Physalins and withanolides from the fruits of Physalis alkekengi L. var. franchetii (Mast.) Makino and the inhibitory activities against human tumor cells

The fruits of Physalis alkekengi L. var. franchetii (Mast.) Makino have been used in Chinese medicine for thousands of years because of its significant biological activities. A comprehensive phytochemical study of the chemical constituents of the fruits resulted in the isolation of three new steroids (1–3) as well as seven known steroids (4–10). Their structures were identified by the extensive analyses of 1D and 2D NMR, IR, HR-ESI-MS and other techniques. Compound 4 (physalin B) showed the most significant cytotoxic activities against HeLa human cervical, SMMC-7721 human hepatoma, and HL-60 human hepatoma tumor cell lines, with the IC50 values of 0.51, 0.86 and 1.12 μM, respectively. Compounds 1, and 5–9 showed potent cytotoxic activities.