title: A novel estrogenic compound transformed from fenthion under UV-A irradiation.
abstract: The photo-transformed products of fenthion well-known as one of the most photosensitive organophosphorus insecticides and their estrogenic activities were investigated using a yeast two-hybrid assay incorporating the human estrogen receptor alpha (hERalpha). We identified fenthion sulfoxide and 3-methyl-4-methylsulfinylphenol (MMS) as the major transformed products and 3-methyl-4-(methylthio)phenol (MMP) as the minor product under UV-A irradiation. Further, significant estrogenic activity was observed in the solution irradiated for 160 min; this activity was evaluated as 18 pM converted to 17beta-estradiol (E(2)) equivalent concentration. By using authentic standards, it was found that MMP possessed weak estrogenic activity; its activity was evaluated as 1.7x10(-6) times compared with that of E(2). However, it was also revealed that the activity due to MMP was only 13%. From high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR) spectroscopies, we newly identified a significant estrogenic compound transformed from fenthion, O,O-dimethyl S-[3-methyl-4-(methylthio)phenyl]phosphorothioate, S-aryl fenthion.
authors.affiliation: Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, 52-1, Yada, Suruga-ku, Shizuoka 422-8526, Japan. p7404@mail.u-shizuoka-ken.ac.jp
authors.forename: Kenta
authors.initials: K
authors.lastname: Yamada
authors.forename: Masanori
authors.initials: M
authors.lastname: Terasaki
authors.forename: Masakazu
authors.initials: M
authors.lastname: Makino
mesh_terms: D004958:Estradiol; D047628:Estrogen Receptor alpha / Q000378:metabolism; D004967:Estrogens / Q000737:chemistry*; D005284:Fenthion / Q000737:chemistry* / Q000528:radiation effects; D006801:Humans; D007306:Insecticides / Q000737:chemistry / Q000528:radiation effects; D009943:Organophosphorus Compounds / Q000737:chemistry / Q000528:radiation effects; D010636:Phenols; D013454:Sulfoxides; D020798:Two-Hybrid System Techniques; D014466:Ultraviolet Rays
chemical_list: D047628:Estrogen Receptor alpha; D004967:Estrogens; D007306:Insecticides; D009943:Organophosphorus Compounds; D010636:Phenols; D013454:Sulfoxides; D004958:Estradiol; D005284:Fenthion