Natural occurrence of 3-aryl-4-hydroxycoumarins. Part I. Phytochemical examination of Derris robusta(roxb.) benth.

Abstract

The root material of Derris robusta has yielded nine natural products whose structures have been determined mainly by physical methods in association with a few partial syntheses and degradations. Four of these have been shown to be new natural isoflavones: derrustone (II), derrubone (IIIa), robustone (VIa), and robustone methyl ether (VIb). The other five compounds are derivatives of the 3-aryl-4-hydroxycoumarin type, and include derrusnin (VIIb), robustic acid (IXa), robustic acid methyl ether (IXb), robustin (XIIa), and robustin methyl ether (XIIb). These 3-aryl-4-hydroxy(or methoxy)coumarins are variants upon the isoflavonoid theme. The pattern relating the structures of these co-occurring isoflavones and 3-aryl-4-oxycoumarins indicates that the biosyntheses of these two natural product types probably have many common features.