A new pair of butylphthalide diastereomers from the roots of Angelica sinensis

A new pair of butylphthalide diastereomers, dangguinolide A (1) and dangguinolide B (2), together with two known butylphthalide were isolated from Angelica sinensis. Their structures were determined by extensive spectroscopic analyses, and the absolute configurations of 1 and 2 were assigned via NMR calculations and ECD calculations. Their anti-inflammatory activities have evaluated in vitro.