A new lignan rhamnoside from Bauhinia retusa seed pods (Caesalpiniaceae)

A new lignan rhamnoside identified as 2,6-di(4′,5′-dihydroxyphenyl)-3,7-dioxabicyclo[3.3.0]octane-1-hydroxy-5- O -rhamnopyranoside ( 1 ) has been isolated from the ethanolic extract of seed pods of Bauhinia retusa . Its structure was established by extensive spectroscopic techniques (UV, IR, 1D NMR, 2D NMR, HRESIMS).