Indicanines B and C, two isoflavonoid derivatives from the root bark of Erythrina indica

In addition to two known compounds, 5,4'-di-O-methylalpinumisoflavone and c ajanin, a new 3-phenylcoumarin metabolite, named indicanine B, and a new is oflavone derivative, named indicanine C, were isolated from the root bark o f Erythrina indica. By means of spectroscopic analysis, the structures of t he new compounds were characterized as 4-hydroxy-3-(4'-hydroxyphenyl)5-meth oxy-2 ",2 "-dimethylpyrano [5 ",6 ":6.7] coumarin and 4'-hydroxy-5-methoxy- 2",2"-dimethylpyrano [5 ",6 ":6,7] isoflavone, respectively. The C-13-NMR d ata of cajanin and the in vitro antimicrobial spectrum and potencies of the isolated compounds ale also reported. ((C) 2000 Elsevier Science Ltd. All rights reserved.