Chemical Studies on the Constituents of the Thymelaeaceous Plants. IV. Structure of a New Spiro Biflavonoid, Genkwanol A, from the Root of Daphne genkwa SIEB. et ZUCC.

Abstract

A new spiro biflavonoid, genkwanol A (4) was isolated from the root of Daphne genkwa SIEB. et ZUCC. (Thymelaeaceae), as well as daphnodorin B (2), umbelliferone, daphnoretin, daphnin, syringin and yuenkwanin. The structure of 4 was established by chemical transformation of 4 into 2 with dil. HCl in MeOH, and spectroscopic means (circular dichroism, mass and nuclear magnetic resonance).