New anti-inflammatory withanolides from Physalis pubescens fruit

Physalis pubescens L. is a medicinal plant widely cultivated in northeast of China. Investigation on the extract of P. pubescens fruit led to the isolation and identification of four new withanolides, namely, physapubescins J-M (1, 2, 4 and 5), together with four known analogues (3, 6-8) and fifteen other compounds. Their structures were elucidated on the basis of comprehensive NMR, MS, and ECD spectroscopic data analysis. Among isolates, physapubescin J (1) contained an unusual sulphide linkage, and four withanolides (3, 5, 7 and 8) showed anti-inflammatory potential in LPS-induced RAW264.7 cells. This study supports P. pubescens fruit could be a valuable source of withanolides. Further studies to investigate anti-inflammatory activities of isolated withanolides using in vivo models are warranted.