title: In Vivo and in Vitro Isomer-Specific Biotransformation of Perfluorooctane Sulfonamide in Common Carp (Cyprinus carpio).
abstract: Biotransformation of PFOS-precursors (PreFOS) may contribute significantly to the level of perfluorooctanesulfonate (PFOS) in the environment. Perfluorooctane sulfonamide (PFOSA) is one of the major intermediates of higher molecular weight PreFOS. Its further degradation to PFOS could be isomer specific and thereby explain unexpected high percentages of branched (Br-) PFOS isomers observed in wildlife. In this study, isomeric degradation of PFOSA was concomitantly investigated by in vivo and in vitro tests using common carp as an animal model. In the in vivo tests branched isomers of PFOSA and PFOS were eliminated faster than the corresponding linear (n-) isomers, leading to enrichment of n-PFOSA in the fish. In contrast, Br-PFOS was enriched in the fish, suggesting that Br-PFOSA isomers were preferentially metabolized to Br-PFOS over n-PFOSA. This was confirmed by the in vitro test. The exception was 1m-PFOSA, which could be the most difficult to be metabolized due to its α-branched structure, resulting in the deficiency of 1m-PFOS in the fish. The in vitro tests indicated that the metabolism mainly took place in the fish liver instead of its kidney, and it was mainly a Phase I reaction. The results may help to explain the special PFOS isomer profile observed in wildlife.
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University , Tianjin 300071, P. R. China.
authors.forename: Meng
authors.initials: M
authors.lastname: Chen
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University , Tianjin 300071, P. R. China.
authors.forename: Liwen
authors.initials: L
authors.lastname: Qiang
authors.affiliation: College of Marine Science of Engineering, Tianjin University of Science and Technology , Tianjin 300457, P. R. China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Pan
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University , Tianjin 300071, P. R. China.
authors.forename: Shuhong
authors.initials: S
authors.lastname: Fang
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University , Tianjin 300071, P. R. China.
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Han
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University , Tianjin 300071, P. R. China.
authors.forename: Lingyan
authors.initials: L
authors.lastname: Zhu
mesh_terms: D017738:Alkanesulfonic Acids / Q000737:chemistry / Q000493:pharmacokinetics; D000818:Animals; D001711:Biotransformation; D002347:Carps / Q000378:metabolism*; D004781:Environmental Exposure; D005466:Fluorocarbons / Q000737:chemistry / Q000493:pharmacokinetics*; D066298:In Vitro Techniques; D008658:Inactivation, Metabolic; D007536:Isomerism; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D013449:Sulfonamides / Q000737:chemistry / Q000493:pharmacokinetics*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000493:pharmacokinetics*
chemical_list: D017738:Alkanesulfonic Acids; D005466:Fluorocarbons; D013449:Sulfonamides; D014874:Water Pollutants, Chemical; C063900:perfluorooctanesulfonamide; C076994:perfluorooctane sulfonic acid