Three new steroidal sapogenins derived from the roots of Cynanchum otophyllum and their cytotoxic activities

• DOI: 10.1016/j.phytol.2021.08.002
• Publication Date: 2021-08-17T20:07:21Z
• Authors: Xiao-San Li; Xue-Mei Yang; Li Liu; Meng Zhang; Yi-Chang Ren; He-Hui Zhan; Rui Xing; Rong-Rong Luo; Tang-Ji Chen; Jin-Shan Tang
• Keywords: Sapogenin; HeLa; Pregnane

Abstract Three new steroidal sapogenins, 3β,8β,14β-trihydroxycarda-5,20(22)-dienolide (1), (20R)-12β,20-epoxy-3β,8β,14β-trihydroxy-17α-pregn-5-en-17-yl 4-hydroxy-3-methoxybenzoate (2), and 3,20-dioxo-8β,14β,17β-trihydroxy-17α-pregn-5-en-12β-yl 4-hydroxybenzoate (3), along with four known C21-steroidal sapogenins (4-7) were isolated from the hydrolysate of Cynanchum otophyllum roots. Among them, compound 1 harbouring a rare β-OH at the C-8 position in the cardenolide skeleton, was identified for the first time in the genus Cynanchum. Their structures were elucidated via extensive spectroscopic analysis, including UV, IR, HR-ESI-MS, 1D and 2D NMR. Compounds 1-7 were evaluated for their cytotoxic activities against four cancer cell lines (MCF-7, H1299, HeLa, and HepG2). Compound 1 exhibited significant inhibitory effects on the growth of the four cell lines, exhibiting IC50 values ranging from 6.86 to 22.09 μM.