The present study was undertaken to evaluate the role of individual Ñavanols in the antimutagenic potential of green tea. Aqueous extracts of green tea were fractionated into four fractions, each of which was fully deÐned with respect to its content of ([)-epigallocatechin gallate, ([)-epicatechin gallate, ([)-epigallocatechin, ([)-epicatechin and gallic acid. The ability of each fraction to antagonize the mutagenicity of four model mutagens, namely Nnitrosopyrrolidine, benzo(a)pyrene, 2-aminoanthracene and Glu-P-1 (2-amino-6methyldipyrido[1,2-a : 3,2-d]imidazole), was investigated in the Ames test. No correlation could be established between any of the Ñavanols and antimutagenic potential. Similarly, no correlation was evident between the Ñavanol content of each fraction and its ability to inhibit CYP1A, as exempliÐed by the Odealkylations of methoxy-and ethoxy-resoruÐn. Furthermore, no relationship could be established between CYP2B activity, as exempliÐed by the Odepentylation of pentoxyresoruÐn and the antimutagenic potential of green tea. Using a modiÐed Ames test procedure, the ability of each tea fraction to scavenge the metabolically generated reactive intermediates of the model mutagens was investigated, this being an additional mechanism of the antimutagenic potential of green tea. Generally, fractions with high Ñavanol content were more e †ective scavengers. It is concluded that the contribution of Ñavanols to the antimutagenic activity of green tea is, at best, limited.