Component composition and anti-radical activity of catnip extractive substances of the Krasnoyarsk region

The purpose of the study was to obtain aqueous and aqueous-alcoholic extracts of catnip (lemon balm), determine the total content of phenolic compounds and flavonoids in them, analyze the component composition of the obtained extracts by HPLC, and establish the antiradical activity of the extracts. Extractive substances from the feedstock were isolated by extraction with water or water-alcohol mixtures (20, 40, 70 and 95 % alcohol were used) at their boiling point for 1.0 h. The sample of raw materials was 1.0 g, the volume of the solution was 100 ml. After filtration, the resulting solutions were subjected to further studies on the component composition and antiradical activity. It has been established that pure alcohol extracts the minimum amount of substances, the sum of which is 15.4 %. Water-alcohol mixtures extract almost the same amount of substances, which are 19.7-21.3 % based on an air-dry sample of raw materials. The results of the DPPH test, determined by the kinetic method, showed that the ARA value is minimal for alcohol-soluble substances - 2.7 % and increases for water-alcohol extracts from 16.6 % in the case of 70 % extract to 25.2 % for 20 % water-soluble alcohol extract. The maximum value of ARA is typical for aqueous extracts and is 38.5 %. Catnip extracts have low antiradical activity, which does not exceed 50 %. In the extracts obtained, the total content of phenolic compounds was determined (by reaction with the Folin-Ciocalteu reagent), which is 0.09-0.69 wt.% in terms of gallic acid. This value increases evenly when moving from pure alcohol to water. By reaction with aluminum chloride, the total content of flavonoids in the obtained extracts was determined: it is minimal in the case of an alcoholic extract (0.24 % in terms of luteolin) and maximum in the case of an aqueous extract (0.57 % in terms of luteolin). The APA value correlates well with the total content of phenolic compounds (correlation coefficient - 0.9522), while the correlation coefficient of the APA value with the total content of flavonoids is only 0.8809. The HPLC method was used to study the component composition of phenolic compounds in the obtained extracts. The maximum amount of phenolic compounds was found in aqueous extracts, while the minimum amount was found in alcohol extracts. Phenolcarboxylic acids were identified among the components: gallic, caffeylquinic, chlorogenic, caffeic and ferulic. Rutin and some glycosides are present.