Fourteen new polyhydroxylated pregnane
glycosides, cissasteroid A-N (1-14), and five known analogues (15-19), were isolated from the dried whole plant of Cissampelos pareira var. hirsuta. Their structures and stereochemistry were elucidated by extensive spectroscopic data, chemical hydrolysis, and ECD measurements. All the compounds were tested for their cytotoxicity against five human
cancer cell lines, and inhibitory activity against NO release in LPS-induced RAW 264.7 cells. Compared with
cisplatin, compound 7 showed more potent cytotoxicities against the HL-60, A549, SMMC-7721, MCF-7, and SW480 cell lines, with IC50 values of 2.19, 14.38, 2.00, 7.58, and 7.44 μM, respectively. The preliminary study of structure-activity relationship indicated that
benzoic acid esterification at C-20 may have a negative effect on the cytotoxic activity of polyhydroxylated pregnane derivatives in these five human
cancer cell lines. These results revealed the potential of compound 7 as an ideal antitumor lead compound.