Mutagenicity of the human carcinogen treosulphan, and its hydrolysis product, dl-1,2:3,4-diepoxybutane in mammalian cells.

The cytotoxicity and mutagenicity of the human carcinogen, treosulphan, and its hydrolysis product, dl-1,2:3,4-diepoxybutane (DEB), were studied in Chinese hamster ovary, AS52, cells. Treosulphan (0.1-1.0 mM) is toxic and mutagenic at the gpt locus. A strong pH dependence was noted. DEB is cytotoxic and mutagenic at a much lower dose (0.025 mM), but these effects were not affected by pH. The results suggest that the toxic and mutagenic effects of treosulphan are mediated by its hydrolysis product DEB, and that the conversion of treosulphan to DEB is highly pH-dependent.