New Flavones from Pongamia pinnata (L.) Merr

Abstract

From the root bark of Pongamia pinnata (L.) Merr. (P. glabra Vent.) five flavones have been isolated. The two major constituents are shown to be karanjin and a new furanoflavone named pongapin. By degradation and synthesis the structure of the latter is established as 7,8-furano-3-methoxy-3?,4?-methylenedioxyflavone. Of the three minor products, two appear to be isomeric with karanjin and pongapin respectively.