ИСТИНА

Ginseng based medicines help to build up general vitality and increase resistance to physical, chemical and biological stress. As a result ginseng based products are widely used as biologically active dietary supplements. Ginsenosides are considered the main active principles of the traditional medicine “ginseng” but the chemical composition of different ginseng based formulations, food products and supplements is not fully investigated. Objective: The goal of this study was to obtain significant amounts of the bioactive compounds from ginseng oolong tea for their further structural analysis using NMR and HPLC-MS/MS. Methods: Ultra-sound assistant extraction with methanol and water was performed. Dried extract was dissolved in water. Ether was used for liquid-liquid extraction of impurities. In the next step the compounds of interest were extracted with n-butanol and the extract was dried and dissolved in methanol. HPLC isolation was carried out using a reversed-phase chromatography with SB-C18 sorbent. For compounds identification, electrospray ionization and quadrupole/linear ion trap mass-spectrometer (ESI-LITMS), 13C and 1H NMR were used. Results: Ginseng oolong extract HPLC-LITMS analysis in positive and negative detection modes have showed the group of peaks which mass-spectra were close to those of ginsenosides from the roots of Panax ginseng. Obtained mass-spectra have shown new fragmentation pattern of the unknown sapogenin. The composition of the sugar chains was also determined using MS/MS data. The comparison of the obtained mass-spectra and mass-spectra of standard protopanaxadiol, protopanaxatriol, ocotillol-type ginsenosides was made. HPLC-MS based separation and collection of the saponin fraction containing one of the compounds in the selected ion monitoring mode was done. Dried extract was dissolved in pyridine-d5:D2O mixture (7:1). Different NMR experiments including 1H-1H COSY и 1H-13C HMBC were conducted. Obtained NMR data was analysed to confirm proposed new sapogenin structure. Conclusion: The structures of several compounds present in ginseng oolong were proposed on the basis of HPLC-MS/MS data and the NMR analysis data of the isolated saponin fraction have confirmed the sapogenin structure of these compounds.