A reassessment of the nomenclature of polychlorinated biphenyl (PCB) metabolites.

Abstract

Polychlorinated biphenyls (PCBs) are a widespread class of persistent organic chemicals that accumulate in the environment and humans and are associated with a broad spectrum of health effects. PCB biotransformation has been shown to lead to two classes of PCB metabolites that are present as contaminant residues in the tissues of selected biota: hydroxylated (HO) and methyl sulfone (MeSO2) PCBs. Although these two types of metabolites are related structures, different rules for abbreviation of both classes have emerged. It is important that a standardized nomenclature for the notation of PCB metabolites be universally agreed upon. We suggest that the full chemical name of the PCB metabolite and a shorthand notation should be adopted using the International Union of Pure and Applied Chemistry's chemical name/original Ballschmiter and Zell number of the parent congener, followed by the assignment of the phenyl ring position number of the MeSO2- or HO-substituent. This nomenclature provides a clear, unequivocal set of rules in naming and abbreviating the PCB metabolite structure. Furthermore, this unified PCB metabolite nomenclature approach can be extended to the naming and abbreviation of potential metabolites of structurally analogous contaminants such as HO-polybrominated biphenyls and HO-polybrominated diphenyl ethers.

Hydroxylated and methoxylated polybrominated diphenyl ethers in mollusks from Chinese coastal areas

“…Naturally occurring OH-and MeO-PBDEs have a similarity in structure that they all have a methoxyl or hydroxyl group in the ortho position relative to the ether bond (Maervoet et al, 2004), such as 6-MeO-BDE-47, 2 0 -MeO-BDE-68, 6-OH-BDE-47 and 2 0 -OH-BDE-68 which were the dominant OH-and MeO-PBDE congeners in mollusks. The current thinking is that OH-and MeO-PBDEs found in mollusks are mostly a consequence of accumulation via natural sources in marine environments.…”

Chlorinated hydrocarbon contaminants and metabolites in polar bears (Ursus maritimus) from Alaska, Canada, East Greenland, and Svalbard: 1996−2002

“…Methylsulfone metabolites were also determined, i.e., 3-MeSO 2 -p,pV-DDE and 20 MeSO 2 -PCB congeners (AMeSO 2 -PCB: 3-/4-MeSO 2 -CB-52, 3V-/4V-MeSO 2 -CB-49, 3-/4-MeSO 2 -CB-64, 3-/4-MeSO 2 -CB-70, 3V-/4V-MeSO 2 -CB-101, 3V-/4V-MeSO 2 -CB-87 (note: 3V-MeSO 2 -CB-87 may include traces of 5-MeSO 2 -CB-110 as they co-elute on a DB 5 column), 4-MeSO 2 -CB-110, 3-/4-MeSO 2 -CB-149, 3V-/4V-MeSO 2 -CB-132, 3V-/4V-MeSO 2 -CB-141, 4V-MeSO 2 -CB-174). The nomenclature of MeSO 2 -PCBs has been abbreviated and simplified based on the systematic numbering technique applied to PCB congeners (Guitart et al, 1993;Maervoet et al, 2004).…”

Determination of Hydroxylated Polychlorinated Biphenyls (HO-PCBs)in Blood Plasma by High-Performance Liquid Chromatography-Electrospray Ionization-Tandem Quadrupole Mass Spectrometry

“…The names of individual HO-PCB congeners are based on an abbreviation approach (17), which is based on the IUPAC numbering system for PCBs (chlorination pattern). HPLC-grade methanol and methyl-tert-butyl ether (MtBE) were obtained from Merck (Darmstadt, Germany).…”