Two new furostanol saponins from Reineckia carnea

Two new furostanol saponins, (25S)-22-O-methoxy-5β-furostan-1β,2β,3β,4β,5β,6β,22ξ, 26-octaol-26-O-β-d-glucopyranoside (1) and (25S)-22-O-methoxy-26-O-β-d-glucopyranosyl-5β-furostan-1β,2β,3β,22ξ, 26-pentol-1-O-β-d-xylopyranoside (2) were isolated from the whole plant of Reineckia carnea (Andr.) Kunth along with seven known compounds (3-9). The structures of the new saponins were elucidated by detailed analysis of their NMR spectra, chemical evidence and comparison with spectral data of known compounds. Based on the chemical structural characteristics, functional group substitution rules, sugar chain connection methods of the two new furostanol saponins, as well as the natural biogenic synthesis and evolution rules of steroid saponins, an in-depth analysis of the possible biogenetic relationship were conducted. Compound 4, 6, and 9 were obtained for the first time from the Reineckia genus. In addition, the cytotoxic activities in U87-MG and MCF-7 tumor cells of the isolated compounds (1-9) were determined by the MTT method. The results showed that Compound 4 had inhibitory effects on U87-MG cells and MCF-7 cells, with IC₅₀ values of 35.21 μM and 28.26 μM, respectively.