Three new 2,4′-epoxy-8,5′/8,3′-neolignans from Penthorum chinense.

Graphical abstract Highlights • Phytochemical study on Penthorum chinense yielded 3 new 2,4′-epoxy-8,5′/8,3′-neolignans. • 2,4′-Epoxy-8,3′-neolignan glycosides are reported for the first time. • 2,4′-Epoxy-8,5′/8,3′-neolignans were only found in P. chinense. Abstract Three new neolignans (1 − 3), including one 2,4′-epoxy-8,5′-neolignan and two 2,4′-epoxy-8,3′-neolignan glycosides, were isolated from the EtOAc-soluble portion of the water decoction of Penthorum chinense Pursh. Their structures and absolute configurations were elucidated by comprehensive analysis of spectroscopic data and electronic circular dichroism (ECD) calculations. Notably, the unusual 2,4′-epoxy-8,3′-neolignan glycosides are reported for the first time. [ABSTRACT FROM AUTHOR]