LAUSR

From the leaves of the black poplar (Populus nigra L., Salicaceae family) there were for the first time isolated rutin (quercetin-3-O-rutinoside), calendoflavobioside (quercetin-3-O-neohesperidoside) (flavonoids) and ferulic acid (phenylpropanoid) by using of liquid column chromatography. The chemical structures of the isolated compounds there were elucidated by means of 1H-NMR-, 13C-NMR-, UV-spectroscopy, mass spectrometry and results of chemical transformations. The isolated flavonoids are the dominant phenolic components of the raw material of the investigated plant. It was determined, that the isolated flavonoids cause the spectral characteristics of the UV spectra of the water-ethanolic extract from the Populus nigra leaves. It was substantiated the expediency of the estimation of the total flavonoids in the leaves of Populus nigra calculated on rutin. As results there was development the method of the quantitative determination of the total flavonoids in the leaves of Populus nigra by the using of the differential spectrophotometry at an analytical wavelength of 414 nm. It was determined that the content of the total flavonoids in the raw materials of the studied plant varies from 2.04±0.09% to 2.99±0.11%. The relative degree of the determination of the total flavonoids in the leaves of black poplar in developed method with confidence probability 0.95 is no more than ± 6.26%.