STUDY OF THE FLAVONOID COMPOSITION AND BIOLOGICAL ACTIVITY OF HAWTHORN`S LEAVES CRATAEGUS PONTICA

Abstract

The results of studies of the content of polyphenolic compounds and their antioxidant activity in the Pontic hawthorn plant Crataegus pontica K.Koch., growing in the mountainous regions of the Tashkent region of the Republic of Uzbekistan are presented. The collection of raw materials took place in the spring at the beginning of October 2019 and at the end of April 2020. The conditions for the isolation of polyphenolic compounds were selected under various conditions. It was shown that the optimal content of polyphenols is extracted with 70% acetone, followed by fractionation of the aqueous residue with ethyl acetate and precipitation with hexane. It was shown that in the plants harvested in spring, the amount of polyphenols was 4.28%, and the collected volume was 2.6%, of the air-dry mass of the raw material. Chromatographic methods (BC and TLC) revealed that the composition of plant leaves collected in spring contains more polyphenols than those collected in autumn. This plant contains compounds belonging to the class of flavonols, phenolic acids and flavan-3-ols. Polyphenols were identified by rutin, quercetin, quercetin-3-O-β-galactoside, catechin, and gallic acid by BC and TLC methods. The antioxidant activity of the sum of polyphenolic compounds was studied in the model of lipid peroxidation (LPO) in rat liver mitochondria. It was found that polyphenols have a protective effect on mitochondria, a reduced damaging effect of Fe2+ / ascorbate and antioxidant activity depends on the concentration of the studied polyphenolic substances. The introduction of rutin into the incubation medium in 5 μM medium inhibits LPO processes by 32.0%, and at 10 μM – by 85.9% and in 20 μM – by 96.8%, compared with the control.