Dimitrina Zh. Zheleva-Dimitrova

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Thirteen Hypericum species growing in Bulgaria were investigated for free radical-scavenging activity, antioxidant activity, total tannins and total flavonoids contents. Methanolic extracts from the Hypericum species were analyzed for radical scavenging and antioxidant activities using DPPH-, ABTS- free radicals, total antioxidant activity and inhibition of(More)
Oxidative stress is implicated in the pathogenesis of different human diseases: Alzheimer, Parkinson, Huntington, amyotrophic lateral sclerosis (Lou Gehrig's disease), Down's syndrome, atherosclerosis, vascular disease, cancer, diabetes mellitus type 1 and type 2, age - related macular degeneration, psoriatic arthritis. The aim of current study is to(More)
BACKGROUND Amorpha fruticosa L. and Phytolacca americana L. are native plants for North America, but invasive for Central Europe and the Mediterranean areas. Previous investigation reported DPPH radical scavenging activity of A. fruticosa seeds from Mississippi river basin and P. americana berries from Iran. The aim of the present study was to investigate(More)
Two cytotoxic constituents, namely elegaphenone and 7-epi-clusianone, were isolated from the aerial parts of Hypericum elegans Stepan ex Willd. Elegaphenone was identified as (E)-(2-(3,7-dimethylocta-2,6-dienyloxy)-4,6-dihydroxyphenyl)(phenyl)methanone by means of spectral evidence. Both compounds showed prominent cytotoxicity on HD-MY-Z, K-562 and KE-37(More)
Piperazine nucleus is one of the most important heterocyclic systems exhibiting remarkable pharmacological activities. Thus, in the current study six new aryl/aralkyl substituted piperazine derivatives, containing methylxanthine moiety were synthesized and their structures were confirmed by IR and 1 H NMR analysis. All compounds were in vitro screened for(More)
Some of the environmental toxicants acting as endocrine disruptors have been associated with health hazards in human and wildlife by modulating hormonal actions. Atrazine, a strong endocrine disruptor, induces detrimental effects on gonads in male and female, and causes impairment of fertility and developmental problems as well as sex alterations. Atrazine(More)
INTRODUCTION Arnica montana flowers have a long history as herbal medicines for external use on injuries and rheumatic complaints. OBJECTIVE To investigate Arnicae flos of cultivated accessions from Bulgaria, Poland, Germany, Finland, and Pharmacy store for phenolic derivatives and sesquiterpene lactones (STLs). MATERIALS AND METHODS Samples of Arnica(More)
Elegaphenonoside, a new benzophenone O-rhamnoside, together with two known benzophenone O-glycosides, namely hypericophenonoside and neoannulatophenonoside, were isolated from the aerial parts of Hypericum elegans Stephan ex Willd. The structure of the new compound was established as 3',5',6-trihydroxy-4-methoxybenzophenone-2-O-alpha-L-rhamnopyranoside by(More)
BACKGROUND Haberlea rhodopensis Friv. (Gesneriaceae) is a rare poikilohydric endemic and preglacial relict growing in Balkan Peninsula. Previous investigations demonstrated strong antioxidant, antimicrobial and antimutagenic potential of alcoholic extract from the plant. OBJECTIVE The isolation of known caffeoyl phenylethanoid glucoside - myconoside and(More)
The occurrence of three known benzophenones, namely annulatophenonoside, acetylannulatophenonoside and annulatophenone as well as a flavonol O-glycoside guajaverin in the aerial parts of Hypericum maculatum Crantz was established. In addition, hyperoside, isoquercitrin and miquelianin were isolated from this plant, as well. Radical scavenging and(More)