Abstract
Physalis Alkekengi L. var. franchetii (Mast.) Makino (PAF), which is used in both food and medicine, has a long history of about 1800 years of application in China. There are many active constituents in the calyx of PAF. Physalins and physalins with a single oxygen bridge are the unique components of the PAF calyx. Physalins with multiple biological activities, including anticancer activity, antimicrobial activity, anti-inflammatory activity, etc., have been found. As such, physalins deserve to be studied further. In this study, we aimed to extract, separate, and identify the effective components of physalins from the calyx of PAF and investigate ability to inhibit the proliferation of tumor cell lines. Three new physalins, physalin VIII (1), 3α-hydroxy-2,3,25,27-tetrahydro-4,7-didehydro-7-deoxyneophysalin A (2), and physalin IX (3), along with three known compounds, physalin L (4), physalin D (5), and alkekengilin A (6) were isolated from PAF calyxes. Physalin D was superior to the positive control drug cisplatin in inhibiting the proliferation of five tumor cell lines. The physalin compounds exhibited potential antitumor activity, being deemed worthy of further research in the fields of antitumor drug development and the application in health foods.