Objective To investigate the withanolides from the aerial parts of Physalis minima and evaluate their in vitro anti-tumor activities against human colon cancer (HCT-116), triple-negative breast cancer (MDA-MB-231), and human erythroleukemia (HEL) cell lines. Methods The chemical constituents were isolated and purified using various chromatographic techniques. Their structures were elucidated through a comprehensive analysis of spectroscopic data, including infrared (IR), high-resolution mass spectrometry (HRMS), nuclear magnetic resonance (NMR), and electronic circular dichroism (ECD). The proliferation inhibitory activitiesof the isolated compounds against the above three cancer cell lines were evaluated using the MTT assay. Results Eight withanolides were isolated and identified from the aerial parts of P. minima, including two new compounds (1 and 2), which were characterized as (8R,9S,10R,13R,14R,16S,17R,20S,22R,24S)-14α,17α:16α,24α-diepoxy-13α,14β,22α-trihydroxy-1,15-dione-13,14-seco-ergosta-2,5-diene- 18,20-olide (1) and (8R,9S,10R,13R,14R,16S,17R,20S,22R,24R,25R)-14α,17α:14,27-diepoxy-13α,22α-dihydroxy-1,15-dione-13,14-seco-ergosta-2,5-diene-18,20-olide-24-propionic acid (2). The known compounds were identified as 5α-ethoxy-6β-hydroxy-5,6-dihydrophysalin B (3), physalin VI (4), physaminin F (5), physagulide D (6), pubesenolide (7), and physaminilide I (8). The in vitro bioassay results demonstrated that three compounds (1, 3, and 5) exhibited potent inhibitory activities against HCT-116 cells, with IC₅₀ values ranging from (10.97 ±1.62) to (39.20 ±2.17) μmol/L. Compound 3 displayed an IC₅₀ value of (19.36 ±1.03) μmol/L against MDA-MB-231 cells. Additionally, three compounds (1, 3, and 4) showed inhibitory effects on HEL cells, with IC₅₀ values ranging from (8.27 ±0.37) to (38.97 ±1.77) μmol/L. Conclusion Compounds 1 and 2 are new compounds. Compound 1 represents the first reported 22, 26-seco-nor-physalin, named phyminate A , while compound 2 is the first 22,26-seco-physalin featuring a 24-propionic acid moiety and a C-14/C-27 ether bridge, named phyminate B. The inhibitory activities of compounds 1, 3—5 against three tumor cell lines indicate their potential as anti-cancer candidates, justifying in-depth study.

Physalis minima L.  /  withanolides  /  anti-tumor activity  /  phyminate A  /  phyminate B  /  5α-ethoxy-6β-hydroxy-5,6-dihydrophysalin B