FLAVONOIDS IN ROOT BARK OF PONGAMIA-PINNATA

Further investigation of the flavonoid constituents of Pongamia pinnata from Japan resulted in the isolation of 18 flavonoid compounds including nine new ones, ponganones III-XI, from its root bark. The new structures were determined to be (2S)-3',4'-dimethoxy-6'',6''-dimethylpyrano[2'',3'':7,8]-flavanone (III), (2S)-6,3',4'-trimethoxy-6'',6''-dimethylpyrano[2'',3'':7,8]-flavanone (IV), (2S)-7-methoxy-6-O-gamma,gamma-dimethylallyl-3',4'-methylene-dioxyflavanone (V), 2'-hydroxy-3,4,5'-trimethoxy-6'',6''-dimethylpyrano[2'',3'':4',3']chalcone (VI), 2',4'-dimethoxy-3,4-methylenedioxydioxydihydrochalcone (VII), 2',5',beta-trimethoxy-3,4-methylenedioxy-6'',6''-dimethylpyr-ano[2'',3'':4',3']dihydrochalcone (VIII), 2,beta-dimethoxy-3,4-methylenedioxy-furano[2'',3'':4',3']-dihydrochalcone (IX), beta-hydroxy-2',4',6'-trimethoxy-3,4-methylenedioxychalcone (X) and 3-methoxy-furano-[2'',3'':7,6]flavone (XI), respectively, by means of spectral analysis and synthesis.