Induced Isoflavonoids from Fungus-Infected Stems of Pigeon Pea ( Cajanus cajan)

Abstract

Abstract Four antifungal isoflavones [7-hydroxy-4′-methoxy-(l) ; 5,7,4′-trihydroxy-(2) ; 5,7,2′,4′-tetra-hydroxy-(3) ; 5,2′,4′-trihydroxy-7-methoxy-(4) ] and one isoflavanone [ (5,2′-dihydroxy-7,4′-dimeth-oxy-(7)] have been isolated from the fungus-infected stems of Cajanus cajan . A sixth compound has been provisionally identified as 5,2′-dihydroxy-7,4′-dimethoxyisoflavone (5). The structure of 5,2′-dihydroxy-7,4′-dimethoxyisoflavanone (cajanol) was confirmed by synthesis from ferreirin ( 5,7,2′-trihydroxy 4′-methoxyisoflavanone).