title: 6:2 Fluorotelomer iodide in vitro metabolism by rat liver microsomes: comparison with [1,2-(14)C] 6:2 fluorotelomer alcohol.
abstract: 6:2 Fluorotelomer iodide [6:2 FTI, F(CF2)6CH2CH2I] is the industrial raw material used to manufacture 6:2 fluorotelomer alcohol [6:2 FTOH, F(CF2)6CH2CH2OH] and 6:2 FTOH-based products. During its manufacture and industrial use, workers may be exposed to via oral, dermal or inhalation of 6:2 FTI. Therefore it is useful to understand how 6:2 FTI may be metabolized and into what transformation products. 6:2 FTI in vitro rat liver microsomal metabolism was explored for the first time to compare its biotransformation potential with that of [1,2-(14)C] 6:2 FTOH [F(CF2)6(14)CH2(14)CH2OH]. 6:2 FTI and 6:2 FTOH metabolite yields were determined in closed-bottle systems using Sprague Dawley and Wistar Han rat microsomes after incubation at 37 °C for up to 6h with NADPH (reduced form of nicotinamide adenine dinucleotide phosphate)-addition and NADPH-regenerating systems, respectively. 5:3 acid [F(CF2)5CH2CH2COOH] was the most abundant metabolite for 6:2 FTI (3.3-6.3 mol%) and 6:2 FTOH (9-12 mol%). Perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPeA), and perfluorohexanoic acid (PFHxA) in sum accounted for 1.3-2.2 mol% from 6:2 FTI and 2.7-4.4 mol% from 6:2 FTOH biotransformation. Perfluoroheptanoic acid (PFHpA) accounted for 0.14-0.36 mol% from 6:2 FTI but only 0.01-0.06 mol% from 6:2 FTOH biotransformation. These results suggest that mammalian systems exposed to 6:2 FTI or 6:2 FTOH would form 5:3 acid, PFBA, PFPeA, PFHxA as the primary stable metabolites, whereas more PFHpA would be expected from 6:2 FTI biotransformation.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Ruan
authors.affiliation: E.I. du Pont de Nemours & Company, Inc., Newark, DE, USA.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Sulecki
authors.affiliation: E.I. du Pont de Nemours & Company, Inc., Newark, DE, USA.
authors.forename: Barry W
authors.initials: BW
authors.lastname: Wolstenholme
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China. Electronic address: gbjiang@rcees.ac.cn.
authors.forename: Guibin
authors.initials: G
authors.lastname: Jiang
authors.affiliation: E.I. du Pont de Nemours & Company, Inc., Newark, DE, USA. Electronic address: ning.wang@dupont.com.
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.affiliation: E.I. du Pont de Nemours & Company, Inc., Newark, DE, USA.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Buck
mesh_terms: D000818:Animals; D058448:Biota; D001711:Biotransformation; D006845:Hydrocarbons, Fluorinated / Q000378:metabolism* / Q000633:toxicity; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D016273:Occupational Exposure / Q000009:adverse effects; D051381:Rats; D018570:Risk Assessment
chemical_list: D006845:Hydrocarbons, Fluorinated
keywords: 5:3 Acid; 6:2 Fluorotelomer alcohol (6:2 FTOH); 6:2 Fluorotelomer iodide (6:2 FTI); In vitro metabolism; Perfluorocarboxylic acids (PFCAs); Rat liver microsomes