Negative ames tests of epoxide fatty methyl esters derived from homolysis of linoleic acid hydroperoxides

Five isomeric epoxyhydroxyene and epoxyoxoene fatty esters derived from homolytic decomposition of linoleic acid hydroperoxide were tested for mutagenicity by the ‘Ames’ top-agar incorporation method using S-9 mix derived from livers of male rats pretreated with Aroclor 1254. The epoxide fatty esters tested—methyl trans-12,13-epoxy- erythro-11-hydroxy- cis(trans)-9-octadecenoate and methyl trans-12,13-epoxy- threo-11-hydroxy- cis(trans)-9-octadecenoate (each composed of approximately 80% cis-9-ene and 20% trans-9-ene), methyl trans-12,13-epoxy-9-oxo- trans-10-octadecenoate, methyl trans-12,13-epoxy-9-hydroxy- trans-10-octadecenoate and methyl cis-12,13-epoxy-9-oxo- trans-10-octadecenoate—had structural characteristics similar to certain potent mutagens. However, these ester were not mutagenic in Salmonella typhimurium strains TA 100, TA98 or TA1537 at concentrations up to 2000 μg/test plate. Under the same test conditions, the methyl ester of hydroperoxy linoleic acid, from which these epoxides were derived, was weakly mutagenic in strain TA100 and possibly also in strain TA98.