Physanolide A, a Novel Skeleton Steroid, and Other Cytotoxic Principles from <i>Physalis </i><i>a</i><i>ngulata</i>

Abstract

A novel withasteroid, physanolide A (1), with an unprecedented skeleton containing a seven-membered ring, and two new physalins, physalins U (2) and V (3), were isolated from Physalis angulata. The structures were elucidated from spectroscopic analysis, and plausible biosynthetic pathways were postulated. Physalins B (4), D (5), and F (6) showed strong cytotoxicity against multiple tumor cell lines, including KB, A431, HCT-8, PC-3, and ZR751, with EC50 values less than 4 μg/mL.