ОПРЕДЕЛЕНИЕ ОТНОСИТЕЛЬНОЙ АНТИОКСИДАНТНОЙ АКТИВНОСТИ И СОДЕРЖАНИЯ ДУБИЛЬНЫХ ВЕЩЕСТВ В ЛЕКАРСТВЕННЫХ ТРАВАХ, ПРОИЗРАСТАЮЩИХ В РЕСПУБЛИКЕ МОРДОВИЯ

Abstract

Relevance. Medicinal plants can serve as a rich source of natural exogenous antioxidants and antimicrobial agents, such as phenolic acids, flavonoids and tannins. Therefore, the study of extracts of plant raw materials as natural sources of antioxidants is a modern relevant task. Purpose. To study the content of tannins and relative antioxidant activity in 8 types of medicinal plants growing in the Republic of Mordovia. Materials and methods. The raw materials of the aboveground parts of eight medicinal plants growing in the Republic of Mordovia, dried by the air-shadow method, served as the material for the study. The content of tannins was determined by the permanganatometric method. Relative antioxidant activity was determined by phosphorous-molybdenum colorimetric method. Results. The article presents the results of studying the content of tannins (polyphenolic compounds) in 8 types of medicinal plants growing in the Republic of Mordovia, and gives an assessment of their antioxidant activity. It was revealed that the largest amount of tannins is contained in fireweed (Chamerion angustifolium). The highest relative antioxidant activity was noted in an aqueous extract obtained from St. John's wort (Нуреricum реrfоrаtum). Also, extracts of chamomile pharmacy, fireweed, field horsetail showed high relative antioxidant activity. It is established that there is a correlation between the content of tannins and the relative antioxidant activity of the aqueous extracts of the studied medicinal plants. The ratio of antioxidant activity to the content of tannins provides additional data on the contribution of tannins to the antioxidant activity of extracts of the studied medicinal plants. The lower this ratio, the more significant contribution condensed tannins make to the antioxidant activity of the studied extract. If this ratio increases, then the antioxidant activity is determined by other chemicals, including polyphenolic nature, while the contribution of tannins is inversely proportional to the increase in this ratio. By the ratio of antioxidant activity to the content of tannins, we can also judge the qualitative composition of tannins, that is, the ratio of hydrolyzable tannins to condensed ones. Conclusion. The results of this study provide information on the content of phenolic compounds in some types of wild plant raw materials of the Republic of Mordovia and the antioxidant activity of extracts based on them, which will contribute to the use of the studied plants as a potential source of natural antioxidants and tannins. Keywords: antioxidants, relative antioxidant activity, medicinal herbs, phosphorous-molybdenum colorimetric method, tannins.