Antihepatotoxic activity of phenolic flavan-3-ols and their derivatives.

The protective activity against carbon tetrachloride induced hepatotoxicity of several phenolic flavan-3-ols and their derivatives has been assessed. Our research showed that monomers possessing a pyrogallol moiety as the B-ring had greater activity and this was not directly related to the stereo-chemistry of the hydroxyl group at C-3 in the flavan unit. However, when a galloyl group was linked to the hydroxyl group to form a gallate, this product exhibited markedly more activity than other analogs. These results suggest that the antihepatotoxic activity of phenolic flavan-3-ols and their derivatives seem to be related to the galloylation at the C-3 hydroxyl group in the flavan skeleton rather than the structure of another moiety or the degree of condensation.