[Studies on the chemical constituents of Flemingia philippinensis]

Two new prenylated flavonoids, flemiphilippinin C (I) and flemiphilippinin D (II) have been isolated from the root of Flemingia philippinensis (Merr. et Rolfe) Li along with four known compounds. The structure of I and II were elucidated as 7-(.4'-hydroxy-3'-methoxyphenyl)-5-hydroxy-2, 2-dimethyl-10-prenyl-2H,6H-benzo-[1,2-b:5,4-b']dipyran-6-one and 5,7,2',4'-tetrahydroxy-6,8-diprenylisoflavanone, respectively, on the basis of chemical and spectroscopic data. The four known compounds were identified as 5,7,3',4'-tetrahydroxy-6,8-diprenylsilflavone (III), flemichin D (IV), beta-sitosterol (VI) and lupeol (VII), and a mixture of n C22-C30 aliphatic acid (V). Compounds III and IV showed significant cytotoxic activities against P388 cell cultures.