Features of the Accumulation of Flavonoids in Medicinal Plant Raw Materials of the Synanthropic Flora of Rostov Region

Inconsistencies in literature data on the environmental features of the biosynthesis of polyphenol biologically active substances in medicinal plant raw materials were found particularly for flavonoids, which are important secondary metabolites that significantly contribute to the response to abiotic and anthropogenic stress. The goal of the study was to elucidate features of the accumulation of flavonoids in medicinal plant raw materials of the synanthropic flora of Rostov Region using Morozovsky District as an example. The accumulation of flavonoids in samples of knotgrass herb ( Polygonum aviculare L.), wormwood ( Artemisia absinthium L.), and common yarrow ( Achillea millefolium L.) of the synanthropic flora of Rostov Region was characterized with a significant variability depending on the harvesting site. Samples of medicinal plant raw materials collected in several urbocenoses displayed induced flavonoid accumulation as compared with samples from control territories. This could be explained by activation under the anthropogenic load of the key enzyme for flavonoid biosynthesis (phenylalanine ammonia lyase), which is highly induced by stress. However, samples collected in areas of significant anthropogenic impact (mainly along a category IA highway or railroad trunkline) were characterized by a reduced content of flavonoids. This was probably due to excessive environmental pollution going beyond the endurance of the species and causing suppression of the enzyme systems.