DESMUTAGENIC EFFECT OF PHEOPHYTIN FROM JA PANESE EGGPLANT AGAINST SEVERAL MUTAGENS

Using Salmonella typhimurium TA98 in the Ames test, we have identified desmutagens in Japanese eggplant juice. Most of the desmutagenic acti vity in the eggplant fruit is due to pheophytin, a Mg-free derivative of chlorophyll. Pheophytin inhibits mutagenesis to about 40% with or w ithout metabolic activation of mutagens by S9 mix preparations. The mu tagens employed were 2-aminoanthracene (2-AA), 2-aminofluorene (2-AF), 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeA alpha C), 3-amino-1-meth yl-5H-pyrido[4,3-b]indole (Trp-P-X) and 2-nitrofluorene (2-NF). Pheoph ytin did not influence enzymes involved in metabolic activation or int erfere with the activation process when S9 was added. Therefore pheoph ytin appears to be a desmutagen acting directly on the mutagens. Trp-P -2-pheophytin reaction products could not be isolated by HPLC or deter mined by H-1-NMR under various conditions owing to their instability. The desmutagenicity of pheophorbide, the phorbin skeleton of pheophyti n, against Trp-P-2 was approximately 40%, but phytol, the carbon chain of pheophorbide, showed no desmutagenicity. This suggests that the de smutagenicity of pheophytin is derived from the pyrole rings.