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Secondary metabolites from Eucalyptus grandis wood cultivated in Portugal, Brazil and South Africa
Abstract
The composition of the lipophilic and phenolic fractions of the wood of Eucalyptus grandis cultivated in Portugal, Brazil and South Africa, was studied. The lipophilic fraction of the studied E. grandis wood is mainly composed of sterols, fatty acids and phenolic compounds. Three triterpenic acids were detected for the first time in the wood extracts from Brazil. E. grandis wood from Portugal presents the largest lipophilic content (1.67 g kg⁻¹ of dry wood), followed by South Africa (1.56 g kg⁻¹ of dry wood) and Brazil (1.05 g kg⁻¹ of dry wood). 51 Phenolic compounds were identified in E. grandis wood MeOH:H2O extracts, from which 11 are reported for the first time as E. grandis constituents and 4 phenolic compounds are firstly reported as Eucalyptus genus components. E. grandis wood from Brazil shows the highest phenolic content (∼2.36 g kg⁻¹ of dry wood), followed by South Africa (∼1.90 g kg⁻¹ of dry wood) and Portugal (∼1.30 g kg⁻¹ of dry wood), demonstrating the influence of the geographic origin over E. grandis wood extractives composition and abundance, as well as on the antioxidant activities of the phenolic fractions. The detailed knowledge of these E. grandis extracts can contribute on the one hand to prevent their impact in the bleaching process, and, on the other demonstrates the potential of this species as a source of bioactive phytochemicals for nutraceutical applications.
... Additionally, higher levels of nonstructural carbohydrates are associated with less wood biomass loss, suggesting their potential as stress indicators in eucalyptus clones (Pizzi, 2016). Santos et al. (2017) detected differences in phenolic compound concentrations and antioxidant potentials in eucalyptus samples based on their origin. The existence of common response mechanisms to water deficits and physiological disorders (Picoli et al., 2021;Caetano-Madeira et al., 2023) corroborates the idea that different metabolites or their concentrations in the bark and wood may contribute to EPD-tolerant phenotypes. ...
... Ideally, in addition to reflecting the ability of trees to respond to and adapt to environmental stresses markers should be reliable, reproducible, informative, and easily and quickly accessed (Picoli et al., 2021). HPLC and colorimetry assays were selected for their specificity (Wallis and Foley, 2005;Miranda et al., 2016;Santos et al., 2017) and practicality (Chow and Landh€ ausser, 2004;Razouk et al., 2022) in detecting carbohydrates in woody samples, respectively. ...
... The differences in gallic acid concentrations between E. grandis, E. urophylla, and their hybrids may have been inherited based on the contribution of the parent species. Santos et al. (2017) found variations in the proportions of phenolic compounds in E. grandis samples, with significant differences between plants grown in Brazil and Africa. Dias et al. (2017aDias et al. ( , 2023 emphasized the significance of specific phenolics, such as gallic acid, caffeic acid, and quercetin, extracted from leaf samples to distinguish eucalyptus clones that are tolerant to water stress. ...
Despite favorable adaptations to soil and climate conditions in Brazil, eucalyptus cultivation faces challenges, such as physiological disorders linked to abiotic stresses. Symptomatology of the disorder involves lesions, swelling, and cracking of the bark and branches, increased sprouting, leaf abscission, and even plant death. Commercial eucalyptus clones were selected based on their response to and the occurrence of eucalyptus physiological disorder (EPD) under field conditions. A field experiment was conducted using a randomized block design consisting of 30 clones, from which nine genotypes were selected based on divergent phenotypes. Three trees per clone were sampled along the stem at the diameter at breast height (DBH) and 50% and 75% of the commercial height. Historical data on clone behavior and EPD scores assigned to the sampled trees were used as references for the comparison of chemical variables. The concentrations of soluble carbohydrates (total, reducing, and non-reducing), starches, phenolics, total amino acids, caffeic acid, quercetin, and gallic acid were estimated in the bark and wood samples. The analyses were conducted using compound samples processed for nutritional evaluation, aiming for ease and speed of obtaining the results. The methodologies used for quantifying the compounds were enzymatic and colorimetric assays for carbohydrates, colorimetric assays for phenolics and total amino acids, and laboratory techniques, such as pH measurement, electrical conductivity, and high-performance liquid chromatography (HPLC) for phenolics. The aim of these methods were to efficiently obtain data from sampled trees. Certain chemical properties of both bark and wood are associated with tolerant EPD phenotypes. Starch (1.81-6.84 g 100g-1), total phenolics (1.18-5.77 g 100 g-1) and amino acids (0.95-1.33 mmol kg-1), concentration in did not separate the tolerant from the susceptible genotypes. The same was observed for total phenolics (1.78-3.09 g 100g-1), amino acids concentration (1.13-1.40 mmol kg-1), and electrical conductivity (7.73-12.24 µS cm-1) in bark, despite both bark and wood samples exhibited significant differences among the tested genotypes. Significant correlations of electrical conductivity (ECB = 0.57), pH (PHB = −0.80), total amino acids (AB = 0.60), and quercetin (QEB = −0.47) in bark, and pH (PHW = −0.78), total amino acids (AW = 0.44), and gallic acid (GAW = −0.55) in wood samples, indicate their importance in the plants' response to triggers associated with the disorder, here considered as the expected phenotype score (FDE). Significant differences were observed between the pH of the solution or filtrate from bark and wood samples, from 4.4 to 6.3 in the susceptible, and from 5.0 to 7.2 in the tolerant clones, suggesting a potential role in distinguishing clones with varying EPD scores.
... Myrtaceae plants also contain phytosterols ( Figure 1C). Several recent reports characterized this class of natural compounds among Eucalyptus species (Eucalyptus botryoides, Eucalyptus camaldulensis, Eucalyptus globulus, Eucalyptus grandis, Eucalyptus maculata, Eucalyptus pellita, Eucalyptus rudis, Eucalyptus sideroxylon, and Eucalyptus viminalis) (Arisandi et al. 2020;Ferreira, Miranda, and Pereira 2018;Gominho et al. 2020;Rodrigues et al. 2018;Santos et al. 2017). These studies indicated β-sitosterol as the most prevalent compound, regardless of the investigated plant part. ...
... es: soxhlet extraction, conventional solid-liquid, ultrasound and supercritical CO 2 . The use of organic solvents (such as dichloromethane or methylene chloride with methanol) is a common choice to extract triterpenes, especially for Soxhlet extraction (Arisandi et al. 2020;Gominho et al. 2020Gominho et al. , 2021Okba, El Gedaily, and Ashour 2017;S. A. O. Santos et al. 2017). In the case of conventional liquid-solvent extraction, different solvents have been used and include methanol or ethanol in aqueous or ternary solutions with hexane, NaOH, and formic acid (Acín et al. 2021;Ceballos et al. 2018;Flores et al. 2015;Lima et al. 2015). ...
... In case of phytosterols, the use of soxhlet extraction is the most common method reported in literature for different species of the Myratceae family (Arisandi et al. 2020;Ferreira, Miranda, and Pereira 2018;Gominho et al. 2020;Prommaban et al. 2020;P. F. Rodrigues et al. 2018;S. A. O. Santos et al. 2017). Conversely, conventional solid-liquid extraction method is less reported (Correia et al. 2018;Lazzarotto-Figueiró et al. 2021). Supercritical CO 2 extraction recieved attention from researchers as potential alternative method to obtain phytosterols from Myratceae family (Canabarro et al. 2020;Narváez-Cuenca et al. 2020). Particularly f ...
Myrtaceae is one of the most important plants families, being regarded as the eighth largest flowering plant family. It includes many genera of utmost ecological and economical importance distributed all over the world. This review aimed to report the latest studies on this family focusing on certain widely used plants including Eucalyptus sp., Eugenia sp. (Eugenia uniflora, Eugenia sulcata), Syzygium sp. (Syzygium aromaticum and Syzygium cumini), Psidium sp., Pimenta dioica, Myrtus sp. (Myrtus communis), Myrciaria sp. and Melaleuca alternifolia. The extraction of bioactive compounds has been evolving through the optimization of conventional methods and the use of emerging technologies. Supercritical CO2 was applied for essential oils and ultrasound for polyphenols leading to extracts and essential oils rich in bioactive compounds. Advances in the field of encapsulation and delivery systems showed promising results in the production of stable essential oils nanoemulsions and liposomes and the production of plant extracts in the form of nanoparticles. Moreover, a significant increase in the number of patents was noticed especially the application of Myrtaceae extracts in the pharrmacuetucal field. The applications of ceratin plants (Pimenta dioica, Melaleuca alternifolia, Syzygium aromaticum essential oils or Myrciaria cauliflora peel extract) in food area (either as a free or encapsulated form) also showed interesting results in limiting microbial spoilage of fresh meat and fish, slowing oxidative degradation in meat products, and inhibiting aflatoxin production in maize. Despite the massive literature on Myrtaceae plants, advances are still necessary to optimize the extraction with environmentally friendly technologies and carry out risk assessment studies should be accomplished to harness the full potential in food, industrial and pharmaceutical applications.
... The total phenolic content (TPC) of Salix spp. barks was determined using the Folin-Ciocalteu reagent, according to procedures carried out elsewhere [34,35], with some alterations. In a 96-well plate, 150 µL of Folin-Ciocalteu reagent previously diluted 1:10 (v/v) with water, and 120 µL of 75 g L −1 sodium carbonate aqueous solution were added to 30 µL of Salix spp. ...
... The DPPH• scavenging effect of Salix spp. bark extracts was measured according to a former method [34], with slight modifications for 96-well microplate scale. Ascorbic acid was used as the natural antioxidant reference. ...
... The ABTS radical cation (ABTS• + ) scavenging effect of Salix spp. bark extracts was assayed based on the methodology reported elsewhere [34,37], which was adapted to the 96-well microplate scale. Ascorbic acid was used as the reference antioxidant. ...
Salix spp. have been exploited for energy generation, along with folk medicine use of bark extracts for antipyretic and analgesic benefits. Bark phenolic components, rather than salicin, have demonstrated interesting bioactivities, which may ensure the sustainable bioprospection of Salix bark. Therefore, this study highlights the detailed phenolic characterization, as well as the in vitro antioxidant, anti-hypertensive, Staphylococcus aureus growth inhibitory effects, and biocompatibility of Salix atrocinerea Brot., Salix fragilis L., and Salix viminalis L. bark polar extracts. Fifteen phenolic compounds were characterized by ultra-high-performance liquid chromatography-ultraviolet detection-mass spectrometry analysis, from which two flavan-3-ols, an acetophenone, five flavanones, and a flavonol were detected, for the first time, as their bark components. Salix bark extracts demonstrated strong free radical scavenging activity (5.58–23.62 µg mL⁻¹ IC50 range), effective inhibition on angiotensin-I converting enzyme (58–84%), and S. aureus bactericidal action at 1250–2500 µg mL⁻¹ (6–8 log CFU mL⁻¹ reduction range). All tested Salix bark extracts did not show cytotoxic potential against Caco-2 cells, as well as S. atrocinerea Brot. and S. fragilis L. extracts at 625 and 1250 µg mL⁻¹ against HaCaT and L929 cells. These valuable findings can pave innovative and safer food, nutraceutical, and/or cosmetic applications of Salix bark phenolic-containing fractions.
... Compounds were identified by comparing their mass spectra (MS) with the equipment's mass spectral library (NIST Mass Spectral Library), with data from the literature [34][35][36][37][38][39][40][41][42][43], and by the co-injection of standards. ...
... Nineteen fatty acids (33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51) were identified in the P. pinaster and P. pinea bark lipophilic extracts, accounting for 16% and 39% w/w of the total content of identified components, respectively (Table 1). Among the fatty acids, fourteen were saturated and four unsaturated, and their chain length varied between 6 and 26 carbon atoms. ...
... Indeed, docosanoic acid (43) was the major saturated fatty acid, whereas (9Z)-octadec-9-enoic acid (48) was the major unsaturated fatty acid. Considering the fatty acid composition of P. pinaster bark, all of the presented constituents of this family were herein identified for the first time, with the exception of tetradecanoic acid (37), hexadecanoic acid (39), and (9Z)-octadec-9-enoic acid (48) [50]. On the other hand, hexanoic acid (33), octanoic acid (34), nonanoic acid (35), decanoic acid (36), tricosanoic acid (44), hexacosanoic acid (46), and (11Z)-eicos-11-enoic acid (50) were identified for the first time in P. pinea bark in the present work. ...
The chemical composition of lipophilic bark extracts from Pinus pinaster and Pinus pinea cultivated in Portugal was evaluated using gas chromatography-mass spectrometry. Diterpenic resin acids were found to be the main components of these lipophilic extracts, ranging from 0.96 g kg⁻¹ dw in P. pinea bark to 2.35 g kg⁻¹ dw in P. pinaster bark. In particular, dehydroabietic acid (DHAA) is the major constituent of both P. pinea and P. pinaster lipophilic fractions, accounting for 0.45 g kg⁻¹ dw and 0.95 g kg⁻¹ dw, respectively. Interestingly, many oxidized compounds were identified in the studied lipophilic extracts, including DHAA-oxidized derivatives (7-oxo-DHAA, 7α/β-hydroxy-DHAA, and 15-hydroxy-DHAA, among others) and also terpin (an oxidized monoterpene). These compounds are not naturally occurring compounds, and their formation might occur by the exposure of the bark to light and oxygen from the air, and the action of micro-organisms. Some of these compounds have not been previously reported as lipophilic constituents of the bark of the referred pine species. Other constituents, such as aromatic compounds, fatty acids, fatty alcohols, and sterols, are also present in the studied extracts. These results can represent an opportunity to valorize P. pinaster and P. pinea by-products as a primary source of the bioactive resin acids that are integrated into the current uses of these species.
... Our results are comparable with those of other authors for E. globulus stemwood as well as for other eucalypt species. Santos et al. (2017) focused on E. grandis wood from Portugal, Brazil, and South Africa, which was obtained as the main family sterol, followed by fatty acids, while triterpenic acids were detected only in Brazilian wood. According to Domingues et al. (2010), studying the DCM extracts from eucalypt residues found predominantly triterpenoids and fatty acids type of compounds as mentioned here. ...
... Regarding the DPPH method, both heartwood and sapwood ethanol extracts displayed strong antioxidant activity, with AAI values exceeding 2. Heartwood ranged from 9.2 to 18.3, while sapwood ranged from 7.9 to (2015), while testing several methods to obtain phenolic compounds from E. globulus wood wastes, showed that ethanol was the best solvent compared to water or methanol to yield more compounds with high antioxidant properties. Santos et al. (2017), while studying E. grandis wood obtained differences in antioxidant activities of the phenolic extracts regarding the geographic origin: Brazil wood had the highest antioxidant activities, followed by South African and Portugal (IC50 of 5.08, 6.13 and 6.18 µg/mL). ...
Eucalyptus globulus stumps are a by-product from the coppice pulp plantation after three generations. In this study a stump was fractionated in three discs (60 cm between them), and their constituent tissues—heartwood, sapwood and bark—were subjected to further chemical characterization by summative analysis, evaluation of the phytochemical profile and antioxidants activities, plus GC/MS and analytical pyrolysis aiming at their valorization. Wood density was similar between tissues and disc level: values ranging from 0.652 to 0.705 g/cm³ (Disc 1) and 0.605 g/cm³ (Disc 5). Bark had high ash (3.5%), extractives (7.5%) and holocellulose (68.4%) but lower lignin contents (22.0%). Original heartwood contained 0.7% ash, 7.0% extractives, 27.1% lignin, and 67.3% holocellulose. Heartwood showed high extractives (12.1–15.8%), less lignin (23.9–24.5%), and high holocellulose (61.7–64.7%) compared to sapwood which contained 3.9–5.4% extractives, 26.9–27.3% lignin and 68.6–71.5% holocellulose. Water extracts had poor antioxidant activity in contrast to ethanol extracts with high activities in heartwood. All tissues presented GS lignin type with S/G ratios varying from 3.0 to 3.4 (heartwood), 3.2–3.4 (sapwood), bark (3.5) and 3.8 (original heartwood). In wood, fibers and vessels were highly lignified with SG and G-lignin respectively; while rays had low lignin with G-type. Light and fluorescence macroscopic observation of the tissues in Disc 1 revealed a lower proportion and larger vessels in sapwood and high emission fluorescence at 488nm. Overall, these results show that stumps are valuable raw material to be used under the biorefinery context.
... The total phenolic content (TPC) of the Pinus spp. barks was evaluated using the Folin-Ciocalteu reagent, following a previously described procedure [23,26], with some adaptations [21]. The TPC was determined through a standard curve of gallic acid (5-100 µg mL −1 ) and expressed as mg of gallic acid equivalents (GAE) per g of extract and g GAE per kg of dw. ...
... The ABTS radical cation (ABTS •+ ) scavenging activity of the Pinus spp. bark extracts was measured according to a described procedure [23,32] and adapted to the 96-well plate scale. Firstly, stock solutions (1 mg mL −1 ) of three bark polar extracts from each Pinus species were prepared in methanol/water (50:50, v/v). ...
Agroforestry by-products have gained rising attention in recent years as they represent inexpensive and abundant raw materials that are a source of added-value chemicals, e.g., for food and pharmaceutical applications, as well as for bioenergy generation. Pinus pinaster Ait. bark extracts are consumed worldwide for their cardiovascular benefits, whilst the health potential of Pinus pinea L. bark has not yet been deeply exploited. Therefore, this study highlights the chemical characterisation of Portuguese P. pinaster Ait. and P. pinea L. bark polar extracts, via ultra-high performance liquid chromatography-diode array detection-tandem mass spectrometry (UHPLC-DAD-MSⁿ) analysis, and their antioxidant and antibacterial activities. Quinic acid, an A-type procyanidin dimer isomer, protocatechuic acid, and quercetin were identified for the first time as P. pinea L. bark components. Moreover, this bark demonstrated a higher total content of identified polar compounds than P. pinaster Ait. bark, with quinic acid being the most abundant compound identified. Regarding antioxidant activity, the pine bark polar extracts exhibited strong reducing power and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis-(3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) radical scavenging effects compared to natural antioxidants. Moreover, the bactericidal actions of pine bark extracts were shown against Staphylococcus aureus and Escherichia coli at a 3.13–25 mg mL⁻¹ range. Globally, these promising insights can boost the sustainable exploitation of P. pinea L. bark, as already occurs with P. pinaster Ait. bark, for the food and biomedical fields.
... However, one recent study identified β-sitosterol (Figure 1d Figure 1i) in E. grandis wood. 29 Phytochemical evaluations of the other parts of this species are less extensive and much further work is required. Many of these compounds have been reported to have potent antibacterial activity 30 and may therefore contribute to the antibacterial properties of E. grandis. ...
... E. grandis (a) whole plant, (b) leaves and flowers, (c) fruit and some compounds identified in E. grandis: (d) β-sitosterol, (e) syringaldehyde, (f ) catechin, (g) proanthocyanidin dimer, (h) ellagic acid and (i) ellagic acli-O-pentoside.29 ...
Introduction: Closely related plant species often share similar secondary metabolites and bioactivities and are therefore good targets for bioactivity testing when one or more species within a genus are known to possess therapeutic properties. The genus Eucalyptus has a long history of medicinal usage by the first Australians. Many species are known to have therapeutic properties, several species of which have well established antibacterial bioactivities. Methods: The ability of Eucalyptus grandis leaf and flower extracts to inhibit the growth of a panel of bacterial and fungal pathogens was investigated by disc diffusion assay. Toxicity was examined using the Artemia franciscana nauplii bioassay. Results: E. grandis leaf and flower methanolic and aqueous extracts were completely ineffective at inhibiting the growth of gram-positive and gram-negative panels of bacteria, as well as fungi. The extracts were nontoxic in the Artemia nauplii bioassay following 24 hr exposure. Conclusion: Despite the taxonomic relationship to several bioactive Eucalyptus spp., E. grandis leaf and flower extracts
... Conforme Santos et al (2017), apesar do Eucalipto ser uma planta nativa da Austrália, trata-se de um dos cultivos florestais mais difundidos, especialmente por companhias de papel e celulose, justamente pela adaptabilidade à diferentes condições climáticas, pelo rápido crescimento observado e pelas excelentes propriedades da madeira do eucalipto. Seu impacto econômico em escala mundial é, portanto, significativo. ...
... Seu impacto econômico em escala mundial é, portanto, significativo. Santos et al (2017) ainda ressalta que apesar das preocupações ambientais que cercam tal espécime, a alta incidência das florestas de Eucalipto contribui para diminuir as pressões sobre as indústrias, uma vez que esse cultivo substitui naturalmente as florestas tropicais, comprometendo a biodiversidade notória destas. ...
O uso de materiais suplementares em concretos e argamassas de cimento Portland vem se tornando crescente devido aos danos ambientais que a produção de cimento e a extração de agregados naturais podem causar ao meio ambiente. O objetivo deste artigo é avaliar a eficiência da cinza de madeira de eucalipto (CME) como substituto parcial do agregado miúdo em argamassas de cimento Portland, almejando reduzir a quantidade de agregados naturais e dar uma destinação correta à um resíduo industrial. Para isso foram fabricados corpos de prova (CPs) de argamassas com substituição de 0% (controle), 10%, 20%, 30%, 40% e 50% de CME pelo agregado miúdo, mantendo constante em todos os traços a quantidade de cimento e água/cimento (a/c). Os CPs foram ensaiados à compressão axial, à consistência e à absorção de água. Observou-se um acréscimo na resistência à compressão axial, comparando-se ao controle, com o aumento da porcentagem de substituição até 30% de CME, enquanto que a fluidez diminuiu com o aumento de CME em todas as amostras, diminuindo a trabalhabilidade. Da mesma forma, a absorção de água diminui com o aumento de CME nas misturas, melhorando a compacidade das misturas. Pode-se concluir com base nos resultados apresentados que o uso de CME até 30% em substituição ao agregado miúdo é interessante, sendo esta a porcentagem ideal, pois agrega os melhores resultados de resistência à compressão das argamassas, com trabalhabilidade aceitável e redução da absorção de água. A utilização desse material também colabora para a redução dos danos ambientais.PALAVRAS-CHAVE: Danos ambientais. Materiais suplementares. Cinza de madeira de eucalipto.
... As a large group of tree species native to Australia, Papua New Guinea and the Philippines [12,13], Eucalyptus has been introduced around the world over the past century and has become one of the most important artificial commercial forest species providing a large amount of wood for industrial production and sufficient raw material for pulp and paper production [14]. At present from a global perspective, most countries, including China [10,15,16], Brazil [17][18][19], South Africa [20,21], Australia [22,23], etc., mainly use E. grandis × E. urophylla or its backcross hybrids for afforestation to take advantage of heterosis. It should be noted that E. grandis is a widely used hybrid parent, and the effective evaluation, protection and utilization of the germplasm resources of E. grandis are the premise and foundation for further inter-and intraspecific hybrid breeding based on the multigeneration breeding strategy for these tree species [10,15,[24][25][26][27]. ...
Background
Eucalyptus grandis, which was first comprehensively and systematically introduced to China in the 1980s, is one of the most important fast-growing tree species in the forestry industry. However, to date, no core collection has been selected from the germplasm resources of E. grandis based on growth and genetic relationship analysis.
Results
In the present study, 545 individuals of E. grandis collected from 28 populations across 5 countries were selected for genetic diversity analysis using 16 selected SSR markers. The polymorphism information content (PIC) was employed to assess genetic diversity, yielding a mean value of 0.707. Genetic structure analysis was conducted on 492 individuals from 13 combined populations, revealing three clusters as the most suitable number. Principal coordinate analysis (PCoA) demonstrated that the populations were divided into three major clusters. Additionally, the analysis of molecular variance (AMOVA) indicated that the majority of variation occurred within populations.
Conclusions
Based on the criteria for screening the core collection, we constructed a population consisting of 158 individuals and created unique fingerprinting codes. These results provide a crucial theoretical foundation for the protection and utilization of germplasm resources of E. grandis in China, which will be helpful in the selection of genetically distant parents for future multigenerational hybridization programs.
... These phytochemicals include triterpenic acids, such as ursolic (1), betulinic (2) and oleanolic acids (3) (Domingues et al., 2011a;Domingues et al., 2011b), epicatechin (4) and quercetin-glucuronide (5) (Santos et al., 2012). The E. grandis wood consists of hexadecanoic (6) and 9,12-octadecadienoic acids (7), b-sitosterol (8) and stigmasterol (9) (Santos et al., 2017). ...
The genus Eucalyptus has attracted considerable attention from natural product specialists exploring new phytochemicals for therapeutic purposes due to their possible biological activities. This was stimulated by current findings that Eucalyptus species interrupt the propagation of the recently tormenting COVID-19 virus. Eleven Eucalyptus leaf extracts were subjected to in vitro antimicrobial studies against four bacterial strains: Staphylococcus aureus, Streptococcus pyogenes, Staphylococcus lugdunensis and Staphylococcus epider-mis using the broth serial dilution assay. The potential of the extracts to inhibit free radicals 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2 0-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) was investigated, indicating antioxidant properties. Furthermore, the cytotoxicity test was performed against the human embryonic kidney (HEK293-T) cell line using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Phytochemicals were identified and characterized using Fourier transform infrared spec-troscopy (FTIR) and one-dimensional gas chromatography mass spectrometry (GCÀMS). Moreover, the microwave plasma atomic emission spectroscopy (MP-AES) coupled with inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to evaluate the multielemental composition of the extracts. The MP-AES and ICP-OES techniques in this work displayed accuracy and sensitivity for multielement determination by identifying P, B, Ca, Zn, Cu, Mg, Fe, Mn, Na, and K as major constituents in Eucalyptus extracts. The extracts generally had strong antioxidant and antibacterial properties, with E. viminalis (IC 50 = 2.91 § 0.22 mg/mL) demonstrating strong action against the ABTS radical. E. nitens and E. dunnii also showed highest activity against DPPH and ABTS, with IC 50 values < 10 mg/mL. Additionally, with IC 50 values greater than 20 mg/mL, the extracts demonstrated relative non-toxicity against HEK293-T cells. The existence of the bioactive chemicals found by FTIR and GCÀMS may be the cause of the observed biological activity. Because Eucalyptus plant species have the highest antioxidant activity and the most inhibitory action against the majority of Streptococcus bacterial strains, they can be employed as a therapeutic treatment to treat infections caused by Streptococcus.
... The observed increase in H 2 O 2 concentrations only in plants with lime application and MDA concentration, resulting from lime × CZF, suggests that these factors influence the oxidation of plant cells, potentially causing damage to DNA, lipids, and other secondary metabolites (Pizzaia et al., 2019;Santos et al., 2017). The overproduction of H 2 O 2 leads to the oxidation of the plant cell's lipid phosphate layer, thereby promoting senescence and cell death (Baxter et al., 2014;Noctor et al., 2016). ...
... 21 Ellagic acid (EA) is a polyphenolic compound found in some types of fruit, such as strawberries, blueberries, and pomegranates. 22 Pomegranate fruit extract (PFE) shows antioxidative activity caused by the action of EA. 23 Research findings show that EA is a potential biomolecule with remarkable biological features, such as UV shielding and anticancer functionalities. 24−26 It is also a potent antioxidant and antibacterial agent. ...
The polyphenol compound ellagic acid (EA) extracted from pomegranate has potential bioactivity against different types of chronic diseases. Skin aging is a long-term physiological process caused by many environmental factors, the most important of which is exposure to sun ultraviolet (UV) radiation. UV-induced chronic photodamage of the skin results in extrinsic aging. This study aimed to evaluate the photoprotective effects of EA on the human fibroblast skin cell line HFB4 and investigate its capacity to protect collagen from UV-induced deterioration. EA was encapsulated into chitosan-coated niosomes to reduce the skin aging effect of UV radiation in vitro. The tested formulations (niosomes loaded with EA and chitosan-coated niosomes loaded with EA) were characterized using transmission electron microscopy, dynamic light scattering, and scanning electron microscopy. Furthermore, the in vitro release of EA was determined. The HFB4 cell line samples were split into five groups: control, UV, UV-EA, UV-NIO-EA, and UV-CS-NIO-EA. UV irradiation was applied to the cell line groups via a UV-emitting lamp for 1 h, and then cell viability was measured for each group. The expression of genes implicated in skin aging (Co1A1, TERT, Timp3, and MMP3) was also assessed to quantify the impact of the loaded EA. The findings showed that EA-loaded chitosan-coated niosomes improved cell survival, upregulated Col1A1, TERT, and Timp3 genes, and downregulated MMP3. Thus, nanoparticles encapsulating EA are potent antioxidants that can preserve collagen levels and slow down the aging process in human skin.
... As such, genetic investigations have focused on early responses to cultivation (Jones et al., 2006;Bouffier et al., 2008;Varghese et al., 2009;De La Torre et al., 2014;Skrøppa & Steffenrem, 2016) or genomic responses to natural selection (Prunier et al., 2011; Cultivation of E. grandis as a timber and wood fibre crop has been ongoing for over 100 yr in various exotic environments around the world (Bennett, 2011). From its origins in Australia, the species has been transplanted to every continent except Antarctica (Marco, 1991;Rockwood & Meskimen, 1991;Huoran et al., 1992;Chaix et al., 2003;Hunde et al., 2003;Dos Santos et al., 2004;Verryn et al., 2009;Luo et al., 2010;Boulay et al., 2012;Santos et al., 2017). Its fast growth has been further improved in exotic breeding programmes where artificial selection resulted in trees reaching harvestable age 10-15% earlier (Verryn, 2002), and produced increases of 16% in stem volume per generation of breeding (Meskimen, 1983). ...
From its origins in Australia, Eucalyptus grandis has spread to every continent, except Antarctica, as a wood crop. It has been cultivated and bred for over 100 yr in places such as South Africa. Unlike most annual crops and fruit trees, domestication of E. grandis is still in its infancy, representing a unique opportunity to interrogate the genomic consequences of artificial selection early in the domestication process.
To determine how a century of artificial selection has changed the genome of E. grandis, we generated single nucleotide polymorphism genotypes for 1080 individuals from three advanced South African breeding programmes using the EUChip60K chip, and investigated population structure and genome‐wide differentiation patterns relative to wild progenitors.
Breeding and wild populations appeared genetically distinct. We found genomic evidence of evolutionary processes known to have occurred in other plant domesticates, including interspecific introgression and intraspecific infusion from wild material. Furthermore, we found genomic regions with increased linkage disequilibrium and genetic differentiation, putatively representing early soft sweeps of selection.
This is, to our knowledge, the first study of genomic signatures of domestication in a timber species looking beyond the first few generations of cultivation. Our findings highlight the importance of intra‐ and interspecific hybridization during early domestication.
... It looks, however, that the composition of eucalyptus barks have not yet been thoroughly analysed for different substances, although for example various phenolic compounds, tannins, and triterpene acids are frequently found. Although these seem to include various bioactive components potential for both food and pharmaceutical applications 316 , their concentrations tend to be quite low, thus hindering commercial uses so far. In any case, it would be justified to conduct further studies on the composition of the local eucalyptus bark materials for their potential use by the local pharmaceutical companies, for example. ...
This VTT Technology report on 'The Future of Forest-based Bioeconomy Areas: Strategic openings in Uruguay and the World by 2050' is the result of a multistakeholder and multi-disciplinary foresight exercise commissioned by the Government of Uruguay in 2018 and completed in 2019. The overall goal of the project was to contribute to Uruguay's National Development Strategy 2050 through the following specific objectives: (1) To identify key global forest-based bioeconomy areas by 2050; (2) To identify needs and gaps in the prioritised FBA in Uruguay; (3) To develop a shared vision for the forest-based bioeconomy in Uruguay by 2050; and (4) To develop a strategic Action Roadmap to achieve the shared vision for the forest-based bioeconomy in Uruguay by 2050.
The most important outcomes of the project include: a shared vision for key foresight-based bioeconomy areas (FBAs), as well as five consolidated Action Roadmaps with 511 concrete short-medium-to-long-term actions related to Forest management (FBA1), Mechanical wood processing (FBA2), Fibre-based biomaterial processing (FBA3), Biorefining (FBA4), and Bioenergy (FBA5). In addition, the report provides more detailed recommendations addressing a wide range of research, education, innovation and institutional needs related to the Top 3 Opportunity Pathways (OPs) of the five FBAs. The methodology of the project involved systematic critical issues analysis (drivers, barriers, threats and opportunities), a multi-stakeholder Delphi-like survey, global value network and business news analysis, visioning workshops and action roadmapping.
This report is valuable for government, business, research and civil society actors interested in the state-of-the-art and the future of key forest-based bioeconomy areas in the world. Foresight researchers and practitioners will also find interesting methodological approaches, such as the consolidated action roadmaps.
Finally, taking worldview perspective, while the project provided an opportunity for foresight knowledge transfer from Europe to Latin America, both the findings and methodology are equally relevant for other world regions and countries concerned with the future of the forest-based bioeconomy.
... There is a clear need for green technologies to extract triterpenoids for application as nutraceuticals and pharmaceutical ingredients, due to the increasing evidence on the bioactivities of these compounds and the concern about the environmental impact of use and disposal of organic solvents. Moreover, this is a general issue for terpenic compounds [10,11]. Sustainable processing methods of plant materials have been a topic of growing interest in recent years. ...
Triterpenoids are among the bioactive components of Chaga, the sterile conk of the medicinal fungus Inonotus obliquus. Supercritical fluid extraction of Chaga triterpenoids was carried out with supercritical CO2, while a modified Folch method was used as a comparison. Three temperature-pressure combinations were tested varying between 314–324 K (40–50 °C) and 281–350 bars, using time- and volume-limited extractions. Six triterpenoids were identified with GC-MS and quantified with GC-FID: ergosterol, lanosterol, β-sitosterol, stigmastanol, betulin, and inotodiol. The Folch extraction resulted in recovery of trametenolic acid, which was not extracted by supercritical CO2. Inotodiol was the major triterpenoid of all the extracts, with a yield of 87–101 mg/100 g and 139 mg/100 g, for SFEs and the Folch method, respectively. The contents of other major triterpenoids, lanosterol and ergosterol, varied in the ranges 59–63 mg/100 g and 17–18 mg/100 g by SFE, respectively. With the Folch method, the yields were 81 mg/100 g and 40 mg/100 g, respectively. The highest recovery of triterpenoids with SFE in relation to Folch was 56% and it was obtained at 324 K (50 °C) and 350 bar, regardless of extraction time or volume of CO2. The recoveries of lanosterol and stigmastanol were unaffected by SFE conditions. Despite the lower yield, SFE showed several advantages including shorter extraction time and less impact on the environment. This work could be a starting point for further studies on green extraction methods of bioactive triterpenoids from Chaga.
... Some tree species have a particularly high EA content in wood and bark, such as Quercus spp., Eucalyptus spp., and Castanea spp. [154][155][156][157]. Consequently, by-products of the forestry and wood-processing industries (as well as byproducts of juice production such as pomegranate husk) are a potential source of industrial production for EA [149]. ...
Ellagic acid (EA) is a bioactive polyphenolic compound naturally occurring as secondary metabolite in many plant taxa. EA content is considerable in pomegranate (Punica granatum L.) and in wood and bark of some tree species. Structurally, EA is a dilactone of hexahydroxydiphenic acid (HHDP), a dimeric gallic acid derivative, produced mainly by hydrolysis of ellagitannins, a widely distributed group of secondary metabolites. EA is attracting attention due to its antioxidant, anti-inflammatory, antimutagenic, and antiproliferative properties. EA displayed pharmacological effects in various in vitro and in vivo model systems. Furthermore, EA has also been well documented for its antiallergic, antiatherosclerotic, cardioprotective, hepatoprotective, nephroprotective, and neuroprotective properties. This review reports on the health-promoting effects of EA, along with possible mechanisms of its action in maintaining the health status, by summarizing the literature related to the therapeutic potential of this polyphenolic in the treatment of several human diseases.
... An additional supply of Cu and Zn fertilizers modified the activity of several antioxidant enzymes in eucalyptus trees (Fig. 3). In the presence of oxygen (O 2 ), the metallic micronutrients (e.g., Cu and Zn) catalyze the redox cycling of phenolic compounds, thus contributing to combat the production of ROS and other organic radicals, which can damage DNA, lipids, and other secondary metabolites (Pizzaia et al., 2019;Sakihama et al., 2002;Santos et al., 2017Santos et al., , 2012. Indeed, the modulation of antioxidant machinery is crucial for plants to cope with challenging environments (Soares et al., 2019). ...
The Eucalyptus grandis L. plantations for industrial purposes (e.g., wood charcoal and pulp) are largely adopted worldwide, mainly in acidic and poorly fertile soils. The application of lime to soil is recommended for eucalyptus plantation, but lime reduces the availability of metallic micronutrients to plants. Therefore, the aim of this study was to investigate the performance of field-grown Eucalyptus grandis in Ferralsol amended with lime at different rates (0.0 and 1.6 and 3.7 Mg ha-1) and Cu plus Zn [0.0 and 0.0 kg ha-1 (-CuZn) and 0.5 and 1.5 kg ha-1 (+CuZn)]. The soil chemical attributes, shoot biomass, and nutrient accumulation were evaluated, while nutrient use efficiency, chlorophyll (Chl) and flavonoid (Flav) contents, and enzymatic antioxidant performance [superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), ascorbate peroxidase (APX), guaiacol peroxidase (GPOX), and glutathione peroxidase (GPX)] were assayed to assess the nutritional status of the plants. Despite the lime application rate increasing Ca and Mg soil availabilities, effective cation exchange capacity (eCEC), base saturation (BS), and pH values, the available Cu, Fe, and Zn concentrations decreased at 6 and 30 months after planting. Conversely, Mn soil availability increased with lime application rates. Liming augmented Cu-, Fe-, Mn-, and Zn-use efficiency, while +CuZn supply increased enzymatic antioxidant performance in 30-month-old plant. Overall, the combined application of lime and +CuZn enhanced shoot biomass relative to that of non-treated plants. However, there was no observed difference in shoot biomass in 30-month-old limed and non-limed eucalyptus trees that were supplied with +CuZn. This result can be partially explained by the improvement in soil chemical attributes, such as soil pH, eCEC, and BS. In conclusion, the use of integrative approaches and temporal evaluations provided new insights into wood yield, biochemical traits, antioxidant metabolism, and the nutritional status of field-grown eucalyptus under lime and +CuZn application rates.
... Flavonoids are some of the most active substances in Prunus mume blossoms. As a natural product mainly found in plants, flavonoids have many important physiological and biochemical effects due to their unique chemical structure [2]. The active ingredients of many traditional Chinese medicinal materials are flavonoids [3,4]. ...
Prunus mume blossom is an edible flower that has been used in traditional Chinese medicine for thousands of years. Flavonoids are one of the most active substances in Prunus mume blossoms. The optimal ultrasonic-assisted enzymatic extraction of flavonoids from Prunus mume blossom (FPMB), the components of FPMB, and its protective effect on injured cardiomyocytes were investigated in this study. According to our results, the optimal extraction process for FPMB is as follows: cellulase at 2.0%, ultrasonic power at 300 W, ultrasonic enzymolysis for 30 min, and an enzymolysis temperature of 40 °C. FPMB significantly promoted the survival rate of cardiomyocytes and reduced the concentration of reactive oxygen species (ROS). FPMB also improved the activities of proteases caspase-3, caspase-8, and caspase-9 in cardiomyocytes. The cardiomyocyte apoptosis rate in mice was significantly reduced by exposure to FPMB. These results suggest that the extraction rate of FPMB may be improved by an ultrasonic-assisted enzymatic method. FPMB has a protective effect on the injured cardiomyocytes.
... According to Várhegyi et al. (2004), the removal of some extractives decreases the fixed carbon content, reducing the charcoal yield and shifting the thermo-gravimetric curve to higher temperatures. However, the extracts contained in the wood of forest species may have potential for nutraceutical applications (Santos et al. 2017), as antioxidants (Cetera et al. 2019) and antifungal/antimicrobial agents (Lovaglio et al. 2017). Thus, investigating the role of wood extractives is critical for many industrial applications. ...
The aim of this study was to evaluate the performance of multivariate models using Near infrared (NIR) spectra for predicting total extractives content of solid and powdered wood of planted and native species from tropical savanna. NIR spectra were recorded on the milled wood and radial surface of solid wood specimens of Cedrela sp., Jacaranda sp., Apuleia sp., Aspidosperma sp. and clones of Eucalyptus hybrids via an integrating sphere and fiber optics probe. NIR spectral signatures were evaluated by Principal Component Analysis (PCA) and then associated to the total extractive content quantified by extraction in toluene/ethanol (2:1) solutions, pure ethanol and hot water by Partial Least Squares (PLS) regressions. PCA revealed that NIR spectra measured in solid wood by integrating sphere gave a better discrimination of wood species. A global PLS model was developed based on NIR obtained by integrating sphere with satisfactory estimations both for solid wood (R²cv= 0.87, RMSECV= 1.08%) and wood powder (R²cv= 0.85, RMSECV= 1.19%). An independent test-set validation was performed with 25% of the samples and yielded R²p= 0.93 and RM-SEP= 0.95% (for solid wood) and R²p= 0.87 and RMSEP= 1.40% (for wood powder). Both models can be applied for rapid screenings, though models developed from NIR spectra by integrating sphere on solid wood are considered more suitable for rapid predictions of extractive content in unknown wood specimens.
... Although the extractives of wood and bark are usually considered minor components, they are believed to play an important role. Recent studies were focused on the characterization of bark extractives [4][5] and the antioxidant properties of the bioactive compounds from Eucalyptus [6][7], Cameroonian woods [8] and other wood species. ...
... In addition, phytochemical analysis in plants confirms the presence of alkaloids, steroids, flavonoids, coumarin, saponins, glycosides and phenols (Gröcer et al., 1998). The studies about wood extractives have been stimulated in the discovery and characterization of new chemical structures, taxonomic classification of species, tree growth processes, obtaining of new products and by-products of commercial value and the determination of problems related to some uses of wood (Santos et al., 2017;Barbosa et al., 2005;Klock et al., 2005). ...
This work aimed to investigate phytochemical prospection in treated and untreated wood of Eucalyptus grandis to understand the dynamics of extractives in relation to heat treatment. Samples of E. grandis wood were collected and grouped into external and internal regions. Half of the samples from each region were submitted to heat treatment at 190 ºC. From the treated and untreated samples, phytochemical tests were performed to detect classes of metabolites present in the E. grandis raw wood, hydrophilic extract and lipophilic extract. Phytochemical analysis detected the presence of alkaloids, phenolic compounds and triterpenoids in all hydrophilic extracts of the studied species. Presence of flavanonols, flavanones and saponins was detected only in the internal region of the wood. Tannins, leucoanthocyanidins, triterpenoids and saponins were influenced by heat treatment. The classes of flavonoids, xanthones and alkaloids are the most resistant to heat treatment. The phytochemical analysis made it possible to identify a new class of extractives that emerged after heat treatment, flavones.
... Radical scavenging activity of samples was evaluated by spectrophotometry by monitoring the decrease of absorbance at 517 nm of methanolic solution of the radical DPPH (2,2-diphenyl-1-picrylhydrazyl) incubated for 30 min in the darkness in the absence or in the presence of plant extracts [25,26]. The DPPH solution was diluted with methanol/water mixture 7:3 (v/v) to give an absorbance of the negative control (0.9 ± 0.05) at 517 nm. ...
The study examines the phenolic compounds in hydromethanolic extracts of Salix alba (L.) leaves and bark as well as their antioxidant activity and cytotoxic potential. UPLC-PDA-Q/TOF-MS analysis showed a total of 29 phenolic compounds in leaves and 34 in bark. Total phenolic compound content was 5575.96 mg/100 g of dry weight (DW) in leaves and 2330.31 mg/100 g DW in bark. The compounds were identified as derivatives of phenolic acids (seven in leaves and five in bark), flavanols and procyanidins (eight in leaves and 26 in bark) and flavonols (14 in leaves and three in bark). Both extracts exhibited strong antioxidant potential, assessed by radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), but the bark extract was even stronger than the ascorbic acid used as a standard. The cytotoxicity of both extracts was evaluated against human skin fibroblasts and human epidermal keratinocytes cell lines using the Presto Blue cell viability assay. The keratinocytes were more resistant to tested extracts than fibroblasts. The leaf and bark extracts at concentrations which exhibited antioxidant activity were also not toxic against the keratinocyte cell line. Thus, S. alba extracts, especially the leaf extract, offer promise as a nontoxic natural antioxidant, in cosmetic products or herbal medicines, and as a source of bioactive secondary metabolites.
... Therefore, EA is also present in agro-forest and industrial residues (e.g., in cork, tree bark and wood) [46]. In fact, Santos and co-workers [47] reported 512.8 mg·kg −1 (dw) of EA in Brazilian E. grandis and these values are in accordance with their previous findings. Moreover, using the capillary zone electrophoresis (CZE) analytical procedure, reliable determinations have been made of EA in E. globulus wood: 1100 ± 600 mg·kg −1 (dw) [48]. ...
Ellagitannins (ETs), characterized by their diversity and chemical complexity, belong to the class of hydrolysable tannins that, via hydrolysis under acidic or alkaline conditions, can yield ellagic acid (EA). They are mostly found as a part of extractives in angiosperms. As known antioxidants and chelators, EA and EA derivatives are drawing an increasing interest towards extensive technical and biomedical applications. The latter ones include possible antibacterial, antifungal, antiviral, anti-inflammatory, hepato- and cardioprotective, chemopreventive, neuroprotective, anti-diabetic, gastroprotective, antihyperlipidemic, and antidepressant-like activities, among others. EA’s synthesis and production challenges prompt further research on new methods and alternative sources. Conventional and prospective methods and raw materials for the production of EA and its derivatives are reviewed. Among the potential sources of EA, the residues and industrial streams of the pulp industry have been highlighted and considered as an alluring alternative in terms of commercial exploitation.
... A high degree of variation has been visually observed among the obtained results and was further confirmed via the statistical analyses. Such disparity is in accord with the literature since Eucalyptus was reported to contain a range of secondary metabolites that can vary greatly between and within species [50]. When we compared the contents of secondary metabolites among Eucalyptus species, it has been shown that E. camaldulensis is a superior species due to its richness with total phenolics, tannins, flavonoids and total antioxidant potentials (phosphomolybednum assay). ...
Background
Eucalyptus belongs to the Myrtaceae family; it is the most planted hardwood forest crop worldwide, representing a global renewable resource of fiber, pharmaceuticals and energy.
Objective
Comparing among five species; E. maidenii, E. robusta, E. citriodora, E. tereticornis and E. camaldulensis, seeking for the richest source of nutrients and pharmaceuticals.
Methodology:
Eucalyptus samples were subjected to some chemical determinations for both primary and secondary metabolites to verify their nutritional and pharmaceutical importance related to different extracts. GC-MS analysis was applied to detect the presence of some individual phenolic constituents in their leaves.
Results
E. robusta recorded the maximum contents of carbohydrates (46.13%) and protein (31.91%). While, E. camaldulensis contained the highest contents of total phenolic compounds (46.56 mg/g), tannins (40.01 mg/g) and antioxidant activities assayed by phosphomolybednum method (57.60 mg/g), and followed by E. citridora. However, E. tereticornis exhibited the highest reducing power ability (151.23 mg/g). The GC-MS highlighted 20 phenolic constituents and antioxidants which varied in their abundance in leaves of Eucalyptus species, 8 individual phenolics (hydroquinone, hesperitin, pyrogallol, resorcinol, protocatechuic acid, naringenin, chlorogenic acid and catechin) were maximally recorded with E. camaldulensis and secondly with E. citridora in case of at least 5 components. Nevertheless, gallic and quinic acids were more abundant in the leaves of E. tereticornis, which may explain its high corresponding reducing powers.
Conclusion
Acetone-water combination has enhanced the phenolics extraction from Eucalyptus tissues. This is the first report aiming to compare between the aforementioned Eucalyptus species highlighting either their nutritional or medicinal importance.
... The relation between phenols accumulation and shoot development is well established (Schwalb and Feucht, 1999); herein total phenols in annual shoots (except for xylem) ranged from 22 to 32 g kg −1 DW (Supplementary Table 3), which is ten to fifteen fold-change higher concentration than those previously detected in Eucalyptus wood (Santos et al., 2017). The concurrent shoot-specific depletion and budspecific accumulation in peonidin-3-O-gal (Figs. ...
Few studies have focused on the metabolic characterization of bud dormancy and shoot growth in temperate fruit species, although this is an intresting framework to anticipate adaptation in global climate changes. To examine this issue, two experimental approaches were applied, using sweet cherry (Prunus avium L. cv ‘Grace Star’) bud and shoot tissues. Initially, annual shoots containing vegetative buds that collected at endodormancy and ecodormancy stages were used to compare changes in shoots- and buds-specific metabolic profiles under chamber-controlled conditions. Detailed analysis suggested that primary metabolites, such as arabitol, fucitol and tryptophan were modified in buds from endo- to eco-dormancy. Differences between buds and shoots metabolic fingerprints were also found in various secondary metabolites, including quercetin, glucosides and osmotic-associated metabolites. In order to investigate the mechanism underlying shoot developmental during bud dormancy break, metabolic analysis was also conducted in annual shoots, that were sampled at five distinct bud-related vegetative stages from ecodormancy to fully developed leaf stage under natural orchard conditions. Several amino acids (ornithine, alanine, isoleucine, GABA, asparagine and tryptophan) and classes of secondary metabolites, including anthocyanidins (peonidin-3-O-galactoside), flavonoids (apigenin, isorhamnetin, chrysin and trilobatin) and lignin-related compounds (sinapyl and coniferyl alcohols) were altered across developmental stages. Additionally, nutrient homeostasis was altered during shoot development, as N, P, Ca, Mg, B steady-state level as well as Ca/Mg + K and N/P stoichiometry were significantly changed. This study provides a bud- and shoot-based metabolic framework at different conditions and dormancy stages, thereby helps to understand dormancy release and bud-break in temperate fruit trees.
... Several researchers showed how different biomass sources could provide interesting results to exploit the economic and industrial potential of the biomass refinery. In this sense several recent studies were focused on the characterization of bark extractives (Hofmann et al., 2015;Rosdiana et al., 2017) and the antioxidant properties of the bioactive compounds from Eucalyptus (Luís et al., 2016;Santos et al., 2017) or Cameroonian woods (Saha et al., 2013). ...
A renewed interest in producing thermo-treated wood extracts and the potential applications of these extracts was observed in chemical, pharmaceutical, and food industries. Poplar (Populus spp.), belonging to the Salicaceae family, is one of the most cultivated woody plant for industrial purposes, one of the least expensive hardwoods, rarely used in the production of fine furniture, but extensively used for pulp and panel productions and have therefore an important economic impact worldwide. The aim of this study was to verify the influence of thermo-vacuum treatment (at 180, 200, and 220 °C) on wood extracts obtained via three different extraction techniques: maceration, ultrasound-assisted extraction and accelerated-solvent extraction. Effect of temperature on extraction was verified by measuring the total contents of polyphenols, tannins and flavonoids. Secondary metabolites are often related to antioxidant activity measured by several in vitro tests, including the 2,2-diphenyl-1-picrylhydrazyl radical-scavenging method, the ferric-reducing-ability power test, and the beta-carotene bleaching assay. Our results showed the presence and the effect of heat treatments and extraction techniques on polyphenol and flavonoid contents. Extracts obtained from wood heated at 200 and 220 °C showed the highest flavonoid and polyphenol contents, and, we observed a relationship with the shown antioxidant activity levels. Our study clearly showed the differential effects of temperature and extraction technique on both antioxidant activity and secondary metabolite contents. The detailed knowledge about the extractives from poplar wood can contribute, on the one hand, to better understand the effect of temperature during thermo treatment, and, on the other demonstrates the potential of this species as a source of bioactive compounds for nutraceutical or pharmaceutical applications by identifying appropriate extraction techniques.
... Among the multitude of active agents, ellagic acid (EA), a polyphenolic compound abundant in some fruits, nuts and seeds (Landete, 2011), but also on agro-forest and industrial residues (e.g., cork, tree bark and wood) (Santos et al., 2017), seems a promising biomolecule with interesting biological activities, including antioxidant activity, antibacterial activity, UV-barrier properties, just to mention a few examples (Landete, 2011). Our interest in CH and EA stems from the idea of merging the antimicrobial properties of CH with the antioxidant and UV-barrier properties of EA in order to obtain bioactive films with UV-light protection. ...
Homogeneous, translucent and flexible films of chitosan (CH) and ellagic acid (EA) were prepared by solvent casting. Various concentrations of EA (0.5, 1.0, 2.5 and 5.0% w/w relative to CH) were used in order to evaluate their UV-blocking properties. In addition, the photochemical stability of the films was also studied via artificial solar light irradiation. These set of films display high mechanical properties (Young’s modulus = 3.21–3.57 GPa), thermal stability up to 215–220 °C, UVA- and UVB-barrier properties, moderate water vapor permeability (WVP = 2.82–3.70 g mm m⁻² day⁻¹ kPa⁻¹) and maximum antioxidant activity around 28% (DPPH scavenging activity). Furthermore, all CH/EA films show antimicrobial activity against food-borne pathogens such as Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria due to the CH antimicrobial effectiveness. These bioactive UV-blocking CH/EA films open the way to materials with potential for eco-friendly active packaging.
In the present review, we discuss the occurrence of ellagitannins (ETs) and ellagic acid (EA) and methods for their isolation from plant materials. We summarize analytical methods, including high-performance liquid chromatography–ultraviolet (HPLC–UV) and liquid chromatography–mass spectrometry (LC–MS), for the determination of ETs, EA and their bioactive metabolites urolithins (Uros) in samples of plant and food origin, as well as in biological samples, such as plasma, urine and feces. In addition, the current interest in the bioactivities of Uros is discussed in brief.
In this study the viability of the integrated exploitation of E. globulus leaf essential oil and triterpenic acids was evaluated through the development of a novel extraction process that can be implemented sequentially in a biorefinery context. Thus, essential oil (EO) collected by hydrodistillation was used for the first time as a bio-based solvent to recover triterpenic acids (TTAs) from the residue resulting from the EO recovery (from the hydrodistilled leaves). Ursolic, oleanolic, betulonic and betulinic acids were successfully extracted with EO with, for comparison purposes, its major component, 1,8-cineole (CO), showing TTAs extraction yields of 2.8 and 2.7% dw, respectively. Both EO and CO were particularly efficient in extracting ursolic (18.3 and 17.9 g kg⁻¹ dw) and oleanolic (6.0 and 5.7 g kg⁻¹ dw, respectively) acids, the major components of crude extracts. In addition, cytotoxicity evaluation showed that EO and CO crude extracts are non-toxic to macrophage cell lines at concentrations less than or equal to 0.04 and 0.08 mg mL⁻¹, respectively. Crude extracts dissolved in the EO and CO also showed higher anti-inflammatory activity than a synthetic mixture representative of the TTAs detected, demonstrating the synergistic effect between EO or CO and the extracted components. In summary, the EO is a potential bio-based solvent, which could be applied in biorefinery processes, replacing organic solvents such as n-hexane in the recovery of TTAs, without environmental side effects, and even with potential applications of the crude extracts themselves in the nutraceutical and pharmaceutical fields.
The current study was done to confirm the existence of stable nanoparticles of phyto-compounds, such as alizarin, lucidin, and rubiadin from Rubia tinctorum L. roots by employing the supercritical procedure. These compounds have a low bioaccessibility since; they are rarely soluble in aqueous media. Hence, preparation of a stable colloid of herbal extract in a nano suspension system can resolve this problem by reducing particle size. Moreover, central composite design (CCD) was exploited for analyzing the effect of pressure, CO2 flow rate, modifier volume, and oven temperature on antioxidant activity index (AAI) following application of supercritical procedure. Furthermore, dynamic light scattering (DLS), field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and liquid chromatography–mass spectrometry (LCMS) techniques were utilized to appraise properties of the prepared nanocolloids. Based on the results, demeanor of the particles changed after particle creation, demonstrating that the supercritical procedure results in the diminished accumulation of the particle and raising AAI for the extract. Hence, bioaccessibility of medicinal herb can be significantly enhanced in biological media and in -vitro testing determined their valuable antioxidant properties by comparison with standards and classifications.
• Eucalyptus is one of the most cultivated genera globally. Conversion of native forests into Eucalyptus spp. monocultures leads to species‐specific changes in the quality of the litter that contributes to the structure and function of allochthonous‐based aquatic systems.
• We used a microcosm approach to compare the relative importance of structural and chemical leaf trait variability among congeneric exotic Eucalyptus species (E. camaldulensis, E. globulus, E. grandis, and E. nitens) and two Portuguese native species—alder (Alnus glutinosa) and oak (Quercus robur)—on microbial‐mediated decomposition and invertebrate shredder (Trichoptera: Sericostoma vittatum) consumption.
• Structural leaf traits, rather than chemical characteristics, appeared to be the main determinants of leaf‐processing dynamics. Differences between the exotic species were mainly determined by the persistence (E. globulus, E. grandis, and E. nitens) or detachment (E. camaldulensis) of the cuticular barrier soon after immersion. Detachment favoured an earlier and higher level of fungal colonisation, as well as a higher mass loss.
• Sericostoma vittatum exhibited higher consumption rates when fed by the nitrogen‐rich and softer alder leaves, E. camaldulensis, and oak. Consistently lower consumption rates were observed in the other three Eucalyptus species (64–77% lower than E. camaldulensis). Leaf litter from these species was colonised by a lower number of fungal species and was dominated by Flagellospora curta.
• Results suggest that streams adjacent to E. camaldulensis monocultures receive a continuous supply of easily degradable organic matter throughout the year. The potential effect of subsidies from this species in alleviating the general negative impacts of Eucalyptus plantations on native bordered aquatic systems remains to be evaluated.
From ancient times, the medicinal properties of the different Eucalyptus species are well known. In fact, plants from this family have been used in folk medicine as antiseptics, and to treat different ailments of the upper respiratory tract such as sinus congestion, common cold, or influenza. Moreover, other biological activities were described for Eucalyptus species such as antioxidant and antimicrobial properties. In the last few decades, numerous investigations revealed that the compounds responsible for these properties are secondary metabolites that belonging to the group of phenolic compounds and are present in different parts of the plants such as leaves, bark, wood, fruits, and stumps. The increasing demand for natural compounds that can substitute synthetic antioxidants and the increase in resistance to traditional antibiotics have boosted the intense search for renewable natural sources containing substances with such bioactivities, as well as greener extraction technologies and avant-garde analytical methods for the identification of the target molecules. The literature data used in this paper were collected via Scopus (2001–2020) using the following search terms: Eucalyptus, extraction methods, phenolic compounds, and biological activities. This review collects the main studies related to the recovery of value-added compounds from different Eucalyptus species, as well as their biofunctional applications.
Eucalyptus barks contain complex biomass of constituents with considerable chemical and structural diversity. Reports about Eucalyptus sideroxylon Cunn. ex Woolls bark composition and biological activities are limited. Non-targeted metabolomic analysis via ultra-performance liquid chromatography-quadrupole-time-of-flight-photodiode array-mass spectrometry (UPLC-qTOF-PDA-MS) enabled first-time detection of 41 secondary metabolites of which 31 were identified including; 6 flavonoids, 4 ellagic acid derivatives, 8 triterpenes, 10 fatty acids and 3 miscellaneous. The isolation and structure elucidation of methyl morolate, β-sitosterol, syringaldeyhde and 7'-deoxyguajavadial A were reported. The bark methylene chloride: methanol (8:2) extract demonstrated significant (P < 0.01) in vitro anti-inflammatory activity through membrane stabilization, protein denaturation inhibition, anti-lipoxygenase, and proteinase inhibition assays. The strongest anti-inflammatory activity was via membrane stabilization (34.4%) as compared to diclofenac sodium (26%) at the same concentration (125 μg/mL). Our study represents the sole complete map for E. sideroxylon bark components and represents it as new anti-inflammatory drug.
The influence of tree height on the composition of bark extractives from Eucalyptus globulus and Eucalyptus nitens was investigated for its potential in the sourcing of valuable compounds. The bark of these trees was extracted at different heights to obtain lipophilic and hydrophilic compounds, which were chemically characterized. The extraction yield of lipophilic compounds was higher for E. globulus than for E. nitens . The type and proportion of the compounds changed with the tree variety and height. The main compounds detected were triterpenic acid derivatives, such as lupane, oleanane and ursane types, followed by fatty acids. The yield extraction of the hydrophilic compounds was higher for E. nitens than E. globulus . The total phenolic content, proanthocyanidins and antioxidant activity of the extracts increased with the tree height in both cases. However, the E. globulus extracts [half maximal inhibitory concentration (IC 50 ) = 13.8 ± 0.2 μg ml ⁻¹ ] showed higher antioxidant activity than did the E. nitens extracts (IC 50 = 22.8 ± 0.2 μg ml ⁻¹ ). Differences in the extract composition and the spatial conformation of the molecules (steric effect) could also help to obtain a higher antioxidant capacity from E. globulus extracts. These results show that differentiation by tree height can contribute to the selective enrichment of these valuable compounds.
This study aimed to assess the effect of high pressure (300 and 600 MPa) and enzymatic extraction (pectinase and cellulase) on the phenolic compounds profile, antioxidant capacity and antimicrobial activity of extracts from pomegranate by-products. Antimicrobial activity against eight different strains of pathogenic and contaminant bacteria and against five beneficial bacteria including Lactobacillus and Bifidobacterium strains were determined. The maximum level of total phenolic content, as well as antioxidant capacity were observed at 300 MPa, however enzymatic extraction did not improve the extraction yields. Punicalagin isomers and bis-hexahydroxydiphenoyl-glucoside isomer were the most abundant phenolic compounds found in the extracts. All pomegranate peel extracts demonstrated selective antimicrobial activity against all pathogenic bacteria without affecting beneficial ones. Pressurized extracts presented lower minimum inhibitory concentration against Bacillus cereus and Pseudomonas aeruginosa and lower minimum bactericidal concentration against B. cereus, while, enzymatic extracts presented lower minimum bactericidal concentration for Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus and Listeria monocytogenes. Principal component analyses reveled that antioxidant activity and phenolic compounds content were strongly related with antimicrobial activity. Pomegranate peels extracts obtained by high pressure extraction could so be used as a source of high added-value bioactive compounds for antioxidant and antimicrobial applications.
The aim of this study was to optimise the ultrasound-assisted extraction of the total polyphenol content (TPC) and antioxidant activity from Maytenus macrocarpa bark by means of response surface methodology (RSM). The effect and interactions of temperature, time, particle size, solid:solvent ratio and water:ethanol ratio were analysed by using a fractional factorial design type 2⁵⁻¹. The most significant factors were: temperature, particle size and time. The RSM was applied to the optimisation of the TPC and two total antioxidant activities [Ferric reducing antioxidant power (FRAP) and 2,2 -azino-bis (3-ethylbenthiozoline-6-sulphonic acid) (ABTS)] as response variables. Four polynomial models were applied; the quadratic model was the most adequate one, with an adjusted R² value of 0.9422. M. macrocarpa has a considerable TPC that contributes to its antioxidant activity. The best results from the analysis of correlations were found in the FRAP versus TPC and ABTS versus FRAP, with a Pearson’s r coefficient of 0.961 and 0.953, respectively.
Eucalyptus is one of the most important and highly exploited genus in family Myrtaceae. An UPLC/PDA/ESI-qTOF-MS method was adopted to identify Eucalyptus sideroxylon Cunn. ex Woolls leaves phytoconstituents. Cytotoxicity of E. sideroxylon leaves phloroglucinol-rich extract (PGRE) on VERO cells was determined. The antiviral effect of PGRE against hepatitis A (HAV), herpes simplex type 1 (HSV-I), herpes simplex type 2 (HSV-II), coxsackie (CoxB4), and adenoviruses was in vitro evaluated using MTT assay (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide). UPLC-MS analysis allowed the identification of 70 metabolites including: 26 triterpenes, 13 phloroglucinols, 8 fatty acids, 5 flavonoids, 5 oleuropeic acid glucosides, 3 gallic acid derivatives, and 10 miscellaneous. Twenty four metabolites identified in the leaves of E. sideroxylon and four in the genus Eucalyptus are reported herein for the first time. PGRE was found to be non-cytotoxic; the concentration that reduced the cell viability by 50% (CC50) was 0.808mg/mL. Maximum non-toxic concentration (MNTC) of PGRE on Vero cells was 0.312mg/mL. The best antiviral activity was observed against HSV-II. Its mechanism was through decreasing the viral replication (IC50 189.36μg/mL, 87.65% inhibition) and attachment on Vero cells (IC50 199.34μg/mL, 83.13% inhibition) rather than virucidal effect (IC50 293.1μg/mL, 50.68% inhibition). This study provides a complete map for E. sideroxylon leaves composition. It also suggests the plant as a source of new antiviral agents.
Several cultivars of peach fruit (Prunus persica L.) were investigated. Their phenolic composition and concentration were assessed by LC-MS. Concentrations were calculated in mg per g of dry weight extract. Their antioxidant capacity (Folin-Ciocalteu, ORAC, DPPH, ABTS, PFRAP and ICA), inhibitory property against β–amyloid and α-synuclein fibril formation and protective capacity against Aβ-induced toxicity on PC12 cell lines (viability assessed by MTT assay and intracellular ROS production by DCFH-DA assay) were evaluated. Fifteen different phenolic compounds were identified and quantified. In particular, new isorhamnetin derivatives were identified. Phenolic contents were ranged between 19-82 mg/g. Spring Belle extract had the highest content and Romea the lowest. Except for the ICA assay, a good correlation between phenolic content and the antioxidant capacities of peach fruit extracts was found, indicating that phenolic compounds are major contributors to their antioxidant capacity. Results indicate that the phenolic extract of peach cultivars inhibits Aβ and αS fibril formation and protects PC12 cell lines against Aβ–induced toxicity.
A high-performance liquid chromatographic (HPLC) method coupled with diode-array detection (DAD) was optimized for the qualitative analysis of aqueous extracts of Cyclopia genistoides. Comprehensive insight into the phenolic profile of unfermented and fermented sample extracts was achieved with the identification of ten compounds based on comparison with authentic reference standards and the tentative identification of 30 additional compounds by means of electrospray ionization mass spectrometry (ESI-MS) and tandem MS detection. Three iriflophenone-di-O,C-hexoside isomers, three xanthone-dihydrochalcone derivatives and one dihydrochalcone are herein tentatively identified for the first time in C. genistoides. Of special interest is one iriflophenone-di-O,C-hexoside present in large amounts. New compounds (tentatively) identified for the first time in this species, and also in the genus Cyclopia, include two aromatic amino acids, one flavone, an iriflophenone-di-C-hexoside, a maclurin-di-O,C-hexoside, two tetrahydroxyxanthone-C-hexoside isomers, a tetrahydroxyxanthone-di-O,C-hexoside, two symmetric tetrahydroxyxanthone-C-hexoside dimers, nine glycosylated flavanone derivatives and five glycosylated phenolic acid derivatives. The presence of new compound subclasses in Cyclopia, namely aromatic amino acids and glycosylated phenolic acids, was demonstrated. The HPLC-DAD method was successfully validated and applied to the quantitative analysis of the paired sample extracts. In-depth analysis of the chemical composition of C. genistoides hot water extracts gave a better understanding of the chemistry of this species that will guide further research into its medicinal properties and potential uses.
Rhizoma Smilacis glabrae, a traditional Chinese medicine (TCM) as well as a functional food, has been commonly used for detoxification treatments, relieving dampness and as a diuretic. In order to quickly define the chemical profiles and control the quality of Smilacis glabrae, ultra high performance liquid chromatography coupled with electrospray ionization hybrid linear trap quadrupole orbitrap mass spectrometry (UHPLC-ESI/LTQ-Orbitrap-MS) was applied for simultaneous identification and quantification of its bioactive constituents. A total of 56 compounds, including six new compounds, were identified or tentatively deduced on the basis of their retention behaviors, mass spectra, or by comparison with reference substances and literature data. The identified compounds belonged to flavonoids, phenolic acids and phenylpropanoid glycosides. In addition, an optimized UHPLC-ESI/LTQ-Orbitrap-MS method was established for quantitative determination of six marker compounds from five batches. The validation of the method, including linearity, sensitivity (LOQ), precision, repeatability and spike recoveries, was carried out and demonstrated to be satisfied the requirements of quantitative analysis. The results suggested that the established method would be a powerful and reliable analytical tool for the characterization of multi-constituent in complex chemical system and quality control of TCM.
A new formal classification of the genus Eucalyptus is presented. It divides the genus into seven polytypic subgenera: E. subg. Angophora, E. subg. Corymbia, E. subg. Blakella, E. subg. Eudesmia, E . subg. Symphyomyrtus, E. subg. Minutifructa and E. subg. Eucalyptus, and six monotypic subgenera: E. subg. Acerosa, E. subg. Cruciformes, E. subg. Alveolata, E. subg. Cuboidea, E. subg. Idiogenes and E. subg. Primitiva. The system is intentionally phylogenetic, proceeding from the generally assumed primitive ‘apples’ (E. subg. Angophora) and bloodwoods (E. subg. Corymbia) to the most advanced and modified group, the monocalypts (E. subg. Eucalyptus). The genus Corymbia Hill & Johnson is subsumed under Eucalyptus and is represented by E. subg. Corymbia (the bloodwoods) and E. subg. Blakella (the ghostgums).
New infrageneric taxa are diagnosed and their names typified, while brief digests in English are given for established taxa. Three species of the former genus Angophora have names with epithets preoccupied by names of other Eucalyptus species and new names are presented for them. The study is introduced by a brief historical summary of previous work in Eucalyptus, an apologia for the inclusion of Angophora, the reason for requirement of a new classification and notes on the nomenclature used. A new infrageneric rank, ‘supraspecies’, is introduced and is intentionally divorced in application (as a rank) from the similar sounding ‘superspecies’. All species recognised by the author are named and assigned in this system.
Eucalypts are the world’s most widely planted hardwood trees. Their outstanding diversity, adaptability and growth have made them a global renewable resource of fibre and energy. We sequenced and assembled >94% of the 640-megabase genome of Eucalyptus grandis. Of 36,376 predicted protein-coding genes, 34% occur in tandem duplications, the largest proportion thus far in plant genomes. Eucalyptus also shows the highest diversity of genes for specialized metabolites such as terpenes that act as chemical defence and provide unique pharmaceutical oils. Genome sequencing of the E. grandis sister species E. globulus and a set of inbred E. grandis tree genomes reveals dynamic genome evolution and hotspots of inbreeding depression. The E. grandis genome is the first reference for the eudicot order Myrtales and is placed here sister to the eurosids. This resource expands our understanding of the unique biology of large woody perennials and provides a powerful tool to accelerate comparative biology, breeding and biotechnology.
The comprehensive identification of phenolic compounds in food and beverages is a crucial starting point for assessing their biological, nutritional, and technological properties. Pomegranate (Punica granatum L.) has been described as a rich source of (poly)phenolic components, with a broad array of different structures (phenolic acids, flavonoids, and hydrolyzable tannins) and a quick, high throughput, and accurate screening of its complete profile is still lacking. In the present work, a method for UHPLC separation and linear ion trap mass spectrometric (MSⁿ) characterization of pomegranate juice phenolic fraction was optimized by comparing several different analytical conditions. The best solutions for phenolic acids, anthocyanins, flavonoids, and ellagitannins have been delineated and more than 70 compounds have been identified and fully characterized in less than one hour total analysis time. Twenty-one compounds were tentatively detected for the first time in pomegranate juice. The proposed fingerprinting approach could be easily translated to other plant derived food extracts and beverages containing a wide array of phytochemical compounds.
The chemical composition of the dichloromethane extract of Eucalyptus globulus wood cultivated in Portugal was studied by gas chromatography-mass spectrometry, prior to and after alkaline hydrolysis. In addition to previously identified lipophilic extractives, 22 free or esterified compounds (14 fatty acids, 2 fatty alcohols and 6 aromatic compounds) were identified for the first time in E. globulus wood. One of these, ferulic acid, was esterified with three different fatty alcohols and with two alpha-hydroxyfatty acids. Some of the newly identified compounds, particularly the alpha-hydroxyfatty acids are responsible for recently reported pitch problems during pulp production in a Portuguese mill. The differences found in the E. globulus chemical composition, when compared with published data, are expected to be related to variations in the location of growth and genetic factors.
A comparative study on the triterpenic acids composition of the outer barks of several Eucalyptus species (E. globulus, E. grandis, E. urograndis, E. maidenii and E. nitens) is reported. The contents of the main triterpenic acids identified in the five species varied between 4.5 g/kg in E. urograndis and 21.6 g/kg in E. nitens. It has been observed that, out of these Eucalyptus species outer barks, those from temperate and Mediterranean zones, namely E. nitens and E. globulus, are richer in triterpenic acids than the species from sub-tropical and tropical regions. Furthermore, E. globulus outer bark is clearly the richest in ursane acids, while E. nitens outer bark is the richest in oleanane and lupane acids.
The lipophilic extractives of Eucalyptus globulus, Eucalyptus grandis, Eucalyptus urograndis, Betula verrucosa and Acacia mangium woods and of the corresponding ECF bleached kraft pulps, were characterized by GC-MS. The five hardwoods showed significant differences in the content and composition of the main families of extractives, namely fatty acids, long chain aliphatic alcohols and sterols. Significant differences in the composition persist after wood pulping and ECF bleaching of pulps. The fate of the various types of extractives during the wood and pulp processing is discussed. Long chain aliphatic acids and alcohols are quite stable during the pulp production and are retained to a great extent in the final bleached pulp; ∆ 5 sterols are mostly oxidized and partially retained in the pulps, while ∆ 7 sterols are completely degraded and/or dissolved. B. verrucosa and A. mangium bleached pulps show contents of fatty acids about 4 and 20 times higher than that of Eucalyptus pulps, respectively, while the content of long chain aliphatic alcohols in A. mangium pulp is of the order of 100 times higher than Eucalyptus and B. verrucosa pulps.
The lipid and lignin compositions of woods from the eucalypt species Eucalyptus globulus, E. nitens, E. mai-denii, E. grandis, and E. dunnii have been characterized. The lipid composition was analyzed by GC and GC/MS using short-and medium-length high-temperature cap-illary columns, which allowed the detection of intact high-molecular-weight compounds. Similar lipid compositions were observed in all eucalypt woods, which were domi-nated by sitosterol, sitosterol esters and sitosteryl 3b-D-glucopyranoside. These substance classes are mainly responsible for pitch deposition during kraft pulping of eucalypt wood. However, some quantitative differences were found in the abundance of different lipid classes, with wood from E. globulus containing the lowest amounts of these pitch-forming compounds. The lignins of all eucalypt woods were analyzed in situ (without pre-vious isolation) by pyrolysis-GC/MS. A predominance of syringyl (S) over guaiacyl (G) lignin units was observed and the S/G ratio was in the range from 2.7 to 4.1. E. globulus wood had the highest S/G ratio, a finding that, together with its low lignin content, explains its easy de-lignification under kraft cooking conditions.
Heartwoods of 22 African tropical wood species were extracted with methanol and the contents of total phenolic compounds in
these extracts were measured. Three bioassays were conducted to evaluate the antioxidant activity, tyrosinase inhibitory activity,
and antifungal activity of the methanol extracts. The results indicated that the extracts from 13 species exhibited high antioxidant
potential, and their inhibitory concentrations that caused 50% scavenging of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical
(IC50) were less than 10 μg/ml. The crude extract from Cylicodiscus gabunensis showed the highest antioxidant activity, and was even higher than that of (+)-catechin, which is known as a potent antioxidant.
There was a good correlation between the antioxidant activity and the content of total phenolic compounds, indicating that
phenolic compounds played a predominant role in the antioxidant property of the wood extracts. Among all 22 species, only
1 species, Milicia excelsa, contained extractives that showed very high tyrosinase inhibitory activity. The extracts from 9 species showed high antifungal
activity. No consistent relationship was observed between the tyrosinase inhibitory activity or antifungal activity and the
content of total phenolics in the extracts.
Eucalyptus is the most widely planted hardwood crop in the tropical and subtropical world because of its superior growth, broad adaptability and multipurpose wood properties. Plantation forestry of Eucalyptus supplies high-quality woody biomass for several industrial applications while reducing the pressure on tropical forests and associated biodiversity. This review links current eucalypt breeding practices with existing and emerging genomic tools. A brief discussion provides a background to modern eucalypt breeding together with some current applications of molecular markers in support of operational breeding. Quantitative trait locus (QTL) mapping and genetical genomics are reviewed and an in-depth perspective is provided on the power of association genetics to dissect quantitative variation in this highly diverse organism. Finally, some challenges and opportunities to integrate genomic information into directional selective breeding are discussed in light of the upcoming draft of the Eucalyptus grandis genome. Given the extraordinary genetic variation that exists in the genus Eucalyptus, the ingenuity of most breeders, and the powerful genomic tools that have become available, the prospects of applied genomics in Eucalyptus forest production are encouraging.
The chemical compositions of the lipophilic extractives from four clones of Eucalyptus urograndis cultivated in Brazil were studied by gas chromatography-mass spectrometry (GC-MS) before and after alkaline hydrolysis. The four E. urograndis clones showed similar amounts of dichloromethane soluble (lipophilic) extractives (0.38-0.55% w/w). The major groups of compounds identified in the lipophilic fraction of extractives consisted mainly of fatty acids (mainly palmitic linoleic and oleic acids and small amounts of a- and w-hydroxyacids), steroids (mainly b-sitosterol, b-sitostanol), followed by minor amounts long chain aliphatic alcohols, hydrocarbons and aromatic compounds. The relative abundances of these groups were similar for three of the clones with exception of the clone Ugc, which was shown to have much higher amounts of fatty acids and sterols. The high amounts of extractives found in these clones, and particularly of Ugc, when compared with other Eucalyptus species, suggests an increased risk of pitch formation during bleached pulp production.
Phenolic compounds are plant secondary metabolites that present many biological effects including antioxidant and antimicrobial activities. Studies have shown that these compounds can also inhibit quorum sensing bacterial communication. The aim of this study was to characterize the centesimal composition, mineral and phenolic content, to determine the antioxidant and antimicrobial effect as well as the inhibition of quorum sensing by the phenolic extract obtained from wild strawberry (Rubus rosaefolius). Centesimal composition and minerals were in the range expected for fruits of the Rubus generum, even though Fe and Zn presented higher levels. The phenolic content was 5902.89 mg GAE/L, also approaching the levels found for fruits of Rubus sp. The antioxidant activity determined through the ABTS method was 162.4 ± 5.6 and 120.8 ± 1.5 μM Trolox/g of fruit in the DPPH assay, indicating an elevated potential for ABTS and medium potential for DPPH method. The phenolic extract was able to inhibit all the evaluated bacteria presenting MICs in the range of 491.90–1475.74 mg GAE/L. In sub-MIC concentrations, the phenolic extract inhibited all the phenotypes typically regulated by quorum sensing in bacteria, including violacein production, swarming motility and biofilm formation. The phenolic extract of R. rosaefolius presented antioxidant, antimicrobial and anti-quorum sensing activities which are in agreement with previous studies linking phenolic compounds to these properties.
A method for the screening of antioxidant activity is reported as a decolorization assay applicable to both lipophilic and hydrophilic antioxidants, including flavonoids, hydroxycinnamates, carotenoids, and plasma antioxidants. The pre-formed radical monocation of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS*+) is generated by oxidation of ABTS with potassium persulfate and is reduced in the presence of such hydrogen-donating antioxidants. The influences of both the concentration of antioxidant and duration of reaction on the inhibition of the radical cation absorption are taken into account when determining the antioxidant activity. This assay clearly improves the original TEAC assay (the ferryl myoglobin/ABTS assay) for the determination of antioxidant activity in a number of ways. First, the chemistry involves the direct generation of the ABTS radical monocation with no involvement of an intermediary radical. Second, it is a decolorization assay; thus the radical cation is pre-formed prior to addition of antioxidant test systems, rather than the generation of the radical taking place continually in the presence of the antioxidant. Hence the results obtained with the improved system may not always be directly comparable with those obtained using the original TEAC assay. Third, it is applicable to both aqueous and lipophilic systems.
The chemical composition of Eucalyptus grandis wood used in Brazil for cellulose production was described in this paper. The wood sample of E. grandis was extracted with dichloromethane, acetone and ethanol:toluene (1:2 v v -1) and yielded, respectively, 0.06 g%, 1.75 g% and 1.62 g% of extracts. The chemical analysis of the extracts by FT-IR and CG-MS lead to the identification of 61 compounds. Fatty acids and steroids were the major components, representing 26.45% and 61.34%, respectively, in the dichloromethane extract, 41.99% and 15.22% in acetone and 40.52% and 19.80% in ethanol:toluene (1:2 v v-1) extracts. Among all compounds identified, β-sitosterol was the predominant steroid and several uncommon α-and ω-hydroxyl fatty acids were also found in all three extracts. Polar aromatic compounds and carbohydrates were extracted mainly by acetone, followed by ethanol:toluene mixture. The results obtained showed that acetone is the best solvent for the evaluation of the wood lipophilic extract content. These data are important for the pulp industry to establish new methodology for pitch control, and also represent a new contribution on the knowledge of the Eucalyptus wood chemistry.
Lipophilic wood extractives have serious negative impacts on both pulping process and quality of produced pulp. This study aimed at identifying suitable wood materials for pulping with respect to their lipophilic extractives contents. The effect of site, species and tree sizes on the amount of lipophilic extractives was evaluated. The lipophilic extractives from selected Eucalyptus species used for pulping in South Africa were quantified using gas chromatography–mass spectrometry. It was revealed by the use of analysis of covariance (ANCOVA) that the quantitative variation of lipophilic extractives in Eucalyptus woods is significantly affected by respective sites and tree species. Principal component analysis (PCA) revealed the correlation of the amount of lipophilic extractives in wood materials with tree species/clones and site soil composition. Thus, high amounts of lipophilic extractives were found in Eucalyptus trees grown at sites with a high composition of clay soil and organic matter. Whereas, Eucalyptus dunnii was found to contain a higher amount of lipophilic extractives than Eucalyptus grandis in all the sampled sites, implying an increased risk of pitch formation during the pulping process.
The aim of the present work was to identify the extractable phenolic compounds present in cork from Quercus suber L. The structures of thirty three compounds were tentatively identified by liquid chromatography coupled to electrospray ionisation mass spectrometry (HPLC–DAD/ESI–MS). The majority of those compounds were gallic acid derivatives, in the form of either galloyl esters of glucose (gallotannins), combinations of galloyl and hexahydroxydiphenoyl esters of glucose (ellagitannins), dehydrated tergallic-C-glucosides or ellagic acid derivatives. Others were found to correspond to low molecular weight phenolic compounds, like acids and aldehydes. Mongolicain, a flavanoellagitannin in which hydrolysable tannin and flavan-3-ol moieties are connected through a carbon–carbon linkage, was also detected in cork from Q. suber L. The results illustrate the rich array of phenolic compounds present in cork.
The wood of Eucalyptus globulus contains several pentacyclic diterpenes with oleane, ursane and lupane skeleta. In addition to the well known compounds β-amyrin, erythrodiol, uvaol, acetyloleanolic, acetylbetulinic, acetylursolic, betulinic, ursolic, 23-hydroxyursolic and trans-p-methoxycinnamoyloxy-ursolic acids, three new triterpenoids have been isolated: methyl cis-p-methoxycinnamoyloxyoleanolate, methyl cis-p-methoxycinnamoyloxyursolate and methyl 11α-methoxy-3-acetoxyursolate.
The phenolic composition of cork powder and black condensate, two by-products from the cork industry, was investigated by the first time using high-performance liquid chromatography-multi-stage mass spectrometry (HPLC–MSn). The same methodology of extraction was applied to cork, for comparative purposes. Eighteen phenolic compounds were identified in cork, five of them are reported for the first time as its constituents. Sixteen and thirteen phenolic compounds were identified as cork powder and black condensate components, respectively, with only one compound of each residue published before as its constituent. The antioxidant activity of the extracts was evaluated, being, to our knowledge, the first study concerning the antioxidant activity of these cork residues. The extracts present an antioxidant activity higher than BHT, with black condensate showing the lowest IC50 value. These results, together with the phenolic content values, demonstrate the high potential of these residues as source of high value compounds.
The chemical composition of the dichloromethane extracts of inner and outer barks of E. Globulus were studied by gas chromatography-mass spectrometry. The two fractions show very different chemical compositions: triterpenic acids, such as betulinic, ursolic and oleanolic acids, were the major components of the outer bark extract, whereas β-sitosterol and β-amirin along with palmitic, linoleic and oleic acids predominate in the inner bark extract. Several α- and β-hydroxy fatty acids, recently reported for the first time as E. globulus wood components, were also identified in the outer and inner barks. In the outer bark extract, minor amounts of ferulic acid esters, also previously reported to occur in E. globulus wood were identified. In general, the inner bark lipophilic extractives resemble more closely that of E. globulus wood.
The phenolic composition of Eucalyptus grandis, Eucalyptus urograndis (E. grandis × E. urophylla) and Eucalyptus maidenii bark is reported for the first time. High performance liquid chromatography–electrospray ionization mass spectrometry (HPLC–ESI-MS) and tandem mass spectrometry (MSn) analysis of the methanol:water (50:50) extracts allowed to identify thirteen, twelve and twenty-four phenolic compounds in E. grandis, E. urograndis and E. maidenii bark extracts, respectively. Furthermore, ellagic acid-rhamnoside, dihydroxy-isopropylchromone-hexoside and dihydroxy-(methylpropyl)isopropylchromone-hexoside are referenced for the first time as constituents of Eucalyptus species. Epicatechin and quercetin-glucuronide are the major phenolic compounds in E. grandis and E. urograndis bark, followed by ellagic acid-rhamnoside and ellagic acid in E. grandis and by galloyl-bis-hexahydroxydiphenoyl (HHDP)-glucose and gallic acid in E. urograndis. Catechin, chlorogenic acid and methyl-ellagic acid-pentose are the major compounds in E. maidenii bark. The phenolic content
of the three extracts shows a positive correlation with their antioxidant activities, evaluated by 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) radical scavenging, showing activity values between those of two commercial antioxidants, ascorbic acid and butylated hydroxytoluene (BHT). These results, together with the phenolic composition, confirm the
high potential of these species as source of biologically active phenolic compounds.
Two new euglobals, G6 and G7 were isolated from the hexane fraction of the methanol extract of
the leaves of Eucalyptus grandis. These have phloroglucinol-monoterpene structures. Both euglobals have a
formyl-isovaleroyl phloroglucinol moiety fused with ?-terpinene. Their structures were elucidated on the basis
of spectral evidences.
A comparative study on the triterpenic acids composition of the outer barks of several Eucalyptus species (E. globulus, E. grandis, E. urograndis, E. maidenii and E. nitens) is reported. The contents of the main triterpenic acids identified in the five species varied between 4.5 g/kg in E. urograndis and 21.6 g/kg in E. nitens. It has been observed that, out of these Eucalyptus species outer barks, those from temperate and Mediterranean zones, namely E. nitens and E. globulus, are richer in triterpenic acids than the species from sub-tropical and tropical regions. Furthermore, E. globulus outer bark is clearly the richest in ursane acids, while E. nitens outer bark is the richest in oleanane and lupane acids.
An approach was established to analyze the chemical profiling of Xiao-Cheng-Qi Decoction (XCQD) using liquid chromatography
coupled with electrospray ionization tandem mass spectrometry. XCQD consisted of three herbal medicines (Rhubarb, Fructus Aurantii Immaturus and Cortex Magnoliae Officinalis). The traditional water extractive method was applied in the sample preparation, which was identical with clinical use. The
characteristic fragmentation pathways of 17 reference compounds were comprehensively studied, including precursors of tannins,
flavonones, anthraquinones and lignan. In total, 71 constituents were identified or tentatively characterized based on their
mass spectrometry fragmentations and chromatographic behaviors. By comparing their relative contents, flavanones and anthraquinones
were supposed to be used together for the quality control of XCQD. Further pharmacology and pharmacokinetics investigations
should be performed on the basis of the present chemical profiling study.
The chemical composition of the lipophilic extracts of the inner and outer bark fractions of Eucalyptus grandis and Eucalyptus urograndis (E. grandis×Eucalyptus urophylla) cultivated in Brazil and Eucalyptus maidenii, cultivated in Portugal was studied by gas chromatography–mass spectrometry. The extracts were shown to be mainly composed of triterpenic compounds (along with mono and sesquiterpenes in E. maidenii) followed smaller amounts of fatty acids, fatty alcohols, and aromatic compounds.Triterpenic acids (mainly ursolic, betulinic and oleanolic acids), are particularly abundant in outer barks representing 5.2g/kg, 5.7g/kg and 9.3g/kg in E. urograndis, E. grandis and E. maidenii outer barks, respectively. Although these compounds were found in considerably smaller amounts than those previously reported for Eucalyptus globulus, the total amounts of bark generated every year in South American pulp mills using E. urograndis and E. grandis, as well as the growth potential of E. maidenii plantations, the bark residues from these species are obvious candidates for the extraction of valuable triterpenic compounds.
A mass spectrometric method based on the combined use of fast atom bombardment collisionally-induced dissociation (CID) and tandem mass spectrometry has been used for the structural characterization of free and conjugated flavone and flavonol aglycones. Low-energy CID spectra of the [M + H]+ (or Y+0) ions show simple fragmentation patterns, which allow characterization of the substituents in the A and B rings and, in particular, differentiation between flavones and flavonols. A systematic nomenclature for product ions produced from protonated molecules under CID conditions is proposed. © 1997 John Wiley & Sons, Ltd.
The effectiveness of subcritical liquid water processing for extraction of antioxidants from the leaves of Eucalyptus grandis biomass was evaluated by determining the capability of the processed samples to scavenge peroxynitrite radicals in vitro,
as compared with the extracts obtained by conventional extraction. Pyrogallol (1), 5-hydroxymethyl-2-furaldehyde (2), and 4,4,6,6-tetramethyl-3,5-dioxo-cyclohex-1-enecarboxylic acid (3) were identified as the major products obtained from the subcritical liquid water extracts. Among these, pyrogallol (1) exhibited stronger antioxidant activity than butylated hydroxytoluene, which was used as a standard for the antioxidant
activity measurement.
Five new euglobals possessing the phloroglucinol-monoterpene structure, euglobals G8–G12, together with a known euglobal-IIc were isolated from the hexane fraction of the methanol extract of the leaves of Eucalyptus grandis. Euglobal-G8 is an adduct of formyl-isovaleroyl-phloroglucinol and γ-terpinene whereas –G9, –G10 and –G11 have the same phloroglucinol moiety fused with α-terpinene, while Euglobal-G12 has terpinolene fused with the same phloroglucinol moiety. The structures of these compounds were elucidated on the basis of spectral evidences. Biomimetic synthesis of euglobals suggests that these compounds are derived biogenetically by the Diels–Alder type cycloaddition of the corresponding terpenes with an ortho-quinone methide generated from grandinol.
At present, microbial and enzymatic preparations for the control of triglyceride-containing pitch deposits during the manufacture of mechanical and sulfite paper is commercially available. However, biotechnological products for pitch control in other pulping processes, such as alkaline pulping, are under development. These products include new fungi for the removal of steroids involved in pitch deposit formation in chlorine-free pulps, to be used as a biological pretreatment of wood before pulping. Simultaneously, tailor-made enzymes are being produced using protein-engineering techniques, enabling the specific removal of pitch contaminant compounds from paper pulp.
Scavenging of DPPH free radical is the basis of a common antioxidant assay. A number of protocols have been followed for this assay resulting in variation in the results of different laboratories. We present a perspective of the protocols followed by different workers with incongruity in their results and recommend a standard procedure within the sensitivity range of spectrophotometry. Three common standard antioxidants viz. ascorbic acid, BHT and propyl gallate have been used in this study. The IC50 values for ascorbic acid and propyl gallate were 11.8 μM and 4.4 μM in methanol and 11.5 μM and 4.7 μM in buffered methanol as reaction medium, respectively. The free radical scavenging by BHT was markedly influenced by the reaction medium. The IC50 values were 60.0 μM and 9.7 μM when the reaction was done in methanol and buffered methanol, respectively.
Phenolic phytochemicals from food-grade plants that are antioxidants are an important part of a healthy diet in a global population that is projected to reach 9 billion in the next 50 years. Such phytochemicals are being targeted for designing conventional foods with added health benefits and are called functional foods. These value-added foods are needed for dietary support to manage major oxidation-linked diseases such as diabetes, cardiovascular diseases, arthritis, cognition diseases and cancer. Plants produce phenolic metabolites during growth and developmental and stress adaptation responses. These phenolic phytochemicals can be targeted for designing functional foods and in order to design consistent food-grade phytochemical profiles for safety and clinical relevancy, novel tissue culture and bioprocessing technologies have been developed. These are based on the model that phenolic metabolites in plants are efficiently produced through an alternative mode of metabolism linking proline synthesis with the pentose phosphate pathway. Proline biosynthesis coupled to the pentose phosphate pathway stimulates the synthesis of NADPH2 and sugar phosphates for anabolic pathways, including phenolic and antioxidant response pathways. The reducing equivalents for mitochondrial oxidative phosphorylation are provided by proline replacing NADH, with oxygen being the terminal electron acceptor. Using this system, techniques have been developed to isolate high phenolic clonal lines of food-grade plants from single heterozygous seeds. Applying the same model, elicitation concepts and techniques have been used to over-produce phenolic metabolites in seeds and sprouts. In both clonal and seed sprout systems, exogenous treatment of phenolic phytochemicals from a non-target species elicited endogenous stimulation of phenolic synthesis and potentially an antioxidant response. From these initial plant antioxidant response investigations, a model has been proposed in which the proline-linked pentose phosphate pathway is critical for modulating protective antioxidant response pathways in diverse biological systems, including humans. The proposed proline-linked pentose phosphate pathway model, when confirmed precisely, provides a mechanism for understanding the mode of action of phenolic phytochemicals in modulating antioxidant pathways in relation to human health. This can provide dietary and nutritional mechanisms as well as new strategies to manage the oxidation-linked diseases through improvement of host physiological response. In other environmental applications, this model can be used to screen and design plants targeted for phytoremediation of aromatic pollutants and adaptation of plants in various stressed environments, including outdoor adaptation of tissue culture and transplanted seedlings for better food production.
The chemical compositions of the lipophilic extractives from four clones of Eucalyptus urograndis cultivated in Brazil were studied by gas chromatography-mass spectrometry (GC-MS) before and after alkaline hydrolysis. The four E. urograndis clones showed similar amounts of dichloromethane soluble (lipophilic) extractives (0.38-0.55% w/w). The major groups of compounds identified in the lipophilic fraction of extractives consisted mainly of fatty acids (mainly palmitic linoleic and oleic acids and small amounts of - and -hydroxyacids), steroids (mainly -sitosterol, -sitostanol), followed by minor amounts long chain aliphatic alcohols, hydrocarbons and aromatic compounds. The relative abundances of these groups were similar for three of the clones with exception of the clone Ugc, which was shown to have much higher amounts of fatty acids and sterols. The high amounts of extractives found in these clones, and particularly of Ugc, when compared with other Eucalyptus species, suggests an increased risk of pitch formation during bleached pulp production.
A method for the screening of antioxidant activity is reported as a decolorization assay applicable to both lipophilic and hydrophilic antioxidants, including flavonoids, hydroxycinnamates, carotenoids, and plasma antioxidants. The pre-formed radical monocation of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS*+) is generated by oxidation of ABTS with potassium persulfate and is reduced in the presence of such hydrogen-donating antioxidants. The influences of both the concentration of antioxidant and duration of reaction on the inhibition of the radical cation absorption are taken into account when determining the antioxidant activity. This assay clearly improves the original TEAC assay (the ferryl myoglobin/ABTS assay) for the determination of antioxidant activity in a number of ways. First, the chemistry involves the direct generation of the ABTS radical monocation with no involvement of an intermediary radical. Second, it is a decolorization assay; thus the radical cation is pre-formed prior to addition of antioxidant test systems, rather than the generation of the radical taking place continually in the presence of the antioxidant. Hence the results obtained with the improved system may not always be directly comparable with those obtained using the original TEAC assay. Third, it is applicable to both aqueous and lipophilic systems.
Some of the recent advances in flavonoid research are reviewed. The role of anthocyanins and flavones in providing stable blue flower colours in the angiosperms is outlined. The contribution of leaf flavonoids to UV-B protection in plants is critically discussed. Advances in understanding the part played by flavonoids in warding off microbial infection and protecting plants from herbivory are described. The biological properties of flavonoids are considered in an evaluation of the medicinal and nutritional values of these compounds.
At present, microbial and enzymatic preparations for the control of triglyceride-containing pitch deposits during the manufacture of mechanical and sulfite paper is commercially available. However, biotechnological products for pitch control in other pulping processes, such as alkaline pulping, are under development. These products include new fungi for the removal of steroids involved in pitch deposit formation in chlorine-free pulps, to be used as a biological pretreatment of wood before pulping. Simultaneously, tailor-made enzymes are being produced using protein-engineering techniques, enabling the specific removal of pitch contaminant compounds from paper pulp.
The potential of cork from Quercus suber L. grown in Algeria as a source of bioactive lipophilic and phenolic compounds
- R Touati
- S A O Santos
- S M Rocha
- K Belhamel
- A J D Silvestre
Touati, R., Santos, S.A.O., Rocha, S.M., Belhamel, K., Silvestre, A.J.D., 2015. The
potential of cork from Quercus suber L. grown in Algeria as a source of bioactive
lipophilic and phenolic compounds. Ind. Crops Prod. 76, 936-945.
The potential of cork from Quercus suber L. grown in Algeria as a source of bioactive lipophilic and phenolic compounds
- Touati