Withanolides from Physalin angulata and Their Inhibitory Effects on Nitric Oxide Production

Six new withanolides, angulasteroidins A?F ( 1 – 6 ), along with twelve known analogs ( 7-18 ) were isolated from the whole plants of Physalis angulata. Their structures were elucidated by analysis of 1D and 2D NMR, ECD and IR spectra, HR-ESI-MS data, and ECD calculation. Compounds 1 and 6 were rare 1–10 seco withanolides. Compounds 2 – 4 , 7 – 9 , and 15 exhibited significant inhibitory activity on the production of nitric oxide in the LPS-activated RAW 264.7 mouse macrophage cell lines with IC₅₀ values ranging from 0.23 to 9.06 μM.