Two novel 5,5-spiroketal sesquiterpenoid isomers from the roots of

Two novel 5,5-spiroketal sesquiterpenoid isomers, duhuosesquid A (1) and duhuosesquid B (2) were isolated from the roots of Angelica biserrata (R. H. Shan & Yuan) C. Q. Yuan & R. H. Shan. Their structures were determined by extensive spectroscopic analyses, and the absolute configurations of 1 and 2 were assigned via NMR calculations and ECD calculations. Additionally, their anti-inflammatory activities were evaluated through in vitro assays, with IC50 values of 15.9 ± 1.2 μM and 14.2 ± 0.5 μM, respectively.