The study of flavonoids accumulation by the herb Polygonum aviculare of the synanthropic flora of the Rostov Region

Aim to study the flavonoid accumulation peculiarities in the birdweed herb (Polygonum aviculare) harvested in the Rostov Region. 
Material and methods. Several raw material sampling areas in the Morozovsky District of the Rostov Region were selected for the study. The birdweed grass was harvested near a major highway M-21 (IA category), a low-speed road (IV category) with little traffic, and a railway line of the North Caucasus Railway. The sampling was conducted at distances from 1 to 300 meters at 100-meter intervals. The choice of harvesting areas was determined by the lack of accurate and reliable information on the accumulation of biologically active substances in the raw material depending on the distance from highways and railroads. In addition, we harvested the birdweed grass in ecologically clean areas far away from the objects of anthropogenic impact (control areas). 
Results. The study of the plant raw material harvested along a low-speed road with little traffic revealed a direct correlation in the reduction of flavonoid content, in terms of avicularin, with increasing distance from the road. The results obtained in the study of samples harvested along the highway M-21 and the railway line also reflected the dependence of the induction of phenolic compounds in the raw material on its growth near the highway. However, in conditions of remoteness from a source of anthropogenic impact on 200 meters and more, there was a decrease in the content of flavonoids, which was approximately equal to their content in the raw material harvested in the control areas. 
Conclusion. A moderate anthropogenic impact, which is characterized by the release of various ecotoxicants into the environment, can induce the biosynthesis of flavonol compounds.