7-Amino-2,4,6-trimethylquinoline as a mutagenic pyrolysate compound of polyurethane foam

Commercial polyurethane foam was pyrolyzed by gas burners at 600-700 degrees C for 2 h with introduction of air (200 ml/min). Gaseous pyrolysate was trapped in water and 10% hydrochloric acid. Basic and neutral pyrolysates have a mutagenic activity (447 revertants/10 micrograms) in Salmonella typhimurium TA98 in the presence of a mammalian metabolic activation system. These pyrolysates contained 12.32 mg of amino compounds as diaminotoluene per g polyurethane foam, amounts which are 120 times higher than those in unpyrolysed polyurethane foam. Basic and neutral pyrolysates were subjected to silica gel column chromatography, and 6 fractions having mutagenic potency were obtained. The colorless needles (m.p. 200.5-202 degrees C) were separated from fraction 4. These needles have the most potent mutagenicity (678 revertants/2 micrograms) in basic and neutral pyrolysates in Salmonella typhimurium TA98 with 10% S9 mix. From the physicochemical data, the structure of the compound was estimated to be an aminoquinoline derivative, and was identified using synthesized 7-amino-2,4,6-trimethylquinoline by mixed melting point, thin-layer co-chromatography and gas chromatography-mass spectrometry.