Six new C-21 steroidal glycosides (1-6) were separated from the root of Dregea sinensis Hemsl. and their structures were elucidated using extensive nuclear magnetic resonance, mass spectrometry, and infrared spectral analyses. Isolated compounds were evaluated for antitumor activity, which showed that compound 3 had moderate activity in Jurkat cells (IC50 19.54 ± 0.91 μM), and compounds 1-4 had significant effects against IL-2R and TNFR2 (IC50 1.518 ± 0.06 μM to 5.9 ± 0.07 μM).
Keywords: C-21 steroidal glycosides; Dregea sinensis; anticancer activity; structure–activity relationship.