Radka Vrancheva

The purpose of the present study was to investigate the antioxidant activity and fructans content in ethanol and water extracts of roots of elecampane (lnula helenium L.), a Bulgarian medicinal plant. The extraction procedure included 95 % (v/v) ethanol extraction and subsequent water treatment. The antioxidant activity was evaluated by severa l reliable methods such as DPPH-, ABTS-, FRAP- and CUPRAC­ assays , as well as by total phenolic content. The total fructans and sugars content were determinated by spectrophotomeric, TLC and HPLC-RID methods. The level of fructans in ethanol extracts was 14.1 g/100 g dry weight, as nystose and 1-kestose were only 0.3 g/100 g dry weight, and 0.5 g/100 g dry weight, respectively. The absence of fructooligosacharides and sugars in water extracts after the ethanol pretreatment was established. Inulin content was evaluated to be 31.2 g/100 g dry weight. The metabolites profile of roots revealed their potential application as radical scavengers due...

The purpose of the present study was to investigate the antioxidant activity and fructans content in ethanol and water extracts of roots of elecampane (Inula helenium L.), a Bulgarian medicinal plant. The extraction procedure included 95% (v/v) ethanol extraction and subsequent water treatment. The antioxidant activity was evaluated by several reliable methods such as DPPH-, ABTS-, FRAP- and CUPRAC-assays, as well as the total phenolic content. In addition, the total fructans and sugar content were determinated by spectrophotomeric, TLC and HPLC-RID methods. The level of fructans in ethanol extracts was 14.1 g / 100 g dry weight, as nystose and 1-kestose were only 0.3 g / 100 g dry weight, and 0.5 g / 100g dry weight, respectively. The absence of fructooligosacharides and sugars in water extracts after the ethanol pretreatment was established. Inulin content was evaluated to be 32 g / 100 g dry weight. The metabolites profile of roots revealed their potential application as radical scavengers due to the presence of polyphenols. Therefore, the root extracts of elecampane could be assumed as a rich source of biologically active substance, in particular dietary fiber with potential prebiotic effect, due to the presence of polysaccharide inulin and fructooligosacharides.

The ultrasonic and microwave assisted extractions of tubers from the Jerusalem artichoke (Helianthus tuberosus
L.) with water, methanol and 70 % ethanol were carried out. The fructan contents (40-60 % dw) were analyzed by the
resorcinol method and TLC analysis. The total phenolic contents and the total flavonoid concentration of the extracts
were estimated, as their antioxidant activities were determinated by DPPH, ABTS, FRAP and CUPRAC methods. The
ethanol extracts obtained by the microwave extraction showed the greatest antioxidant activity, which was probably
due to the highest content of total phenols.

Sucrose esters are nontoxic and biodegradable compounds with a large scaleapplication in food industry as emulsifiers and solubilisator in cosmetics, agriculture and pharmaceuticals. Sucrose esters composed of C6–C12 fatty acids have desirable insecticidal properties against many soft-bodied arthropod pests. Sucrose esters with saturated fatty acids (С6 to С18) and 10-unsaturated undecylenic acid С11 have been synthesized. The obtained sucrose esters were characterized by FT-IR. The antimicrobial activity of some esters of sucrose has been investigated. Sucrolaurate was characterized by well-pronounced antimicrobial activity against fungi Aspergillus and Penicillium, Gram positive bacteria: Bacillus subtilis and Staphylococcus aureus. Unsaturated undecylenic ester of sucrose showed also very well antimicrobial activity against Gram positive bacteria, exhibited inhibition activity against fungi Candida albicans and Gram-negative E. coli, as it also inhibited growth of Pseudomonas aer...

The aim of this study was profiling of primary metabolites of five Bulgarian Fumaria species (F. officinalis L., F. thuretii Boiss., F. kralikii Jord., F. rostellata Knaf. and F. schrammii Velen.) by GC-MS analyses. In polar fractions ten carbohydrates, one polyol, ten amino acids and six organic acids were identified. Apolar (lipid) fractions showed the presence of four free fatty acids, two esters of fatty acids with glycerol and two fatty alcohols. Sucrose and fructose were in the highest relative concentrations of identified carbohydrates. Citric acid was the dominant organic acid in polar fractions of five Fumaria species. Predominant compounds in lipid fractions were palmitic acid and 1-stearoyl-glycerol. Principal component analysis (PCA) of GC-MS data of polar and apolar fractions of five Bulgarian Fumaria species differentiates them in two groups (F. officinalis and F. thuretii; F. rostellata and F. schrammii, respectively), while F. kralikii had phythochemical similarity with plants of both distinguished groups. The obtained results of PCA of primary metabolites could be proposed as chemotaxonomic markers for plants of the genus Fumaria.

A single, selective and rapid HPLC-RID method for determination of inulin, nystose, kestose, sucrose, glucose and fructose in foods has been developed. The best chromatography conditions for separation were obtained on Pb2++ column operating at 85oC, mobile phase deionized water and flow rate 1.0 ml/min. The linearity of the method was in the concentration rate 0.1-10 mg/ml for all analyzed carbohydrates with the correlation coefficient R2 > 0.997. The limit of detection (LOD) and the limit of quantification (LOQ) for inulin, nystose, kestose, sucrose, glucose and fructose have also been defined. The developed method showed very good repeatability and reproducibility (RSD 2-3%) and it was succassfully applied to determine inuline, fructooligosaccharides and sugars in functional food products and the medicinal plant root extract.

The object of our current study is to determinate the biologically active substance presented in the taproots of Bulgarian medicinal plant common chicory (Cichorium intybus L.). The carbohydrate composition, the amount of total phenols, the total flavanoides content and the antioxidant activity in the obtained sequential ethanol and water extracts has been evaluated. The amount of inulin-type fructans was defined by the resorcinol assay. The sugars, fructooligosacharides and inulin contents of the obtained extracts were analyzed by TLC and HPLC-RID methods. The total phenolic and flavonoid quantities were analysed by using Folin–Ciocalteu's and Al(NO 3) 3 reagents, respectively. The antioxidant activity was defined by four method (DPPH, ABTS, FRAP and CUPRAC). The total fructan content in taproots is in range 23 % dw. The presence of monosaccharide glucose, fructose, sucrose and trisaccharides 1-kestose, nystose in the ethanol extracts was observed in the ethanol extracts. The a...

The content of polyphenols in Fumaria officinalis L. and Fumaria thuretii Bioss. from two different
populations, naturally grown in Bulgaria has been studied. Significant differences between concentrations of
main polyphenols (rutin, hyperoside and syringic acid) and antioxidant activity in two different populations of
both analyzed species were not established (RSD 2-14%). Stability of secondary metabolism of F. officinalis
and F. thuretii indicates for genetic stability of Bulgarian Fumaria species growing in different populations.