A new ellagitannin, methyl (S)-flavogallonate (14) along with fourteen known compounds, gallic acid, methyl gallate, ethyl gallate, 2,3-di-O-[( S)-4,5,6,4',5',6'-hexahydroxybiphenyl-2,2'-diyldicarbonyl]-(alpha/beta)-D-glucopyranose (4), vitexin, isovitexin, orientin, iso-orientin, kaempferol 3-O-beta-D-rutinoside, rutin, neosaponarin, ellagic acid, flavogallonic acid (13), and (alpha/beta)-punicalagin (15) have been isolated from the leaves of Terminalia myriocarpa Heurck. Protective effect of the major and structurally related compounds 4, 13, 15 and the new compound 14 against CCl 4 -induced hepatotoxicity has been evaluated and compared, using adult male rats weighing 200-250 g. Serum levels of glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), lipid peroxide and nitric oxide production were significantly increased by administration of CCl 4 to rats and then reduced significantly only by treatment with compounds 4, 14 and 15 in a dose-dependent manner. Comparison of the protective properties of these compounds showed that compound 14 is more potent than compound 15 than 4 and that compound 13 has a non-significant effect at the used two dose levels.