Two new megastigmane glycosides, physanosides A and B, from Physalis alkekengi L. var. franchetii, and their effect on NO release in macrophages

Two new megastigmane glycosides, physanosides A and B (I and 2, resp.), were isolated from Physalis alkekengi L. var. franchetii, together with four known compounds (6S,9R)-roseoside (3), (6S,9S)-roseoside (4), (6R,9S)-3-oxo-alpha-ionol beta-D-glucopyranoside (5), and citroside A (6). Their structures were elucidated on the basis of physicochemical evidence, in-depth NMR spectroscopic analysis, high-resolution mass spectrometry, and CD spectroscopy, and their inhibitory effect on NO production was also examined. Compounds 2 and 3 exhibited strong inhibition on lipopolysaccharide-induced NO release by macrophages with IC(50) values of 9.93 and 7.31 mu m, respectively.