Unusual isomeric corniculatolides from mangrove, Aegiceras corniculatum

Four new isomeric macrolides of combretastatin D-2 congeners named isocorniculatolide A (1), 11-O-methylisocorniculatolide A (2), 11-O-methylcorniculatolide A (3), and 12-hydroxy-11-O-methylcorniculatolide A (4), and the known corniculatolide A (5), arjunolic acid, and maslinic acid were isolated from the CHCl(3) extract of the bark of Aegiceras corniculatum. The structures of the new compounds (1-4) were elucidated by a combination of spectroscopic analysis (1-5), chemical modifications, and single-crystal X-ray analysis (1).