A new eremophilane glycoside from the fruits of Physalis pubescens and its cytotoxic activity
Physalis pubescens L. has been used as a traditional folk medicine in China. Comprehensive studies aimed at identifying the bioactive constituents are still lacking. In the course of searching bioactive secondary metabolites from P. pubescens L., phytochemical investigation of the fruits of P. pubescens L. led to the isolation of one new eremophilane glycoside, 1β,3α-dihydroxy-7α-eremophila-911-dien-3-O-[α-L-arabinopyranosyl-(l→6)]-β-D-glucopyranoside (1), and six known glycosides (2–7). Their structures were established via extensive spectroscopic data including 1D and 2D NMR and HRESIMS. Cytotoxic effects against six human cancer cell lines (C4-2B, A375, A375-S2, 786-O, Caki-2, and ACHN) and one human normal hepatic cell line (L02) were evaluated and compounds 1 and 2 exhibited moderate cytotoxicity against C4-2B and A375 cell lines with IC50 values in the range of 6.78–28.3 μM. The study indicates that the fruits of P. pubescens L. have the potential to be used for drug discovery.