Six new physalins from Physalis alkekengi var. franchetii and their cytotoxicity and antibacterial activity.

Six new physalin steroids, 7β-methoxylisophysalin B (1), 7β-methoxylphysalin C (2), physalin V (3), physalin VI (4), physalin VII (5), isophysalin I (6), together with 20 known physalins (7-26) were isolated from calyces of Physalis alkekengi var. franchetii. Structures of the new compounds were revealed through 1D and 2D NMR and mass spectroscopic methods. Compounds 1-26 were evaluated for cytotoxicity against human HL-60, SMMC-7721, A-549, MCF-7 and SW-480, and the results indicated that compounds 8, 11, and 14 displayed potent cytotoxicities (IC50<5μM) in vitro. Further antibacterial assay indicated that compounds 8, 14, and 19 showed high antibacterial activities against Bacillus subtilis and Escherichia coli.