C-methylated and C-prenylated isoflavonoids from Root Extract of Desmodium Uncinatum

Abstract

A pterocarpan, 1,9-dihydroxy-3-methoxy-2-methylpterocarpan (named uncinacarpan) and two isoflavanones, 5,7-dihydroxy-20,30,40- trimethoxy-6-(3-methylbut-2-enyl)isoflavanone (named uncinanone D) and 5,40-dihydroxy-7,20-dimethoxy-6-methylisoflavanone (named uncinanone E), were isolated from the CH2Cl2 root extract of Desmodium uncinatum (Jacq.) DC and characterised by spectroscopic methods. In addition, a rare pterocarpan edudiol and two known abietane diterpenes, 7-oxo-15-hydroxydehydroabietic acid and 7- hydroxycallitrisic acid were identified. The fraction of the root extract that was analysed induced germination of Striga hermonthica seeds, but none of the isolated compounds showed this activity.