supplementary material is available for this article at 10.1007/s13659 - 013 - 0062 - 3 and is accessible for authorized users .
five hitherto unknown isoflavonoids , namely erythrinins d - h ( 15 ) , 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 . 
 electronic supplementary materialsupplementary material is available for this article at 10.1007/s13659 - 013 - 0062 - 3 and is accessible for authorized users .