THE CONTENT OF SECONDARY METABOLITES IN THE ARIL OF TAXUS CANADENSIS MARSHALL PLANTS, WHICH DETERMINE ITS BIOLOGICAL ACTIVITY

Introduction. Taxus сanadensis Marshall are the shortest shade–tolerant and frost-resistant representatives of relict gymnosperms belonging to the genus Taxus. Valuable yew wood is able to accumulate unique secondary metabolites that have no synthetic analogues and are successfully used in the treatment of oncological diseases. It is known that secondary metabolites of plants play a direct regulatory role in the physiological and biochemical processes of the plant organism. Therefore, at the first stage of our research, it is necessary to determine the features of formation and localization of secondary compounds of phenolic and terpenoid nature with high biological activity in the arils of seeds of plants of the genus Taxus. The purpose of the study to investigate the features of formation and localization of secondary compounds of phenolic and terpenoid nature with high biological activity in the arils of seeds of plants of the genus Taxus and to determine their cytotoxic effect. Material and methods. The object of the study was the seed-cones of Canadian yew (Taxus canadensis), collected during the growing season (June-October) from plants introduced in the Moscow region. The localization of phenolic compounds was studied in the appendage (aril) of yew seeds collected at different stages of formation and maturation. To do this, histochemical methods were used: to identify the amount of phenolic compounds, the material was stained with 0.08% Fast Blue reagent raster, and a reaction with vanillin reagent in hydrochloric acid vapor was used to study the localization of flavans (catechins and proanthocyanidins). The localization of terpenoids was determined using NADI reagent. The content of the sum of soluble phenolic compounds, flavans and flavonols in the extracts was determined by the spectrophotometric method. The cytotoxic properties of the extracts were studied using an MTT test. Results. Plants of the genus Taxus are characterized by the formation of an overgrown fleshy appendage – aril rich in metabolites of primary and secondary origin. It was shown that, during the entire growing season, and at various stages of aril development, the studied parts of the plant have a high ability to biosynthesize secondary compounds of phenolic and terpenoid nature, which were localized in the epidermal cells of the apex and the underlying layer of parenchyma cells, the cells of the basal part of the aril, and also in some idioblasts located in the parenchyma. Flavones are the dominant components of the phenolic complex of aril. localized Conclusion. Extracts from the vegetative organs of yew plants have pronounced cytotoxic activity, and extractive substances from aril have shown no cytotoxic effect, which indirectly indicates its low toxicity.