[A new lignanolide from the leaves of Daphne genkwa]

A new (-)-4-oxo-2,6-bis-(3',4'-methylenedioxy phenyl)-3, 7-dioxabicyclo[3, 3, 0] octane lignan, genkdaphin was isolated from the leaves of Daphne genkwa Sieb. et Zucc. mp 118-119.5 degrees C, C20H16O7 (HRMS, 368.08631, M+), [alpha]27D-64.8 degrees (c 0.5, CHCl3). On the basis of UV, IR, MS, 1H and 13CNMR spectral analysis, the structure of the genkdaphin has been established as (-)-4-oxosesamin.