Identification of betulin in the bark of aspen by liquid chromatography

Aim – screening of biologically active substances of common aspen bark, detection and identification of betulin in the bark of aspen by liquid chromatography. Material and methods. The object of the study is dried and crushed samples of aspen bark. Qualitative analysis of coumarins, flavonoids, phenolic compounds and saponins was carried out using qualitative chemical reactions for the indicated groups of biologically active substances. Alcohol extraction and purified betulin fraction were used for chromatography. Chromatography was performed using an UltiMate 3000 liquid chromatograph. To separate the components, a column with a length of 250 mm and an inner diameter of 4.6 mm filled with octadecylsilyl silica gel for chromatography with a particle size of 5 microns was used. A mixture of acetonitrile-water 90:10 (v/v) in the isocratic mode was used as the mobile phase. Detection was performed at a wavelength of 206 nm. Results. Using the method of qualitative chemical analysis, coumarins, flavonoids, phenolic compounds and triterpene saponins were found in samples of common aspen bark. Peaks with a retention time of about 7.5 minutes with similar spectral characteristics were found on all chromatograms. This allows us to conclude that the alcohol extraction of aspen bark and the isolated, purified fraction contain significant amounts of betulin. The betulin content in the alcohol extraction (n=3) was 0.77±0.04%. Conclusion. 1. Using the method of qualitative chemical analysis, coumarins, flavonoids, triterpene saponins and phenolic compounds were found in samples of common aspen bark. 2. Betulin was detected and identified by liquid chromatography in the bark of aspen. 3. Betulin is recommended as an analytical marker in the identification of aspen bark by liquid chromatography. 4. The prospects of using liquid chromatography for the identification and assessment of the degree of purification of betulin during its isolation from the bark of aspen are shown.