along with methods for determining its authenticity.
Annotation The aroma of honey depends on the aromatic content of the honey plants. It is most depicted in honey containing the aromatic substances of chestnut, linden, tobacco, lily and other specific plants. The aroma of honey depends on the content of aromatic substances in honey plants, in particular aromatic alcohol-tyrosol (distinguished by a specific aroma of honey). The article provides a quantitative tyrosol content of honey of different origins in Georgia and its wine. Quantitative determination of aromatic alcohol tyrosol showed that the amount of tyrosine in dark colored honey wine, chestnut, sunflower) was 3-5 mg/dm 3 ; As a result, the amount of aromatic alcohol tyrosol in the wine obtained from them increased to 11-13 mg/dm 3. As for light-colored honey (meadow, linden, acacia), the amount of amino acid tyrosine in them varies from 2-4 mg/kg, while the amount of tyrosine in wine made from them was 8-10 mg/dm 3 .
Ethnopharmacological relevance:
Man has used honey to treat diseases since ancient times, perhaps even before the history of medicine itself. Several civilizations have utilized natural honey as a functional and therapeutic food to ward off infections. Recently, researchers worldwide have been focusing on the antibacterial effects of natural honey against antibiotic-resistant bacteria.
Aim of the study:
This review aims to summarize research on the use of honey properties and constituents with their anti-bacterial, anti-biofilm, and anti-quorum sensing mechanisms of action. Further, honey's bacterial products, including probiotic organisms and antibacterial agents which are produced to curb the growth of other competitor microorganisms is addressed.
Materials and methods:
In this review, we have provided a comprehensive overview of the antibacterial, anti-biofilm, and anti-quorum sensing activities of honey and their mechanisms of action. Furthermore, the review addressed the effects of antibacterial agents of honey from bacterial origin. Relevant information on the antibacterial activity of honey was obtained from scientific online databases such as Web of Science, Google Scholar, ScienceDirect, and PubMed.
Results:
Honey's antibacterial, anti-biofilm, and anti-quorum sensing activities are mostly attributed to four key components: hydrogen peroxide, methylglyoxal, bee defensin-1, and phenolic compounds. The performance of bacteria can be altered by honey components, which impact their cell cycle and cell morphology. To the best of our knowledge, this is the first review that specifically summarizes every phenolic compound identified in honey along with their potential antibacterial mechanisms of action. Furthermore, certain strains of beneficial lactic acid bacteria such as Bifidobacterium, Fructobacillus, and Lactobacillaceae, as well as Bacillus species can survive and even grow in honey, making it a potential delivery system for these agents.
Conclusion:
Honey could be regarded as one of the best complementary and alternative medicines. The data presented in this review will enhance our knowledge of some of honey's therapeutic properties as well as its antibacterial activities.
High performance liquid chromatography with UV–Vis detection and post-column derivatization with fluorimetric detection was used for analysis of dyes used in Coptic textiles. To obtain the best separation of analyzed compounds composition of mobile phase was optimized. The best results were obtained for 25 mM phosphoric buffer at pH 2.5 with gradient change of methanol concentration (Table 1). As post-column reagents used to enhance fluorescence signal of analyzed compounds, solutions of Al(III), Ga(III), In(III), and Zn(II) were used. The highest increase of fluorescence signal was observed for Ga(III) and 10 mM solution of this ion was used for investigation of plant extracts and extracts from Coptic textiles.
The aim of this work was to establish a solid platform of analytical information for the definition/standardization of the antioxidant properties of honey. We investigated first the antioxidant/radical scavenging capacity of 14 commercial honeys of different floral and geographic origin, using a battery of spectrophotometric tests: Folin-Ciocalteu assay for phenol content (PC), ferric reducing antioxidant power (FRAP assay) for total antioxidant activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay for antiradical activity, absorbance:450 (ABS450) for color intensity and one fluorimetric method: ORAC, oxygen reactive antioxidant capacity for the antilipoperoxidant activity. Then the data from different procedures were compared and analysed by multivariate techniques (correlation matrix calculation, principal component analysis (PCA)). Significant correlations were obtained for all the antioxidant markers (r ranging from 0.933 to 0.716), with antioxidant properties strictly correlated to the phenolic content and honey color intensity. PCA found different clusters of honey based on the antioxidant power and very likely also on chemical composition. The results of this study demonstrated that only through a combination of antioxidant testings, comparative analyses, and chemometric evaluation we can achieve a strictly rigorous guideline for the characterization of the antioxidant activity of honey, an invaluable tool for the understanding/demonstration of its antioxidants linked therapeutic efficacy.
The concentrations of 23 chemical elements (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Pb, Sb, Se, Sr, Th, Tl, U, Zn) were determined in 51 honey samples of different botanical origin produced in Siena County (Italy). K, Ca, Na and Mg were the most abundant elements, with mean contents of 1195, 257, 96.6 and 56.7mg/kg, respectively. The Fe, Zn and Sr contents generally ranged from 1 to 5mg/kg. Except for Ba, Cu, Mn and Ni, the trace element contents were below 100μg/kg. The analytical data indicated a good level of quality of the honeys, especially with regard to the concentrations of toxic trace elements, such as As, Cd, Pb and Sb, and suggested a significant influence of the botanical origin on the element composition. Some local geological and geochemical features also seemed to affect the chemistry of the honey.
An optimization of the OPA method has made feasible separation and quantification of 23 amino acids, which include 5 infrequently searched for. Detection limits ranged from 0.24 to 10.1pmol in honey and from 29.1 to 0.42pmol in bee-pollen; reproducibility (C.V.) ranged from 5.3% to 20.4%; recoveries were above 78.8%. Forty monovarietal honey samples from ilex, oak, heather and chestnut-tree were analyzed for their free amino acid profiles. α-Aminoadipic acid and homoserine are reported for the first time in honeys. Thirty-two samples of Spanish bee-pollen, made of a majority of pellets from Cistus Ladanifer (67.1%) and Echium plantagineum (8.9%), were analyzed for their free and total amino acid profiles. Free γ-aminobutyric acid was extensively found with an average of 0.53mg/g, while Hser and Orn were infrequent. Manually separated monofloral pellets from Cistus ladanifer and Echium plantagineum were analyzed for their free amino acid contents (including proline): 32.46 and 21.87mg/g for the former and 22.18 and 12.23mg/g for the latter. In contrast, the total amino acid percentage (on a dry weight basis) was 13.95% for Cistus ladanifer and 32.22% for Echium plantagineum.
The HPLC phenolic profiles of 52 selected unifloral honey samples produced in Europe were analysed to detect possible markers for the floral origin of the different honeys. Lime‐tree (five markers), chestnut (five markers), rapeseed (one marker), eucalyptus (six markers) and heather (three markers) honeys had specific markers with characteristic UV spectra. In addition, the flavanone hesperetin was confirmed as a marker for citrus honey, as well as kaempferol for rosemary honey and quercetin for sunflower honey. Abscisic acid, which had been reported to be a possible marker for heather honey, was also detected in rapeseed, lime‐tree and acacia honeys. Ellagic acid in heather honey and the hydroxycinnamates caffeic, p ‐coumaric and ferulic acids in chestnut, sunflower, lavender and acacia honeys were also detected. The characteristic propolis‐derived flavonoids pinocembrin, pinobanksin and chrysin were present in most samples in variable amounts.
© 2001 Society of Chemical Industry
A GC-MS procedure is described for the simultaneous quantitatation of the minor and major constituents of honeys, as their
trimethylsilyl derivatives, from one solution, by one injection. Selected minor components (aliphatic and aromatic carboxylic
acids, members of various homologous series, together with o-phosphoric acid, proline and hydroxymethylfurfurol), have been
determined on the basis of their characteristic fragment ions, in the presence of extremely high excess of honeysaccharides.
Selective fragmentation of these minor compounds in the ion trap detector provided possibilities for distinguishing them.
The method permitted the simultaneous quantitation of o-phosphoric, malic, shikimic, citric/isocitric, quinic, margaric, oleic
and stearic acids, hydroxymethylfurfurol and proline with the extremely high sugar contents of honeys (fructose, glucose,
galacturonic acid, inositol, sucrose, trehalose, turanose, maltose, gentiobiose, isomaltose, raffinose, erlose, melezitose,
maltotriose, panose, isomaltotriose) and allowed the fast evaluation of sugar and acid constituents of fifteen honeys from
various floral and geological origin. Results revealed that (i) the minor components varied in the concentration range of
0.0001 to 0.43%, and, (ii) together with the saccharides of honeys made up the total of identified and determined constituents
from 87.8% to 98.5%. Quantitative evaluation of the minor constituents was performed on the basis of their selective fragment
ion values with an average reproducibility of 6.7% (RSD).
High performance liquid chromatograms of the phenolic fraction of 19 samples of New Zealand manuka honey, some with high levels of non-peroxide antibacterial activity and some with no such activity, were identical, which indicated that phenolic components of this honey are not responsible for the presence or absence of this activity in manuka honey. Similarly, the result showed that geography does not influence the phenolic composition of manuka honey. Antibacterial bee peptides and the antibacterial β-triketone leptospermone were not detected in manuka honey. Methyl syringate constituted approximately 70% w/w of the phenolic fraction of manuka honey and can be regarded as a floral marker for this honey. High performance liquid chromatographic profiles of the phenolic components of manuka, heather, clover and beech honeydew honeys were significantly different and could be used to differentiate honeys if they can be shown to be as consistent as those of manuka honey.
This review is concerned with analytical methods to prove the authenticity of honey. A special emphasis is put on suitable methods for the detection of the geographical and botanical origin of honey. Whereas the determination of some single parameters, such as 5-hydroxymethylfurfural (HMF), moisture, enzyme activity, nitrogen, mono- and disaccharides, and residues from medicinal treatment or pesticides in honey does not lead to any information about the botanical and geographical origin, there are some suitable methods based on the analysis of specific components or on multi-component analysis. Mostly, such methods give indications of the botanical origin, investigating flavonoids patterns, distribution of pollen, aroma compounds and special marker compounds. There are some other profiles of components which could probably be used for the detection of the geographical origin (e.g. oligosaccharides, amino acids, trace elements). In particular, the combination of methods could be a promising approach to prove authenticity, especially when modern statistical data evaluation techniques will be applied.
Aroma is an important quality factor in foods. The aroma of bee honey depends on volatile fraction composition, which is influenced by nectar composition and floral origin. Honey of unifloral origin usually commands higher commercial value, thus the floral determination and certification of unifloral honey plays an important role in quality control. This review concerns investigations made on the volatile fraction of bee honey by gas chromatography/mass spectrometry. Recent advances in extraction methods, results achieved, and comparisons of alternative dependable methods for determining floral origin of bee honey are discussed. We emphasize solid phase micro-extraction gas chromatography (SPME/GC) methodology and present some of the results obtained to date, plus the advantages and drawbacks of SPME/GS in comparison with other methods.
A capillary electrophoresis method to determine and quantify some compounds of the polyphenolic fraction of honey has been carried out. A detailed method optimization was performed to separate the phenolic compounds present in honey using a methanol-water extract of Rosemary honey. This manuscript reveals the difficulties presented to carry out the peak identification using UV-vis coupled to capillary electrophoresis as detection system in honey. Honey is a complex mixture of compounds that requires very effective separation techniques to allow the identification of the constituents of the polyphenolic fraction. In order to study this fraction of honey, a capillary electrophoresis method was proposed. The study of the polyphenolic fraction was firstly accomplished in rosemary honey. This honey was spiked individually with 22 commercial standards that have been found previously in honey. Only chrysin, pinocembrin, kaempferol, ferulic acid and p-coumaric acid could be identified, though chrysin and pinocembrin were overlapped. Because of this, only kaempferol and ferulic and p-coumaric acids were quantified. Furthermore, the method was applied in another five extracts of honey from different floral sources and the results obtained were similar. Therefore, other detectors such as the mass spectrometer should be employed to assign without any doubts the identity of the peaks present in the electropherogram of an extract of the polyphenolic fraction of honey.
The antioxidative effects of honey species and their related products were evaluated using a lipid peroxidation model system. The antioxidant activities of honey species gradually decreased with passage of time. Buckwheat honey was as effective as 1 mM α-tocopherol. Superoxide-scavenging activities of propolis and royal jelly were strongest among the honey species tested. 1,1-Diphenyl-2-picrylhydrazyl radical scavenging ability of sample species were lower than those of 1 mM ascorbic acid and α-tocopherol. Hydroxyl radical scavenging activity was very high in all honeys (over 77% inhibition). From the results of the bacterial test on storage of meat and muscle, each honey exhibited the inhibition of bacterial growth. In particular, propolis and royal jelly exhibited the strongest inhibitory effects against bacterial growth. This suggests that honey species from different floral sources possess strong antioxidative and antibacterial activities and are scavengers of active oxygen species.
The influence of dietary sunflower honey, propolis, and a flavonoid extract of propolis was examined on drug-metabolizing enzyme activities in rat liver and on microsome-mediated binding of benzo[a]pyrene to DNA. Characterization of flavonoids present in sunflower honey and propolis was achieved in order to assess the relative effects of different components of honey and propolis. Honey and propolis contained the same major flavonoids, pinocembrin, chrysin, galangin, and pinobanksin. The concentration of flavonoids was higher in propolis. Sunflower honey produced no significant changes on phase I and phase II enzyme activities and no modification of in vitro binding of benzo[a]pyrene to DNA. Propolis treatment produced an increase of ethoxyresorufin deethylase, pentoxyresorufin depentylase, ethoxycoumarin deethylase, glutathione transferase, and epoxide hydrolase activities. A flavonoid extract from propolis slightly enhanced only few enzyme activities, ethoxycoumarin deethylase and epoxide hydrolase. The induction pattern was similar to that observed with pinocembrin (a major flavonoid of propolis) administered solely. Binding of benzo[a]pyrene to DNA by microsomes from rats fed with propolis or a flavonoid extract from propolis was not significantly modified. These results contribute to identification of food or foodstuffs that can modify drug-metabolizing enzymes and binding of carcinogens to DNA.
This study presents a novel packed-column extractor coupled with an absorption system to improve the quality of oleoresin oils for Oolong and green teas, extracted by using carbon dioxide. The effect of various co-solvents on the extract is also examined. In addition, gravimetrical measurement and HPLC chromatographic analysis individually determine the amount of oleoresin oil and the concentration of four major catechins. According to those results, the mean contents in the extract are 7.0- and 10.0-fold higher in an addition of 95% ethanol than in no addition for green tea and Oolong tea, respectively. The ratio of four major catechins to caffeine is the highest in Soxhlet ethanol extraction for both green and Oolong teas.
Quercetin is a typical flavonoid ubiquitously present in vegetables and fruits, and its antioxidant effect is implied to be helpful for human health. The efficiency of extraction process and acidic hydrolysis parameters for HPLC analysis of quercetin present in glycosides and aglycone forms was investigated. Hydrolysis for 5min in the presence of 2.8M HCl as well as for 10min with 1.1M HCl efficiently released quercetin from rutin. The method developed in this study was applied for quantitative determination of quercetin in some food (onion, apple) and herbal (Hypericum perforatum and Sambucus nigra) products.
A solid-phase extraction procedure was applied to remove organic acids from honey. Malic, maleic, citric, succinic and fumaric acids were isolated with an anion-exchange cartridge. The different parameters which affected the extraction procedure were studied and optimised to establish the optimal conditions for maximum recovery of organic acids and minimum extraction of interferences. The optimised procedure used a cartridge which was activated with 10 ml of 0.1 M sodium hydroxide solution (percolation rate 3 ml/min). A 10 ml volume of honey solution was passed at a flow-rate of 0.5 ml/min. The cartridge was washed with 10 ml of water (3 ml/min) and organic acids were eluted with 4 ml of 0.1 M sulfuric acid (0.5 ml/min). This solution was injected directly into the chromatograph. When this procedure was carried out on standard solutions of organic acids, recoveries between 99.2 and 103.4% were found. If this procedure was applied to honey samples these recoveries were also satisfactory and ranged from 62.9 to 99.4%.
In the past two decades, combining a chromatographic separation system on-line with a spectroscopic detector in order to obtain structural information on the analytes present in a sample has become the most important approach for the identification and/or confirmation of the identity of target and unknown chemical compounds. In most instances, such hyphenation can be accomplished by using commercially available equipment. For most (trace-level) analytical problems encountered today, the combination of column liquid chromatography or capillary gas chromatography with a mass spectrometer (LC–MS and GC–MS, respectively) is the preferred approach. However, it is also true that additional and/or complementary information is, in quite a number of cases, urgently required. This can be provided by, for example, atomic emission, Fourier-transform infrared, diode-array UV–vis absorbance or fluorescence emission, or nuclear magnetic resonance spectrometry. In the present review, the various options are briefly discussed and a few relevant applications are quoted for each combination. Special attention is devoted to systems in which multiple hyphenation, or hypernation, is an integral part of the setup. As regards this topic, the relative merits of various combinations—which turn out to include a mass spectrometer as one of the detectors in essentially all cases—are discussed and the fundamental differences between GC- and LC-based systems are outlined. Finally, the practicability of more extensive hypernation in LC, viz. with up to four spectrometers, is discussed. It is demonstrated that, technically, such multiple hyphenation is possible and that, from a practical point of view, rewarding results can be obtained. In other words, further research in this area is certainly indicated. However, in the foreseeable future, using several separate conventional hyphenated systems will be the commonly implemented solution in most instances.
Ultra performance liquid chromatography™ (UPLC) takes advantage of technological strides made in particle chemistry performance, system optimization, detector design, and data processing and control. Using sub‐2 µm particles and mobile phases at high linear velocities, and instrumentation that operates at higher pressures than those used in HPLC, dramatic increases in resolution, sensitivity, and speed of analysis can be obtained. This new category of analytical separation science retains the practicality and principles of HPLC while creating a step‐function improvement in chromatographic performance.This review introduces the theory of UPLC, and summarizes some of the most recent work in the field.
The separation of thirteen flavonoids from honey by micellar electrokinetic capillary chromatography (MECC) is described. All the flavonoids were separated on a fused-silica column (75 cm × 75 μm I.D.) with 0.2 M sodium borate buffer (pH 8.0)-50 mM sodium dodecyl sulphate-10% methanol. These conditions were applied to the separation of flavonoids from lavender, rosemary, citrus and heather honey samples, to establish correlations between the flavonoid profiles and the botanical origin of honey. Citrus honey was characterized by the accumulation of hesperetin, lavender by luteolin, rosemary by 8-methoxykaempferol and heather by some unidentified flavonoids. The influence of the geographical origin on the honey flavonoid pattern was also studied by MECC. Honey samples from Spain, Mexico and Canada were analysed and no significant differences were found.
A non-parameter method based on the assumption of additive substituent increments on retention is employed for estimation of the effects of the substituents in the flavone ring on the retention in the reversed phase HPLC. The influence of OH-and OCH 3-groups in the positions: 3, 5, 6, 7, 8, 3 0 , 4 0 , and 5 0 on reversed phase HPLC retention is studied in a group of 21 flavones. The multiple linear regressions performed using 15 substituent codes as independent variables and the logarithm of the retention factor (log k) of each solute obtained with isocratic elution as dependent variables, gave a good correlation with R 2 from 0.9884 to 0.9984, and R ¯ 2 from 0.9535 to 0.9937. The regression coefficients confirm that incorporation of an OH-group does not necessarily reduce retention, and OCH 3-groups, depending on the position, can either cause a decrease or increase in retention. The proposed approach was used for prediction of the structure of an unknown flavone. The predicted substituent pattern of an unknown flavone found in an 1035 extract of Teucrium polium is then experimentally confirmed by mass spectrometry and nuclear magnetic resonance of the isolated flavone – cirsiliol.
Flavonoids and other phenolics of Tunisian honey samples and propolis were analyzed to find correlations between botanical and geographical origin and chemical composition. Flavonoid content of honey was very variable (20−2400 μg/100 g). The richest samples contained the characteristic propolis flavonoids, while those containing fewer flavonoids were devoid of these substances. This is a difference with honeys from temperate areas, in which the poplar-derived flavonoids are present in all honey samples. In Tunisian honeys, and propolis, a new flavonoid, myricetin 3,7,4‘,5‘-tetramethyl ether, was detected. This is characteristic of Cistus spp. leaf exudates. Another minor compound was identified as quercetin 3,7,3‘-trimethyl ether. They were present in high amounts in propolis but were only detected in small amounts in honey. These results show that in border areas, such as Tunisia, where poplars are not always available for propolis collection, other plant sources can be used and their constituents detected in honey. Keywords: Phenolics; honey; propolis; flavonoids; characterization; geographical origin; botanical origin
Thirty-two aliphatic dicarboxylic acids were identified as methyl esters in the methylated diethyl ether extracts of four unifloral grade New Zealand rewarewa (Knightea excelsa) honeys using combined gas chromatography-mass spectrometry (GC-MS). 2-Methoxybutanedioic acid (O-methylmalic acid) and 4-hydroxy-3-methyl-trans-2-pentenedioic acid are proposed as floral marker substances for New Zealand rewarewa honey. The total level of aliphatic dicarboxylic acids identified in the rewarewa honey samples ranged from 64 to 111 mg/kg with an average level of 88 mg/kg.
A novel electrochemical route to estimate the antioxidant capacity in honey samples is proposed just using flow injection analysis. The analytical strategy involved the selective oxidation of polyphenolic compounds using two different target potentials, +0.8 and +0.5 V, at two different pHs. An oxidation current obtained at the fixed potential was used as an analytical guide of the antioxidant activity of the target honeys. Chemometrics (correlation and principal component analysis, PCA) demonstrated the significance of the electrochemical protocol versus the traditional spectrophotometric ones in the evaluation of antioxidant capacity and revealed the role of detection potential as a screening variable. The proposed protocol is very simple and fast. However, the most relevant merit of the electrochemical procedure is its inherent versatility which allows the evaluation of the antioxidant activity under predesigned controlled oxidation conditions. In addition, since intercept was statistically zero, its corresponding antioxidant content using just a calibration factor is proposed thus simplifying the calibration-analysis process. As a result, an electrochemical antioxidant index (EAI) is proposed.
Electrochemical detection of quercetin has been carried out on glassy carbon electrodes modified with carbon nanotubes and Nafion (GC/Nafion-CNT). GC/Nafion-CNT electrodes did not show passivation effect that occurs on the unmodified electrodes and displayed better stability and reproducibility. Quercetin oxidation was most favorable in acidic conditions and current gradually decreased as the solution pH increased. No oxidation was observed when two OH groups in a catechol moiety were fully deprotonated. These electrodes enabled selective determination of quercetin in the presence of interfering species such as ascorbic acid, uric acid, glucose, and catechol in large excess. Quantification of quercetin in a yellow onion has been made and favorably compared with reported values. Good selectivity and high sensitivity obtained by Osteryoung sSquare-wave voltammetry can open new possibilities of direct quercetin determination in vegetables with a minimal sample treatment.
A comparative study of the recovery of flavonoids (both aglycones and glycosides) by different Amberlite XAD resins has been achieved. No significant differences in the percentages of recovery were found with the chemical nature and physical characteristics of the different resins. A flavonoid recovery higher than 90% is possible in a number of cases. The possibility of fractionating the adsorbed flavonoids by desorption with methanol: water mixtures has also been studied. The polystyrene resins (XAD-2, XAD-4 and XAD-16) were found to be more useful for fractionation purposes than the polyacrylic resins (XAD-7, XAD-8). The results suggest that Amberlite XAD-2 is the most suitable for the recovery and fractionation of flavonoids from plant extracts and foods rich in sugars and other polar compounds such as honey and fruit jams.
Nonaqueous capillary electrophoretic separation of a group of flavonoids (quercetin, myricetin, catechin, epicatechin) and resveratrol in wine was investigated in methanol at high pH. Malonate background electrolyte (pH* 13.5, ionic strength I = 14.2 mmol/L) provided highly repeatable separations of the analytes. Tests of untreated and coated (poly(glycidylmethacrylate-co-N-vinylpyrrolidone)) capillaries showed the analysis to be faster (6.5 min vs. 25 min) and the repeatability better in the coated capillaries. The coating procedure was simple and highly repeatable and the coating was stable during 40-45 runs. Determination of the last migrating peaks (epicatechin, resveratrol and catechin) was achieved merely by evaporating the wine samples and reconstituting the residue in methanol. For determination of the first migrating peaks (quercetin and myricetin) the samples were submitted to solid-phase extraction in C8 cartridges.
Apitherapy has become the focus of attention as a form of folk and preventive medicine for treating certain conditions and diseases as well as promoting overall health and well-being. In apitherapy, honey is the therapeutic agent used for dressing surgical wounds, burns or skin ulcers, as well as for dyspepsia, peptic ulcer, etc., because of its antioxidant activity. Therefore, it is important to determine the antioxidants in honey by analytical techniques. In the present study, the antioxidant activities of honeys from different floral sources were investigated by electron spin resonance (1,1-diphenyl-2-picrylhydrazyl (DPPH) and H2O2/NaOH/DMSO scavenging systems), liquid chromatography with coulometric array detection (LC-ED), and liquid chromatography with electrospray mass spectrometry (LC-MS). The antioxidant activities of some unifloral honeys (acacia, Chinese milk vetch, buckwheat and manuka) were evaluated using the radical scavenging systems. It was shown that DPPH radical scavenging activity was significantly different among the honeys, with buckwheat and manuka honeys having significantly higher scavenging activity than acacia honey. In addition, only manuka honey had specific scavenging activity for superoxide anion radicals. The compound responsible for this activity in manuka honey was identified by LC-ED and LC-MS. Careful examination of the LC-ED chromatographic patterns of manuka and other honey samples revealed a distinct peak in the chromatogram of manuka honey to be methyl syringate (MSYR). The radical scavenging activity of MSYR was specific for superoxide anion radicals, similar to the case of manuka honey. Copyright © 2005 Society of Chemical Industry
The electrophoretic behaviour of 13 flavonoids commonly found in medicinal plants has been studied. The performance of two modes of separation, capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MEKC), was assessed and compared. MEKC was found to be more effective for separation of the analytes. The effect of structure on the electrophoretic behaviour of the flavonoids is also discussed.
In this study, the multivariate partial least squares projections to latent structures (PLS) technique was used for modeling
the RP-HPLC retention data of 17 chalcones, which were determined with methanol-water mobile phases of different compositions.
The PLS model was based on molecular descriptors which can be calculated for any compound utilizing only the knowledge of
its molecular structure. The PLS analysis resulted in a model with the following statistics: r=0.976, Q=0.933, s=0.076, and
F=43.63. The adequacy of the developed model was assessed by means of crossvalidation and also, by PLS modeling of the retention
data of several chalcones reported by Walczak et al. [J. Chromatogr. 353, 123, (1986)], which were obtained using stationary
phases of different polarity (-NH2, DIOL,-CN, ODS, C8). The structural interpretation of the developed PLS model was accomplished by means of comparative correlations between
the nonempirical descriptors used in the model and the solvation parameters developed by Abraham. The results obtained in
this work provides evidence for the great potential of the topological approach for the development of quantitative structure-retention
relationship (QSRR) models.
Seven phenolic acids related to the botanical origins of nine monofloral Eucalyptus honeys from Australia, along with two abscisic isomers, have been analyzed. The mean content of total phenolic acids ranges from 2.14 mg/100 g honey of black box (Eucalyptus largiflorens) honey to 10.3 mg/100 g honey of bloodwood (Eucalyptus intermedia) honey, confirming an early finding that species-specific differences of phytochemical compositions occur quantitatively among these Eucalyptus honeys. A common profile of phenolic acids, comprising gallic, chlorogenic, coumaric and caffeic acids, can be found in all the Eucalyptus honeys, which could be floral markers for Australian Eucalyptus honeys. Thus, the analysis of phenolic acids could also be used as an objective method for the authentication of botanical origin of Eucalyptus honeys. Moreover, all the honey samples analyzed in this study contain gallic acid as the main phenolic acid, except for stringybox (Eucalyptus globoidia) honey which has ellagic acid as the main phenolic acid. This result indicates that the species-specific differences can also be found in the honey profiles of phenolic acids. Furthermore, the analysis of abscisic acid in honey shows that the content of abscisic acid varies from 0.55 mg/100 g honey of black box honey to 4.68 mg/100 g honey of bloodwood honey, corresponding to the contents of phenolic acids measured in these honeys. These results have further revealed that the HPLC analysis of honey phytochemical constituents could be used individually and/or jointly for the authentication of the botanical origins of Australian Eucalyptus honeys.
A comparison is presented of product ion mass spectra of protonated and deprotonated molecules of kaempferol-3-O-glucoside, quercitin-3-O-glucoside (isoquercitrin), quercitin-3-O-galactoside (hyperoin), apigenin-7-O-glucoside, luteolin-7-O-glucoside, genistein-7-O-glucoside, naringenin-7-O-glucoside (prunin), luteolin-4′-O-glucoside, luteolin-6-C-glucoside (homoorientin, known also as isoorientin), apigenin-8-C-glucoside (vitexin), and luteolin-8-C-glucoside (orientin) together with the product ion mass spectrum of deprotonated kaempferol-7-O-glucoside. All isomeric ions were distinguishable on the basis of their product ion mass spectra. For protonated 3-O-, 7-O-, and 4′-O-glycosides at a collision energy of 46–47 eV, homolytic cleavage of the O-glycosidic bond yielded aglycon Y+ ions, whereas in deprotonated 3-O-, 7-O-, and 4′-O-glycosides, heterolytic and homolytic cleavage of the O-glycosidic bond yielded radical aglycon (Y–H)− and aglycon (Y−) ions. In each case, fragmentation of either the glycan or the aglycon or both was observed. For 6-C- and 8-C-glycosides at a collision energy of 46–47 eV, fragmentation was restricted almost exclusively to the glycan. For luteolin-6-C-glucoside, the integrity of the aglycon structure is preserved at the expense of the glycan for which some 30 fragmentations were observed. Breakdown curves were determined as a function of collision energy for protonated and deprotonated luteolin-6-C-glucoside. An attempt has been made to rationalize the product ion mass spectra derived from C–O- and C–C-luteolin glucosides in terms of computed structures that indicate significant intramolecular hydrogen bonding and rotation of the B-ring to form a coplanar luteolin structure. It is proposed that protonated and deprotonated luteolin-6-C-glucoside may afford examples of cooperative interactive bonding that plays a major role in directing fragmentation.
LC–MS–MS is becoming a very important tool for the on-line identification of natural products in crude plant extracts. For an efficient use of this technique in the dereplication of natural products, a careful study of the parameters used to generate informative MS–MS spectra is needed. In this paper, the collision-induced dissociation (CID) MS–MS spectra of ubiquitous C-glycosidic flavonoids have been systematically studied using hybrid quadrupole time-of-flight and ion-trap (IT) mass analysers under various CID energy conditions. Efficient differentiation of flavonoid C-glycoside isomers was possible, based on the comparison of CID-MS–MS spectra of particular C-glycoside unit fragments. Striking differences between 6-C and 8-C flavonoid glycosides were especially observed in the product ion spectra of their 0,2X+ fragments ([M+H-120]+). Some guidelines for the on-line characterisation of C-glycosidic flavonoids by LC–MS–MS or LC–multiple-stage MS are given.
Flavonoids, phenolic acids and abscisic acid of Australian and New Zealand Leptospermum honeys were analyzed by HPLC. Fifteen flavonoids were isolated in Australian jelly bush honey (Leptospermum polygalifolium), with an average content of 2.22 mg/100 g honey. Myricetin (3,5,7,3′,4′,5′-hexahydroxyflavone), luteolin (5,7,3′,4′-tetrahydroxyflavone) and tricetin (5,7,3′,4′,5′-pentahydroxyflavone) were the main flavonoids identified. The mean content of total phenolic acids in jelly bush honey was 5.14 mg/100 g honey, with gallic and coumaric acids as the potential phenolic acids. Abscisic acid was quantified as twice the amount (11.6 mg/100 g honey) of the phenolic acids in this honey. The flavonoid profile mainly consisted of quercetin (3,5,7,3′,4′-pentahydroxyflavone), isorhamnetin (3,5,7,4′-tetrahydroxyflavone 3′-methyl ethyl), chrysin (5,7-dihydroxyflavone), luteolin and an unknown flavanone in New Zealand manuka (Leptospermum scoparium) honey with an average content of total flavonoids of 3.06 mg/100 g honey. The content of total phenolic acids was up to 14.0 mg/100 g honey, with gallic acid as the main component. A substantial quantity (32.8 mg/100 g honey) of abscisic acid was present in manuka honey. These results showed that flavonoids and phenolic acids could be used for authenticating honey floral origins, and abscisic acid may aid in this authentication.
The determination of contaminants and trace residues in honey has been of growing concern over the past few years, especially because these compounds can detract from the beneficial properties of honey, and, more importantly, if they are present in significant amounts, they can pose a serious threat to human health. Since honey has a complex matrix, it is often necessary to apply a clean-up step in order to eliminate interfering compounds prior to analysis. We briefly discuss the chemical composition and some medical properties of honey and describe the main sources of contamination of honey. We discuss the need for extensive sample preparation, including extraction and clean-up.
In this study, we investigated and compared some chemical properties and in vitro biological activities of three different types of Turkish honey. The first two honey samples were monofloral from chestnut and rhododendron flowers, collected from the east Black Sea region, and the third sample was the heterofloral form of astragalus (Astragalus microcephalus Willd.), thyme (Thymus vulgaris) and other several mountain flowers, collected from Erzincan in Eastern Anatolia. The chemical properties of the honey samples, such as total moisture, ash, total protein, sucrose, invert sugar, diastase activity, hydroxymethylfurfural content and acidity, were determined. Total phenolics, superoxide radical- and peroxynitrite-scavenging activities, and ferric reducing/antioxidant power measurements were used as antioxidant capacity determinants with ±-catechin, butylated hydroxytoluene, ascorbic acid, and trolox® used as reference. The antimicrobial activity was studied by the agar diffusion method, using eight bacteria and two yeasts. The mineral contents were also determined by an AAS method. The chestnut flower honey had the highest phenolic content, superoxide radical-scavenging activity and reducing power, while the heterofloral honey sample exhibited the highest peroxynitrite-scavenging activity. The antioxidant activities were also found to be related to the sample concentrations. The mineral content of the chestnut honey was much higher than the others. The samples showed moderate antimicrobial activity against some microorganisms, especially Helicobacter pylori ATCC 49503, Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, Candida tropicalis ATCC 13803 and Candida albicans ATCC 10231. The honey samples studied proved to be a good source of antioxidants and antimicrobial agents that might serve to protect health and fight against several diseases.
Thirty genuine honey samples were analyzed for pH, acidity, water, ash, net absorbance, total polyphenols (Folin–Ciocalteau method) and glucose, fructose, melezitose and erlose (as their trimethylsilyl oximes and trimethylsilyl ethers) by capillary gas chromatography. The resulting data were used, along with palynological analysis, to characterize the samples in relation to their possible source (nectar, honeydew and mixture honeys).Some minor components (carboxylic acids and cyclitols), eluting before monosaccharides, were also determined. One of these compounds was quercitol (1,3,4/2,5-cyclohexane-pentol), a deoxyinositol which has been previously determined in Quercus sp. samples. Quercitol was present in a broad concentration range (0.01–1.50 g/100 g) in honeys whose major source was honeydew but it was never higher than 0.01 g/100 g in samples characterized as nectar honeys. Quercitol concentrations appear to be related to the presence and amount of Quercus sp. honeydew as honey source, although further research is required to confirm this.
Electrochemical oxidation of quercetin, as important biological molecule, has been studied in 0.1 M phosphate buffer solution, using cyclic voltammetry, chronoamperometry, rotating disk electrode voltammetry as well as quantum mechanical calculations. The heterogeneous charge transfer rate constant, k′, transfer coefficient, α, and exchange current density, j0, for oxidation of quercetin at the glassy carbon electrode are determined as 4.84 × 10−2 cm s−1, 0.65 ± 0.01 and (1.17 ± 0.39) × 10−7 A cm−2, respectively. The formal potential, E0′, of quercetin is pH dependent with a slope of −60.1 mV per unit of pH which is close to the anticipated Nernstian value of −59 mV for a two electrons and two protons process. The standard formal potential, E0, of quercetin was found to be equal with 558 mV versus saturated calomel electrode (SCE). The mechanism of oxidation was deduced from voltammetric data in various pHs and also in different concentrations of quercetin. The diffusion coefficient of quercetin was calculated as 3.18 × 10−6 cm2 s−1 for the experimental condition, using chronoamperometric results. The results of density functional theory (DFT) calculations for the oxidation of quercetin in aqueous solution, are also presented. The theoretical standard electrode potential of quercetin is obtained to be 568 mV versus SCE, which is in good agreement with the experimental value. The discrepancy between theoretical and experimental values is only 10 mV. The agreement verifies the accuracy of experimental method and the validity of mathematical model.
Quercetin can effectively accumulate at multi-walled carbon nanotubes-paraffin oil paste electrodes (CNTPE) and cause a sensitive anodic peak at around 0.32 V (vs. SCE) in a 0.10 M phosphate buffer solution (pH = 4.0). Under optimized conditions, the anodic peak current is linear to quercetin concentration in the ranges of 2.0 × 10− 9−1.0 × 10− 7 M and 1.0 × 10− 7−2.0 × 10− 5 M, and the regression equations are ip (μA) = 0.0017 + 0.928c (μM, r = 0.999) and ip (μA) = 0.183 + 0.0731c (μM, r = 0.995), respectively. This paste electrode can be regenerated by repetitively cycling in a blank solution for about 2 min. A 1.0 × 10− 6 M quercetin solution is measured for 10 times using the same electrode regenerated after every determination, and the relative standard deviation of the peak current is 1.7%. The method has been applied to the determination of quercetin in hydrolysate product of rutin and the recovery is 99.2–102.6%. In comparison with graphite paste electrode, carbon nanotubes-nujol paste electrode and carbon nanotubes casting film modified glassy carbon electrode, the CNTPE gives higher ratio of signal to background current and better defined voltammetric peak.
A mass spectrometric method based on the combined use of electrospray ionization, collision-induced dissociation and tandem mass spectrometry at high mass resolution has been applied to an investigation of the structural characterization of protonated and deprotonated kaempferol (3,5,7,4′-tetrahydroxyflavone). Low-energy product ion mass spectra of [M+H]+ ions showed simple fragmentations of the C ring that permitted characterization of the substituents in the A and B rings. In addition, four rearrangement reactions accompanied by losses of C2H2O, CHO, CO, and H2O were observed. Low-energy product ion mass spectra of [M−H]− ions showed only four rearrangement reactions accompanied by losses of OH, CO, CH2O, and C2H2O. The use of elevated cone voltages permitted observation of product ion mass spectra of selected primary and secondary fragment ions so that each fragment ion reported was observed as a direct product of its immediate precursor ion. Product ion mass spectra examined at high mass resolution allowed unambiguous determination of the elemental composition of fragment ions and resolution of two pairs of isobars. Fragmentation mechanisms and ion structures have been proposed.
Eleven naturally occurring flavonoid aglycones, belonging to the representative flavone, flavonol, and flavanone types were separated by high performance liquid chromatography and analyzed on-line with negative ion electrospray ionization tandem mass spectrometry (ESI-MS/MS). In order to resolve the MS/MS spectra obtained, each compound was reinvestigated by direct loop injections using an ion trap mass spectrometer. The MSn
spectra obtained allowed us to propose plausible schemes for their fragmentation supported by the analysis of five complementary synthetic flavonoid aglycones. The negative ion ESI-MS/MS behavior of the different aglycones investigated in this study revealed interesting differences when compared with the previously described patterns obtained using various ionization techniques in positive ion. Thus, concerning the retro Diels-Alder (RDA) fragmentation pathways, several structurally informative anions appeared highly specific of the negative ion mode. In addition, a new lactone-type structure, instead of a ketene, was proposed for a classic RDA diagnostic ion. We also observed unusual CO, CO2, and C3O2 losses which appear to be characteristic of the negative ion mode. All these results and these unusual neutral losses show that the negative ion mode was a powerful complementary tool of the positive ion mode for the structural characterization of flavonoid aglycones by ESI-MS/MS.
The antioxidant activity of two selected Malaysian honeys, as well as their ethyl acetate extracts, were evaluated. The antioxidant activities were determined in terms of their anti radical power (ARP) as assessed by DPPH radical scavenging assay and their total antioxidant power (TAP), as assessed by FRAP assay. Total phenolic content of the extracts was determined according to the Folin-Ciocalteau procedure. The characteristic antioxidant activities showed a marked correlation with the total phenolic contents. These results indicated that honey has antioxidative and radical scavenging properties, which are mainly due to its phenolic content. This is the first report of the antioxidant properties of Malaysian honeys.
Flavonoids in Australian honeys from five botanical species (Melaleuca, Guioa, Lophostemon, Banksia and Helianthus) have been analyzed in relation to their floral origins. Tea tree (Melaleuca quinquenervia) and heath (Banksia ericifolia) honeys show a common flavonoid profile comprising myricetin (3,5,7,3′,4′,5′-hexahydroxyflavone), tricetin (5,7,3′,4′,5′-pentahydroxyflavone), quercetin (3,5,7,3′,4′-pentahydroxyflavone) and luteolin (5,7,3′,4′-tetrahydroxyflavone), which was previously suggested as a floral marker for an Australian Eucalyptus honey (bloodwood or Eucalyptus intermedia honey). These honeys of various floral species can be differentiated by their levels of total flavonoids, being 2.12 mg/100 g for heath honey and 6.35 m/100 g for tea tree honey. In brush box (Lophostemon conferta) honey, the flavonoid profile comprising mainly tricetin, luteolin and quercetin is similar to that of another Eucalyptus honey (yellow box or Eucalyptus melliodora honey). These results indicate that the flavonoid profiles in some of the Australian non-Eucalyptus honeys may contain more or less certain flavonoids from Eucalyptus floral sources because of the diversity and extensive availability of Eucalyptus nectars for honeybee foraging yearly around or a possible cross contamination of the monofloral honeys during collection, transportation and/or storage. Further analyses are required to differentiate and/or verify the botanical sources of the flavonoids that contribute to the flavonoid profiles of these honeys, by restricting honey sampling areas and procedures, employing other complementary analytical methods (e.g. pollen analysis, sugar profile) and using materials (e.g. nectar) directly sourced from the flowering plant for comparative studies. In Australian crow ash (Guioa semiglauca) honey, myricetin, tricetin, quercetin, luteolin and an unknown flavonoid have been found to be the main flavonoids, which is characteristic only to this type of honey, and could thus be used as the floral marker, while in Australian sunflower (Helianthus annuus) honey, the content of total flavonoids is the smallest amount comparing to those in the other honeys analysed in this study. However, the flavonoid quercetin and the flavonoid profile mainly consisting of quercetin, quercetin 3,3′-dimethyl ether (5,7,4′-trihydroxy-3,3′-dimethoxyflavone), myricetin and luteolin are characteristic only to this sunflower honey and could thus be used for the authentication.
Honey contains a variety of metals. Major metals are primarily derived from soil and nectar-producing plants, but consideration also needs to be given to environmental pollution or other anthropogenic sources of metals in honey, especially of Cd, Cr, Cu, Fe, Ni, Pb and Zn, which may present hazards to human health and adversely affect the quality and the safety of honey.This review surveys the literature from the past 15 years on determination of the metal content of honey by atomic absorption and emission spectrometries. It pays particular attention to sample treatment, sample preparation and measurement techniques. It also discusses the suitability of information on the composition of metals in honey for classifying according to botanical and geographical origin or indicating and controlling environmental pollution.
Eight phenolic acids and two abscisic acid isomers in Australian honeys from five botanical species (Melaleuca, Guioa, Lophostemon, Banksia and Helianthus) have been analyzed in relation to their botanical origins. Total phenolic acids present in these honeys range from 2.13 mg/100 g sunflower (Helianthus annuus) honey to 12.11 mg/100 g tea tree (Melaleuca quinquenervia) honey, with amounts of individual acids being various. Tea tree honey shows a phenolic profile of gallic, ellagic, chlorogenic and coumaric acids, which is similar to the phenolic profile of an Australian Eucalyptus honey (bloodwood or Eucalyptus intermedia honey). The main difference between tea tree and bloodwood honeys is the contribution of chlorogenic acid to their total phenolic profiles. In Australian crow ash (Guioa semiglauca) honey, a characteristic phenolic profile mainly consisting of gallic acid and abscisic acid could be used as the floral marker. In brush box (Lophostemon conferta) honey, the phenolic profile, comprising mainly gallic acid and ellagic acid, could be used to differentiate this honey not only from the other Australian non-Eucalyptus honeys but also from a Eucalyptus honey (yellow box or Eucalyptus melliodora honey). However, this Eucalyptus honey could not be differentiated from brush box honey based only on their flavonoid profiles. Similarly, the phenolic profile of heath (Banksia ericifolia) honey, comprising mainly gallic acid, an unknown phenolic acid (Ph1) and coumaric acid, could also be used to differentiate this honey from tea tree and bloodwood honeys, which have similar flavonoid profiles. Coumaric acid is a principal phenolic acid in Australian sunflower honey and it could thus be used together with gallic acid for the authentication. These results show that the HPLC analysis of phenolic acids and abscisic acids in Australian floral honeys could assist the differentiation and authentication of the honeys.
Propolis was mixed with ethanol at a ratio of 1:10 (v/w) for 24 h to yield propolis ethanol extract (E). Extract E was further fractionated with supercritical carbon dioxide (SC-CO2) into four fractions (R, F1, F2 and F3). To evaluate the selectivity of the fractionation, extracts corresponding to four fractions were characterized in terms of total flavonoid contents, antioxidant abilities and antioxidant mechanisms. Experimental results indicated that fractionation altered the composition distributions of fractions, e.g., by reducing total flavonoid contents. The antioxidant ability, metal chelating capacity, reducing power, and scavenging capacity of DPPH, O2·−or ·OH radicals of propolis extract and fractions increased with propolis concentrations. The effects of scavenging on DPPH of propolis extract and fractions, at 2 mg/ml were R (93%), E (75%), F1 (56%), F2 (47%), and F3 (27%). At a concentration of 1 mg/ml, propolis fractions scavenged O2·− by over 73% and all the fractions trapped around 65% of the ·OH groups. This in vitro study of antioxidant effects showed that R and F1 were the best fractions, followed by F2.
A method based on capillary electrophoresis with electrochemical detection (CE-ED) was developed for the determination of daidzein, rutin and quercetin. The effects of some important factors such as the acidity and concentration of running buffer, separation voltage, injection time, and detection potential were investigated to acquire the optimum conditions. The working electrode was a 300 μm diameter carbon disc electrode positioned opposite the outlet of capillary. The three analytes could be well separated within 10 min in a 40 cm length capillary at a separation voltage of 12 kV in a 100 mmol/l borate buffer (BB, pH 9.0). The response was linear over three orders of magnitude with detection limits (S/N=3) ranged from 0.190×10−6 to 0.434×10−6 mol/l for all compounds. This proposed method demonstrated good long-term stability and reproducibility with relative standard deviations (R.S.D.) of less than 5% for both migration time and peak current (n=7). It has been successfully applied for the determination of rutin and quercetin in Chinese traditional drug, Flos Sophorae buds and in the leaves of Ligustrum lucidum Ait. and Cinnamomum camphora (L.) Presl.