Withanolides from the stems and leaves of Physalis pubescens and their cytotoxic activity

Abstract

A phytochemical study of Physalis pubescens L. afforded twelve compounds, including six new withanolides (1, 4, and 6i–9), four new withanolide glucosides (2, 3, 5, and 6), and two known withanolides (10 and 11). Their structures were established via extensive spectroscopic analysis. The absolute configuration of 3 was assigned using X-ray crystallography, and the absolute configurations of the 1,2-diol moiety in 1 were determined using the in situ dimolybdenum electronic circular dichroism method. Compounds 7, 9, and 10 exhibited significant cytotoxicity against human prostate cancer cells (C4-2B and 22Rvl), human renal carcinoma cells (786-O, A-498, Caki-2, and ACHN), human melanoma cells (A375 and A375-S2), and human normal hepatic cell line (L02) with IC50 values in the range of 0.17–5.30μM.