Soleya Dagnon

• PhD
• Professor (Associate) at Plovdiv University

Helichrysum italicum has piqued the interest of many researchers in recent years, mostly for its essential oil, but increasingly for its polyphenolic content as well. In the current study, we examine the polyphenolic composition of H. italicum grown in Bulgaria. The polyphenolic complex was fractionated with solvents of various polarities, includin...

In the present work, we have investigated the polyphenolic composition of Chenopodium botrys from Bulgaria. The polyphenols were fractionated with solvents of varying polarity (n-hexane, chloroform, ethyl acetate, and n-butanol). The fractions were analyzed by HPLC-PDA and UHPLC-MS. The ethyl acetate fraction contained mono-and di-glycosides of que...

Haberlea rhodopensis Friv. is unique with its ability to survive two extreme environmental stresses-desiccation to air-dry state and subzero temperatures. In contrast to desiccation tolerance, the mechanisms of freezing tolerance of resurrection plants are scarcely investigated. In the present study, the role of antioxidant defense in the acquisiti...

Citation: Bojilov D., Dagnon S., Kostadinov K., Filipov S. (2020): Polyphenol composition of lettuce cultivars affected by mineral and bio-organic fertilisation. Czech J. Food Sci., 38: 00-00. Abstract: Three types of Lactuca sativa L. plants (green lettuces Batavia cv. Maritima and cv. Winter Butterhead, red lettuce Lolo rosa cv. Tuska) were inves...

ABSTRACT This paper describes an analytical approach for polyphenol components determination in Vernonia amygdalina Del. (VA) using surrogate standards, extracts of green coffee and Achillea asplenifolia 9602, and rutin as an internal standard. HPLC–PDA fingerprint profiles of the polyphenol complex of VA and surrogate standards were developed. By...

Vernonia amygdalina Del. (VA) is one of the most important tropical representatives of family Asteraceaе. The plant is commonly known as “bitter leaf” and is widely consumed as drug and vegetable. The total phenolic content of VA is a subject of many investigations, while the composition of the polyphenol complex is less studied (1). Usually the pl...

Vernonia amygdalina Del. (VA) is one of the most important tropical representatives of family Asteraceaе. The plant is commonly known as “bitter leaf” and is widely consumed as drug and vegetable. The total phenolic content of VA is a subject of many investigations, while the composition of the polyphenol complex is less studied (1). Usually the pl...

This study investigates the relationships between the main polyphenols and DPPH radical scavenging activity (RSA) in extracts from some of the most common wild and cultivated species from the Achillea millefolium group, Mentha, Chenopodium botrys, Clinopodium vulgare and Artemisia vulgaris. Another aspect of the study is the effects of choosing an...

The volatile oils of Chenopodium botrys L. collected in six locations throughout Southern Bulgaria were obtained by hydrodistillation and analyzed by GC/FID and GC/MS. In the essential oils from the aerial parts of C. botrys fifty three components were identified. The chemical composition of investigated oils differed only quantitatively. Most of t...

Due to their beneficial medicinal effects, in recent years there has been an increasing interest in the research of flavonoids identified in plant sources. In the conducted research the flavonoid composition of C. botrys was defined by applying an approach which included different extraction procedures and methods of detection. Primary extraction o...

Maintaining a strong antioxidant system is essential for preventing drought-induced oxidative stress. Thus, in the present study we investigated the role of some non-enzymic and enzymic antioxidants in desiccation tolerance of Haberlea rhodopensis. The effects of high light upon desiccation on antioxidant capacity was estimated by comparing the res...

The volatile oils of Chenopodium botrys L. collected in six locations throughout Southern Bulgaria were obtained by hydrodistillation and analyzed by GC/FID and GC/MS. In the essential oils from the aerial parts of C. botrys fifty three components were identified. The chemical composition of investigated oils differed only quantitatively. Most of t...

Medicinal plants of Achillea millefolium group in Bulgarian wild flora are widely used in both traditional medicine and pharmaceutical, cosmetic and nutritive industries. They are intensively collected from the natural habitats, thus leading to a number of negative effects, such as ecological risk of extinction of native sources, and high heterogen...

This investigation describes the identification and quantification of polyphenols using an approach which includes two extraction procedures, optimization of UHPLC-Orbitrap MS/MS detection and development of HPLC-PDA fingerprint profiles. The polyphenol complex in Mentha, Achillea and Chenopodium botrys, wild and cultivated species was studied. The...

Pattern recognition method (PRM) was applied to gas chromatographic (GC) data for a fatty acid methyl esters (FAME) composition of commercial and laboratory synthesized biodiesel fuels from vegetable oils including sunflower, rapeseed, corn and palm oils. Two GC quantitative methods to calculate individual fames were compared: Area % and internal s...

Tobacco plants (Nicotiana tobaccum L.) (Solanaceae) and tobacco waste have been intensively exploited for production of nicotine, solanesol and protein (1). Oriental tobacco type is characterized with low alkaloid and protein content; hence, it is important to investigate how to utilize this resource. The content of polyphenols in Oriental tobaccos...

The present study reports experimental data on the separation of polyphe-nols in extracts from Oriental and Virginia tobaccos obtained by using macro-porous resin Amberlite XAD7. Additionally, separation conditions for phenolic acids and flavonoids were studied. The polyphenols were purified by adsorp-tion/desorption process based on the different...

In recent years, due to an increase in cancer incidence worldwide, scientists have been turning more and more frequently to searching means of early cancer prevention, as plant foods and the naturally occurring substances in them take a special place among these means. Several studies prove the inhibitory role of natural food products and/or the in...

Monosodum salt of glutamic acid has been approved in Europe as a food additive E 621. It enhances the effect of other taste-active compounds, improving the overall taste of certain foods. There is also an interaction between E 621 and table salt (sodium chloride), and other umami substances such as nucleotides. The aim of the present study was to m...

The influence of polyphenol and essential oil characteristics of Virginia cultivars on the colour of dry tobacco and the aroma of tobacco smoke was studied by applying a chemometric approach. A group of introduced Virginia tobaccos and a local Virginia cultivar V0454 used as a standard were involved in the study. To obtain primary data on the polyp...

The flavonoid-rich natural products exert a wide range of pharmacological properties. This investigation aimed at obtaining extracts from tobacco cultivars and waste enriched with flavonoids and purified from nicotine and phenolic acids, and evaluating their radical scavenging potential. Extraction with a mixture of ethyl acetate-methanol (1:1, v/v...

Leaf samples of different flue-cured Virginia tobacco varieties were analyzed and compared to a standard, the typical American Virginia cultivar K 326. Plants were grown in the Plovdiv region, Bulgaria, under conditions appropriate for Virginia varieties. The tobaccos were characterized by means of high performance liquid chromatography (HPLC) of p...

The color of Oriental tobaccos was organoleptically assayed, and high performance liquid chromatography (HPLC) of polyphenols was performed. The major tobacco polyphenols (chlorogenic acid, its isomers, and rutin), as well as scopoletin and kaempferol-3-rutinoside were quantified. HPLC polyphenol profiles were processed by pattern recognition metho...

Bulgarian specimens of Asteraceae and Solanaceae families are very scarce studied concerning the polyphenolic compounds. The aim of this investigation was to obtain fingerprint chromatographic profiles and to quantify the main polyphenols. HPLC–PDA on Kromasil and Purospher columns was employed for the separation of the components by applying two m...

PURPOSE: The interest in bioflavonoids as antioxidants has increased remarkably over the last decade because of their protective effect against different diseases, including cardiovascular, inflammatory and neurological diseases, as well as cancers. However, the necessity of identifying a better cheaper commercial source of these medicinally import...

The influence of cigarette design on the content of phenols in mainstream tobacco smoke was studied. The most abundant phenols - catechol, hydroquinone, phenol, o-, m- and p-cresol, and resorcinol - were determined by HPLC with fluorescence detection. Hydroquinone and catechol made the most significant contribution to the total content of phenols w...

The influence of cigarette design on the content of phenols in mainstream tobacco smoke was studied. The most abundant phenols - catechol, hydroquinone, phenol, o-, m- and p-cresol, and resorcinol - were determined by HPLC with fluorescence detection. Hydroquinone and catechol made the most significant contribution to the total content of phenols w...

Compounds with reactive oxygen species (ROS)-scavenging ability were studied. High-performance liquid chromatography (HPLC) pattern of polyphenols, contents of proline and carotenoids, and antiradical (AR) capacity were determined. The malonyldialdehyde (MDA) level was also assessed. Tolerant and sensitive cotton genotypes were compared, grown in t...

Levels of valeric acids (isovaleric and 3-methylvaleric) in leaves and smoke of different tobacco types were quantified by capillary gas chromatography (GC) using flame ionization detector (FID). The aroma characteristics of the smoke were scored by sensory evaluation. It was found that leaves of Oriental and burley tobaccos contain higher amounts...

Production of polyphenolic complex compounds in plants contributes to protecting them against herbivores and often determines their forage nutritional value and the insect preference for them. The thrips Frankliniella occidentalis is one of the most important insect pests on vegetable crops in greenhouses on the island of Crete (Greece). We recentl...

Levels of valeric acids (isovaleric and 3-methylvaleric) in leaves of different tobacco types were quantified by CGC (capillary gas chromatography) using flame ionization detector. Their content in the mainstream smoke fraction was also determined. The aroma characteristics of the smoke were scored by sensory evaluation. It was found that leaves of...

Secondary metabolites play a major role in the adaptation of plants to the changing environment and in overcoming stress constraints. This flows from the large complexity of chemical types and interactions underlying various functions: structure stabilizing, determined by polymerisation and condensation of phenols and quinones, or by electrostatic...

The protective role of secondary metabolites against environmental constraints is substantiated by studying various plant – abiotic stress stimuli systems. It was shown that phenylamides, conjugates of hydroxycinnamic acids and polyamines, are induced in tobacco and bean leaves, subjected to water excess and heat shock, respectively. ROS-scavenging...

DAGNON, S. and D. DIMANOV, 2007. Chemometric evaluation of the colour and smoke aroma in oriental tobaccos based on the polyphenol and valeric acid characteristics as influenced by the genotype. Bulg. J. Agric. Sci., 13: 459-466 The influence of polyphenols and valeric acids of Oriental tobacco cultivars on the colour of dry tobacco and the aroma o...

The polyphenol complex of cotton leaves, expressing an abnormal red coloration under abiotic stress, was analysed by using high performance liquid chromatography (HPLQ. Different polyphenol types - cinnamic acid derivatives (C-6-C-3), flavonoids (C-6-C-3-C-6) and anthocyanins (C-6-C-3-C-6(+)) were separated. It was shown that reddening of cotton le...