Abstract
The bioassay-guided phytochemical study of an ethnic medicinal plant Aspidopterys obcorda ta Hemsl. var. obcordata results in the isolation of eight new polyoxypregnane derivatives, named aspidatasides A-H (1-8), along with ten known analogs (9-18). The series polyoxypregnane derivatives were screened for their cytoxic activity against HL-60 cells, and compound 2 showed the highest potency with an IC(50) 8.03 μM. Preliminary structure-activity relationship studies displayed that the sugar chain and double bond could notably impact their biological activity.