Recovery of lipophilic compounds of Vincetoxicum species by supercritical carbon dioxide extraction

In this study, the dried herb of three Vincetoxicum species was subjected to supercritical carbon dioxide (SC-CO2) extraction for the recovery and characterisation of lipophilic compounds. The differences in extraction yield were not remarkable for the analyzed species; however, the effect of herb harvesting time at different year was quite significant. Two times higher yields of lipids were obtained from the plants collected in September 2020 compared to those collected in June 2022, e.g., from 1.39 to 3.01%. Linoleic, linolenic, oleic and palmitic acids were the major fatty acids in the extracted oils. 13-sitosterol was the major phytosterol (from 4.84 to 10.74 mg/g), followed by stigmasterol, while vitamin E (alpha-tocopherol) was the dominant tocopherol in Vincetoxicum species extracts. CO2 extracts had similar antioxidant capacity and total phenolic content determined by different methods. Isovaleric acid, butyrolactone, hexanoic acid were the major volatile components identified in almost all plants extracts, however based on the integrated peak area significant quantitative variations were observed for different species and harvesting period (year). In conclusion, this study is the first report on lipophilic fraction of Vincetoxicum species recovered by SC-CO2, which demonstrates the presence of various bioactive components in the studied botanicals.