title: Degradation of estrogen conjugates using titanium dioxide as a photocatalyst.
abstract: Estrogen conjugates (estradiol-3-glucuronide, -17-glucuronide, estrone-glucuronide and -sulfate) were subjected to photodegradation using titanium dioxide immobilized on glass beads as a catalyst. Their time courses were measured by HPLC and compared with those of the unconjugated estrogens. Estradiol, its 17-glucuronide and estrone, which have an unconjugated phenolic hydroxy group at the C-3 position, were almost completely degraded by UV irradiation within 4 h. On the other hand, significant amounts of estradiol- and estrone-3-glucuronide (ca. 20%, 25%) and estrone sulfate (ca. 90%), which were conjugated at the 3-hydroxy group, remained after a 6.5 h irradiation. These results supported the hypothesis that the photodegradation of estrogens was initiated at the phenolic hydroxy group.
authors.affiliation: Faculty of Pharmaceutical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-0934, Japan. mitamura@p.kanazawa-u.ac.jp
authors.forename: Kuniko
authors.initials: K
authors.lastname: Mitamura
authors.forename: Hitomi
authors.initials: H
authors.lastname: Narukawa
authors.forename: Tatsuhito
authors.initials: T
authors.lastname: Mizuguchi
authors.forename: Kazutake
authors.initials: K
authors.lastname: Shimada
mesh_terms: D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D004967:Estrogens / Q000737:chemistry*; D010777:Photochemistry; D014025:Titanium / Q000737:chemistry*
chemical_list: D004967:Estrogens; C009495:titanium dioxide; D014025:Titanium