The mutagenicity of natural products from marine algae.

5 polyhalogenated hydrocarbon natural products isolated from the marine red alga Plocamium spp. were tested for mutagenicity in the Ames reversion assay. All 5 of the compounds induced revertants in Salmonella typhimurium strains TA100 and TA1535, indicating the mutational events involved base substitutions. One of the compounds, designated cross-conjugated ketone, was shown to be almost 200 times more effective as a mutagen than was ethyl methanesulfonate.