Two new C₂₁ steroidal glycosides isolated from Cynanchum komarovii

The present study was designed to further investigate the C₂₁ steroidal glycosides in Cynanchum plants. Two new steroidal glycosides based on a 13, 14:14, 15-disecopregnane-type aglycone, komaroside P ( 1 ) and komaroside Q ( 2 ), together with three known compounds ( 3 - 5 ) were isolated from the whole herbs of Cynanchum komarovii. The aglycones of compounds 1 and 2 were two new disecopregnane. Their structures were elucidated on the basis of 1D, 2D NMR spectroscopic data and acid hydrolysis. All the compounds ( 1 - 5 ) showed potent inhibitory activities against human leukemia cell lines (HL-60) with IC₅₀ values ranging from 16.6 to 26.3 μmol·L^-1, compared to the positive control 5-fluorouracil (6.4 μmol·L^-1).