New isoflavonoids from Erythrina arborescens and structure revision of anagyroidisoflavone A

Five hitherto unknown isoflavonoids, namely erythrinins D-H (1–5), were isolated from the ethanol extract of Erythrina arborescens. Their structures were elucidated on the basis of extensive spectroscopic studies. In addition, the structure of anagyroidisoflavone A (6a) has been revised as 1″-O-methylerythrinin F (6) by re-analysis of the original spectroscopic data.