From the root bark of Ormosia monosperma, 10 isoflavonoids including t
wo new compounds '',3'':5,6)-8-(3-methyl-1,3-butadienyl)isoflavone, na
med ormosidin, and dalbergion 4'-O-beta-D-glucopyranoside, were isolat
ed. These structures were confirmed by spectroscopic analysis. 2,3-Dih
ydroauriculatin, one of the compounds isolated, showed moderate activi
ties against oral-microbial organisms (Streptococcus mutans, Prophyrom
onas gingivalis and Actinomyces actinomycetemcomitans).