Antimicrobial isoflavonoids from Erythrina crista galli infected with Phomopsis sp.

The isoflavonoids coumestrol, genistein and daidzein have been isolated and identified by bioassay-guided fractionation from the acetone extract of Erythrina crista galli young twigs infected with Phomopsis sp. These compounds showed antimicrobial activity against Bacillus brevis (MIC values 16.3, 64.8 and 137.8 microM, respectively). This is the first time that coumestrol, besides lutein and n-nonacosane, are reported in this species.