Analytical Sciences

Abstract − Analytical Sciences, 20(1), 3 (2004).

Degradation of Estrogen Conjugates Using Titanium Dioxide as a Photocatalyst
Kuniko MITAMURA,  Hitomi NARUKAWA, Tatsuhito MIZUGUCHI, and Kazutake SHIMADA
Faculty of Pharmaceutical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-0934, Japan
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.