title: In Vitro Transformation of Chlorinated Parabens by the Liver S9 Fraction: Kinetics, Metabolite Identification, and Aryl Hydrocarbon Receptor Agonist Activity.
abstract: We investigated the kinetics of in vitro transformation of a dichlorinated propyl paraben (2-propyl 3,5-dichloro-4-hydroxybenzoate; Cl2PP) by the rat liver S9 fraction and assessed the aryl hydrocarbon receptor (AhR) agonist activity of the metabolite products identified in HPLC and GC/MS analysis and by metabolite syntheses. The results indicated that the chlorination of Cl2PP reduced its degradation rate by approximately 40-fold. Two hydroxylated metabolite products showed AhR agonist activity of up to 39% of that of the parent Cl2PP when assessed in a yeast (YCM3) reporter gene assay. The determination of the metabolic properties of paraben bioaccumulation presented here provides further information on the value of risk assessments of chlorinated parabens as a means to ensure human health and environmental safety.
authors.affiliation: Department of Environmental Sciences, Faculty of Humanities and Social Sciences, Iwate University.
authors.forename: Masanori
authors.initials: M
authors.lastname: Terasaki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Wada
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nagashima
authors.forename: Masakazu
authors.initials: M
authors.lastname: Makino
authors.forename: Hiro
authors.initials: H
authors.lastname: Yasukawa
mesh_terms: D000818:Animals; D007700:Kinetics; D008862:Microsomes, Liver / Q000737:chemistry / Q000378:metabolism*; D015394:Molecular Structure; D010226:Parabens / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D018336:Receptors, Aryl Hydrocarbon / Q000819:agonists*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism
chemical_list: D010226:Parabens; D018336:Receptors, Aryl Hydrocarbon