Abstract
Chemical analyses of the stem bark of Erythrina sigmoidea (Fabaceae) yielded a new flavonoid, designated sigmoidin L (1), the known erythrinasinate, E-p-coumaric acid docosylester, and 3′-prenylnaringinin, reported here for the first time for the stem bark of E.sigmoidea. The structure of 1 was established by chemical and spectroscopic means as 5,7, 3′,4′-tetrahydroxy-5′-[3″-methyl-4″-oxobut-(1″Z) enyl]flavanone. Sigmoidin L exhibited significant antibacterial potency in vitro against Staphylococus aureus and Proteus vulgaris.