Phenolic Constituents in Erythrina x bidwilli and Their Activity against Oral Microbial Organisms

Abstract

Five flavonoid compounds, including two new isoflavanones, were isolated from the root bark of Erythrina x bidwilli. Their structures were determined to be 2,10-di(y,y-dimethylallyl)-3,9-dihydroxypterocarpan (erythrabyssin II), 6,8-di(y,y-dimethyIallyI)-7,2 'x2018;,4’-trihydroxyisoflavanone (bidwillon A), 8-y,y-dimethylallyl-2',4'-dihydroxy-[6',6'-dimethylpyrano-(2',3': 7,6)]isoflavanone (bidwillon B), 8-y,y-dimethyIalIyl-7,4 'x2018;-dihydroxyisoflavone (8-y,y-dimethyl-allyldaidzein), and 8-y,y-dimethylaIlyl-5,2',4'-trihydroxy-[6',6'-dimethylpyrano-(2',3'': 7,6)]isoflavone (auriculatin), by means of spectroscopic analysis. Some potent activities against oral microbial organisms (Fusobacterium nucleatum and Prevotella intermedia) were shown in these flavonoid compounds. © 1992, The Pharmaceutical Society of Japan. All rights reserved.