Vinylphenylmercapturic acids in human urine as biomarkers of styrene ring oxidation

Biomarkers of toluene exposure in rats: mercapturic acids versus traditional indicators (urinary hippuric acid ando-cresol and blood toluene)

“…Thus, the rates for glutathione's reaction with the 2,3-oxide and 3,4-oxide appear to be the same for all monosubstituted aromatic compounds in rodents. Very recently, Linhart et al (Linhart et al, 2012) showed that vinylphenylmercapturic acids (VPMA) were present in the urine of hand-lamination workers exposed to styrene. In this case, p-VPMA was found to predominate to an extent suggesting a more pronounced regioselectivity for VPMA formation in humans.…”

Mercapturic acids: recent advances in their determination by liquid chromatography/mass spectrometry and their use in toxicant metabolism studies and in occupational and environmental exposure studies

“…The mercapturate products of 2,3-STO conjugation, 2- and 3-VPMA were detected only in trace amounts suggesting selective GSH conjugation at C4 of 3,4-STO over conjugation of 2,3-STO (Linhart et al, 2012). Formation of these mercapturates represents activity in a second toxicologically significant pathway of styrene activation and biotransformation (Linhart et al, 2012), Table 2). Although determination of these styrene mercapturates provides toxicologically relevant information, they are minor metabolites and do not reflect absorbed dose as accurately as the currently used biomarkers MDA and PGA (De Palma et al, 2001).…”

“…Alternatively 2,3- and 3,4-STO may react with GSH to initiate formation of three isomeric vinylphenolmercapturates (VPMAs). Of these mercapturates, 4-VPMA, the product of 3,4-STO conjugation, is the most abundant VPMA isomer (Linhart et al, 2010; Linhart et al, 2012). The mercapturate products of 2,3-STO conjugation, 2- and 3-VPMA were detected only in trace amounts suggesting selective GSH conjugation at C4 of 3,4-STO over conjugation of 2,3-STO (Linhart et al, 2012).…”

“…Of these mercapturates, 4-VPMA, the product of 3,4-STO conjugation, is the most abundant VPMA isomer (Linhart et al, 2010; Linhart et al, 2012). The mercapturate products of 2,3-STO conjugation, 2- and 3-VPMA were detected only in trace amounts suggesting selective GSH conjugation at C4 of 3,4-STO over conjugation of 2,3-STO (Linhart et al, 2012). Formation of these mercapturates represents activity in a second toxicologically significant pathway of styrene activation and biotransformation (Linhart et al, 2012), Table 2).…”