Comparative phytochemical study of white poplar (Populus alba L.) and black poplar (Populus nigra L.)

Aim – to conduct a comparative phytochemical study of leaves, wood buds, shoots, bark of two representatives of the genus poplar – white poplar and black poplar. Material and methods. For the experiment, we have chosen leaves, wood shoots, buds, bark of black poplar (Populus nigra L.), white poplar (Populus alba L.) and also reference standards (RS). The thin-layer chromatography was carried out on the plates Sorbfil-PTSH-AF-A-UV in the systems n-butanol-acetic acid-water (4:1:2) and chloroform-ethyl alcohol-water (25:18:2). The spectrophotometry was carried out on a Specord 40 spectrophotometer (Analytik Jena) in cuvettes with a layer thickness of 10 mm in the wavelength range from 190 to 500 nm. The comparison solution was ethyl alcohol of 96% concentration. Results. In the water-alcohol extracts of the leaves of poplar species the presence of rutin and other phenolic compounds was detected. Pinostrobin and pinocembrin were observed in wood shoots, buds and bark of the plants. The bathochromic shift of the long-wavelength line in the ultraviolet spectra of the studied extracts solutions indicated the presence of flavonoids. Conclusion. In all cases, flavonoids made the greatest contribution to the absorption curves of the spectra, in particular: flavanones (pinocembrine, pinostrobin, and others), and phenylpropanoids (caffeic acid and other cinnamic acids). The leaves, wood shoots and buds of the plants contained substances of a phenolic nature, including flavonoids. The composition of the bark of the white poplar was mainly represented by phenolic compounds – phenylpropanoids and simple phenols.