Steroids and flavonoids from Physalis alkekengi var. franchetii and their inhibitory effects on nitric oxide production.

Four new steroidal compounds possessing a rare 13,14-seco-16,24-cycloergostane skeleton, physalin Y ( 1), physalin Z ( 2), physalin I ( 6), and physalin II ( 7), were isolated from the 80% EtOH extract of calyces from Physalis alkekengi var. franchetii together with 11 known steroids ( 3- 5 and 8- 15) and eight flavonoids ( 16- 23). The structures of the new compounds were elucidated primarily on the basis of 1D and 2D NMR and mass spectroscopic studies. The relative configuration of the 3-OH group of 3, 4, and 5 was also established or re-established. The inhibitory effects of compounds 1- 23 on nitric oxide production in lipopolysaccaride-activated macrophages were evaluated.