2005 Volume 51 Issue 4 Pages 447-452
Contribution of glucuronic acid and sulfonic acid moieties during the photocatalytic degradation of estrogen conjugates, one of the endocrine disrupting chemicals, has been investigated. Estrogens were subjected to photocatalytic degradation using titanium dioxide immobilized on glass beads as a catalyst, whose time courses were measured by HPLC or liquid chromatography (LC)/MS/(MS). Estradiol and estrone, which have an unconjugated phenolic hydroxy group at the C-3 position, were gradually degraded by UV irradiation and nearly disappeared within 6 hr. 3-Desoxyestradiol, which does not have a phenolic hydroxy group at C-3 position, was also degraded like estradiol. The corresponding 17- or 3-glucuronide was degraded faster than the respective genin, estradiol or estrone. The double conjugate, estriol 3-sulfate 16-glucuronide, was also easily degraded within 3 hr. On the other hand, the degradation of estrogen 3-sulfate did not start within 2.5 hr but the reaction was completed within 6 hr. These data showed that the glucuronic acid moiety on the estrogen skeleton and sulfonic acid moiety at phenolic hydroxy group play an important role for this degradation reaction.
