Eight new C21-steroidal glycosides from the roots of Cynanchum auriculatum

Abstract

Eight new C₂₁-steroidal glycosides (1–8) and fourteen known analogs (9–22) were isolated from the roots of Cynanchum auriculatum Royle ex Wight (Asclepiadaceae). The structures of the new compounds were elucidated on the basis of their IR, HR-ESI-MS, and NMR data. The cytotoxicities of compounds 1–22 were evaluated against two prominent human cancer cell lines, SW480 and MDA-MB-231, leading to preliminary structure-activity relationships (SARs). Notably, compounds 1, 5, 8, 10, and 22 exhibited significant cytotoxic activity against both cell lines, with IC₅₀ values ranging from 8.76 ± 1.36 to 17.90 ± 1.77 μM for SW480 and from 10.97 ± 1.73 to 12.07 ± 1.13 μM for MDA-MB-231.