The content of betulin in the bark of birch trees in different seasons depending on collection and substance solvent

The paper presents experimental data on the use of different solvents (ethanol, isopropanol, hexane, water) to obtain samples of betulin from birch bark, taken from three habitats: Achitskogo district of the Sverdlovsk region, near the Student village 58 km from the city of Ekaterinburg, the Park down the street Pervomayskaya, Yekaterinburg. On the basis of the results obtained in the study are recommendations for selection of sites taking into account environmental conditions and the time of sampling.