Pcb 117

PCB 136, 2,2′,3,3′,6,6′-hexachlorobiphenyl-4-ol (4-136), 2,2′,3,3′,6,6′-hexachlorobiphenyl-5-ol (5-136), 4,5-dimethoxy-2,2′,3,3′,6,6′-hexachlorobiphenyl (methylated derivative of 2,2′,3,3′,6,6′-hexachlorobiphenyl-4,5-diol; 4,5-136) and 2,2′,3′,4,6,6′-hexachloro-3-methoxybiphenyl (methylated derivative of 2,2′,3′,4,6,6′-hexachlorobiphenyl-3-ol; 3-150) were synthesized as described previously (Waller et al. 1999 (link)). The chemical structures and the abbreviations of the HO-PCB metabolites are shown in Figure 1A. Surrogate recovery standards (2,3,4′,5,6-pentachlorobiphenyl, PCB 117; 2′,3,3′,4,5,5′-hexachlorobiphenyl-4-ol, 4-159) and internal standard (2,2′,3,4,4′,5,6,6′-octachlorobiphenyl, PCB 204) were purchased from Accustandard (New Haven, CT). NAC and tetrabutylammonium sulfite were purchased from Fisher Scientific (Pittsburg, PA, USA). L-Glutathione and β-nicotinamide adenine dinucleotide 2′-phosphate reduced tetrasodium salt hydrate (NADPH) were obtained from Sigma-Aldrich (St. Louis, MO, USA). Pesticide grade n-hexane, 2-propanol and methyl tert-butyl ether (MTBE) were purchased from Fisher Scientific (Pittsburg, PA, USA).

Dimethyl sulfoxide (DMSO), sodium phosphate dibasic (Na₂HPO₄), sodium phosphate monobasic (NaH₂PO₄), magnesium chloride (MgCl₂), tetrabutylammonium sulfite, sodium sulfite and pesticide grade solvents were obtained from Fisher Scientific (Pittsburg, PA, USA). Nicotinamide adenine dinucleotide phosphate reduced (NADPH) was purchased from Sigma-Aldrich Co. (St. Louis, MO, USA). Racemic PCB 136 was synthesized by the Ullmann coupling of 2,3,6-trichloro-1-iodobenzene²⁸ and the atropisomers of PCB 136 were separated using two serially connected Nucleodex β-PM columns (Macherey-Nagel, Düren, Germany). The enantiomeric fractions (EF = Area_{(+)-PCB 136} /(Area_{(+)-PCB 136} + Area_{(−)-PCB 136})) of (−)-PCB 136 and (+)-PCB 136 were 0.01 and 1.00, respectively.^{27 (link)} 2,2′,3,3′,6,6′-Hexachlorobiphenyl-4-ol (4-136), 2,2′,3,3′,6,6′-hexachlorobiphenyl-5-ol (5-136), 4,5-dimethoxy-2,2′,3,3′,6,6′-hexachlorobiphenyl and 2,2′,3′,4,6,6′-hexachloro-3-methoxybiphenyl were prepared as described elsewhere.^{29 (link)} Recovery standards (2,3,4,4′,5,6-hexachlorobiphenyl, PCB 166; 2,3,4′,5,6-pentachlorobiphenyl, PCB 117; 2,3,3′,4,5,5′-hexachlorobiphenyl-4-ol, 4′-159) and internal standard (2,2′,3,4,4′,5,6,6′-octachlorobiphenyl, PCB 204) were purchased from Accustandard (New Haven, CT).