Ivanka Dimitrova-Dyulgerova

Prof. Dr. Ivanka Dimitrova-Dyulgerova

orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 March 2022 in Plants
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ISIlia Zhelev Slavov
Ilia Zhelev Slavov
ZPZhanina Stoyanova Petkova
Zhanina Stoyanova Petkova
IKIliana Kostova
Iliana Kostova
SDStanka Todorova Damyanova
Stanka Todorova Damyanova
ASAlbena Stoyanova
Albena Stoyanova
ASAmany Sayed
Amany Sayed
The chemical composition of Vitex agnus-castus L. (Verbenaceae family) fruits, collected from two regions in Bulgaria (south-central and north-east Bulgaria), was investigated. The content of proteins (5.3–7.4%), carbohydrates (73.9–78.8%), fiber (47.2–49.9%), ash (2.5–3.0%), essential oils (0.5%), and vegetable oil (3.8–5.0%) were identified in the fruits. The composition of the essential oils (EOs) of Vitex fruits from both regions was determined; the main compounds were 1,8-cineole (16.9–18.8%), α-pinene (7.2–16.6%), sabinene (6.7–14.5%), and bicyclogermacrene (7.3–9.0%), but significant differences in the quantitative and qualitative composition of EOs between the regions were found. The EOs of plants from north-east Bulgaria demonstrated antimicrobial activity against the pathogenic species Salmonella abony, Staphylococcus aureus, and Bacillus subtilis, but the Gram-negative bacteria Esсherichia coli and Pseudomonas aeruginosa exhibited resistance to the oil. Linoleic acid predominated in vegetable oil from both regions, followed by oleic acid. β-sitosterol and γ-tocopherol were the main components in the sterol and tocopherol fraction of the lipids. Phosphatidic acids were the main components in the vegetable oil from north-east Bulgaria, while in the vegetable oil from south-central Bulgaria, all phospholipids were found in almost the same quantity. Overall, significant differences were observed in the chemical composition (proteins, carbohydrates, ash and moisture) of the fruits from the two regions of Bulgaria, as well as in the content of the main components of their essential and vegetable oils.

17 February 2023 in Plants
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TATsvetelina Georgieva Andonova
Tsvetelina Georgieva Andonova
YMYordan Muhovski
Yordan Muhovski
ISIlia Zhelev Slavov
Ilia Zhelev Slavov
RVRadka Vrancheva
Radka Vrancheva
Vasil GeorgievVasil Georgiev
Vasil Georgiev
IDIvanka Dimitrova-Dyulgerova
Ivanka Dimitrova-Dyulgerova
Invasive species as sources of natural components are of increasing interest for scientific research. This is the case of Ailanthus altissima, which belongs to the top 100 of the most dangerous invasive plant species in Europe, and which is the subject of the present study. The purpose of the research was to analyze the main phenolic compounds in the flowers, leaves, and stem bark of A. altissima and determine the DNA-protective and antioxidant potential of their ethanolic extracts. HPLC profiling revealed the presence of 6 flavonoids and 10 phenolic acids, of which 15 were found in flowers, 14 in leaves, and 11 in the stem bark. Rutin (5.68 mg/g dw in flowers), hesperidin (2.67 mg/g dw in leaves) and (+)-catechin (2.15 mg/g dw in stem bark) were the best-represented flavonoids. Rosmarinic (10.32 mg/g dw in leaves) and salicylic (6.19 mg/g dw in leaves) acids were predominant among phenolic acids. All plant extracts tested showed in vitro antioxidant activity (determined by DPPH, ABTS, FRAP, and CUPRAC assays) and DNA-protection capacity (assay with supercoiled plasmid DNA—pUC19). The highest antioxidant activity was recorded in the flower parts (in the range from 661 to 893 mmol TE/g dw), followed by the leaves. A DNA protective potential for A. altissima leaf and flower extracts has not been established to date. In addition, the main microscopic diagnostic features of studied plant substances were described, with data for the flower parts being reported for the first time. The present study proves that A. altissima could be a natural source of DNA protection and antioxidants.

18 December 2023 in Plants
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ZPZhanina Stoyanova Petkova
Zhanina Stoyanova Petkova
OTOlga Teneva
Olga Teneva
GAGinka Antova
Ginka Antova
MAMaria Angelova-Romova
Maria Angelova-Romova
Gana GechevaGana Gecheva
Gana Gecheva
IDIvanka Dimitrova-Dyulgerova
Ivanka Dimitrova-Dyulgerova
Hypnum cupressiforme Hedw. is the main species for Moss surveys (ICP Vegetation programme) in Southeastern Europe and is widely distributed in the region. In addition to their biomonitoring role, mosses are applied in some countries as a traditional medicine for the treatment of eczema, cuts, burns, eye diseases, etc. Therefore, the chemical and lipid composition of the moss H. cupressiforme is of interest to establish their possible application in different fields. The chemical composition of the moss was examined regarding total lipids, proteins, carbohydrates (i.e., fibres), ash, and moisture content. The main lipid-soluble bioactive components were determined as sterols, tocopherols, phospholipids and fatty acids. The major fatty acids were linoleic (14.9%), oleic (13.8%), palmitic (12.5%) and α-linolenic (11.3%) acids. Unsaturated fatty acids (56.4%) prevailed in the glyceride oil, in which the polyunsaturated ones constituted 32.5%. The lipid indices (atherogenicity, thrombogenicity, hypocholesterolemic/hypercholesterolemic ratio, peroxidability, and oxidation stability index) were also theoretically calculated based on the fatty acid composition of the moss lipids to establish their health benefits and the rate of oxidation. The primary results of this study revealed H. cupressiforme to be a promising alternative source of bioactive compounds that could be implemented in supplements with health-promoting effects.

13 June 2022 in Antioxidants
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TATsvetelina Georgieva Andonova
Tsvetelina Georgieva Andonova
YMYordan Muhovski
Yordan Muhovski
RVRadka Vrancheva
Radka Vrancheva
ISIlia Zhelev Slavov
Ilia Zhelev Slavov
EAElena Apostolova
Elena Apostolova
IDIvanka Dimitrova-Dyulgerova
Ivanka Dimitrova-Dyulgerova
Interest in plant extracts as a natural source of antioxidants has grown significantly in recent years. The tree species Koelreuteria paniculata deserves attention due to its wide distribution, good adaptability, and growth to the degree of invasiveness in a number of European countries. The purpose of the present study was to analyze flavonoids and phenolic acids of the ethanol extracts from aerial parts of K. paniculata and to screen their antioxidant and DNA-protective activity. HPLC profiling revealed the presence of five flavonoids, with rutin (4.23 mg/g DW), hesperidin (2.97 mg/g DW), and quercetin (2.66 mg/g DW) as the major ones in the leaves, and (−)-epicatechin (2.69 mg/g DW) in the flower buds. Among the nine phenolic acids identified, rosmarinic, p-coumaric, salicylic, vanillic, and gallic acids were the best represented. All the extracts tested showed in vitro antioxidant activity that was determined by DPPH, ABTS, FRAP, and CUPRAC assays. The highest activity was recorded in the flower parts (in the range from 1133 to 4308 mmol TE/g DW). The DNA-protective capacity of the flower and stem bark extracts from the in vitro nicking assay performed, as well as the main diagnostic microscopic features of the plant substances, are given for the first time. According to the results obtained, the aerial parts of K. paniculata could be valuable sources of natural antioxidants.

1 January 2015 in Pharmacognosy Magazine
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IZIliya Zhelev
Iliya Zhelev
IDIvanka Dimitrova-Dyulgerova
Ivanka Dimitrova-Dyulgerova
Dasha MihaylovaDasha Mihaylova
Dasha Mihaylova
Phcog Mag, Official publication of Pharmacognosy Network Worldwide, India

3 October 2024 in Antioxidants
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TATsvetelina Georgieva Andonova
Tsvetelina Georgieva Andonova
YMYordan Muhovski
Yordan Muhovski
EAElena Apostolova
Elena Apostolova
SNSamir Naimov
Samir Naimov
SMSilviya Mladenova
Silviya Mladenova
IDIvanka Dimitrova-Dyulgerova
Ivanka Dimitrova-Dyulgerova
Nowadays, interest in natural antioxidants (especially phenolics) for the prevention of oxidative stress-related diseases is increasing due to their fewer side effects and more potent activity than some of their synthetic analogues. New chemical and pharmacological studies of well-known herbal substances are among the current trends in medicinal plant research. Meadowsweet (Filipendula ulmaria) is a popular herb used in traditional medicine to treat various diseases (including rheumatic-, inflammatory- and tumor-related disease, etc.). The dry tincture of Filipendulae ulmariae herba, collected from the Bulgarian flora, was analyzed using the HPLC method and bioassayed for antioxidant, antiproliferative and DNA-protective activities against oxidative damage. The HPLC phenolic profile showed 12 phenolics, of which salicylic acid (18.84 mg/g dry extract), rutin (9.97 mg/g de), p-coumaric acid (6.80 mg/g de), quercetin (4.47 mg/g de), rosmarinic acid (4.01 mg/g de) and vanillic acid (3.82 mg/g de) were the major components. The high antioxidant potential of the species was confirmed by using four methods, best expressed by the results of the CUPRAC assay (10,605.91 μM TE/g de). The present study reports for the first time the highly protective activities of meadowsweet dry tincture against oxidative DNA damage and its antiproliferative effect against hepatocellular carcinoma (HepG2 cell line). Meadowsweet dry tincture possesses great potential to prevent diseases caused by oxidative stress.