title: Tracing the Biotransformation of PCBs and PBDEs in Common Carp (Cyprinus carpio) Using Compound-Specific and Enantiomer-Specific Stable Carbon Isotope Analysis.
abstract: Compound-specific and enantiomer-specific carbon isotope composition was investigated in terms of biotransformation of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) as well as atropisomers of chiral PCB congeners in fish by exposing common carp (Cyprinus carpio) to certain PCB and PBDE congeners. The calculated carbon isotope enrichment factors (εC) for PCB 8, 18, and 45 were -1.99, -1.84, and -1.70‰, respectively, providing evidence of the metabolism of these congeners in fish. The stable carbon isotopic compositions of PBDE congeners clearly reflect the debromination of PBDEs in carp. Significant isotopic fractionation was also observed during the debromination process of BDE 153 (εC= -0.86‰). Stereoselective elimination of chiral PCB congeners 45, 91, and 95 was observed, indicating a stereoselective biotransformation process. The similar εCvalues for E1-PCB 45 (-1.63‰) and E2-PCB 45 (-1.74‰) indicated that both atropisomers were metabolized by the same reaction mechanisms and stereoselection did not occur at carbon bond cleavage. However, the εCvalues of (+)-PCB 91 (-1.5‰) and (-)-PCB 95 (-0.77‰) were significantly different from those of (-)-PCB 91 and (+)-PCB 95, respectively. In the latter, no significant isotopic fractionations were observed, indicating that the stereoselective elimination of PCB 91 and 95 could be caused by a different reaction mechanism in the two atropisomers.
authors.affiliation: State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, P. R. China.|University of Chinese Academy of Sciences , Beijing 100049, P. R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, P. R. China.
authors.forename: Xiao-Jun
authors.identifier: 0000-0002-2572-8108
authors.initials: XJ
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, P. R. China.
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Zeng
authors.affiliation: State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, P. R. China.
authors.forename: Bi-Xian
authors.initials: BX
authors.lastname: Mai
mesh_terms: D000818:Animals; D001711:Biotransformation; D002244:Carbon; D002247:Carbon Isotopes; D002347:Carps / Q000378:metabolism; D055768:Halogenated Diphenyl Ethers / Q000378:metabolism*; D011075:Polybrominated Biphenyls / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D055768:Halogenated Diphenyl Ethers; D011075:Polybrominated Biphenyls; D002244:Carbon; D011078:Polychlorinated Biphenyls