The major biliary metabolite of 2-amino-3-methylimidazo-[4, 5-f)quinoline (IQ) in the rat was identified as the sulfamate derivative, N-(3-methylimidazo[4, 5-f]quinolin-2-yl] sulfamic acid. Identification was accomplished primarily by u.v., 1H-n.m.r. and mass spectrometry of the material isolated from bile and confirmed by comparison with material synthesized by reaction of chlorosulfonic add with IQ. The sulfamate was shown to be non-mutagenic in bacterial forward mutation assays. Greater than 20% of an administered dose of IQ could be recovered from feces (17%) and urine (5%) as the sulfamate. Very little unmetabolized IQ was recovered in bile, urine, or feces. Thus, the unusual process of N-sulfation is a major contributor to the detoxification and elimination of IQ in the rat.
Bibliographical noteFunding Information:
This investigation was supported by Grant No. PO1-ES0O597 from the National Institute of Environmental Health Sciences, N.I.H. Grant No. RR-00317 which supports the mass spectrometry facility under the direction of Professor Klaus Biemann at Massachusetts Institute of Technology, and N.I.H. Grant No. RR-00995 which supports the NMR Facility of the Francis Bitter National Magnet Laboratory at Massachusetts Institute of Technology. We thank the Cancer Research Campaign for their support and contributions (B.C. and B.K.).