Tyrosinase-catalyzed oxidation of 17beta-estradiol: structure elucidation of the products formed beyond catechol estrogen quinones.
This paper reports a systematic characterization of the products formed by oxidation of 17beta-estradiol (1) with tyrosinase/O2 at low concentrations of physiological relevance. With the substrate at 1-10 nM concentration, the main reaction products included, beside the catechol estrogens 2-hydroxyestradiol (2) and 4-hydroxyestradiol (3), 6-oxo-2-hydroxyestradiol (4), 9,11-dehydro-2-hydroxyestradiol (6), 6,7-dehydro-2-hydroxyestradiol (7), and 9,11-dehydro-4-hydroxyestradiol (10). At higher estradiol concentrations, e.g., 1 microM, 6,7,8,9-dehydro-2-hydroxyestradiol (5) and the dimeric products 8 and 9 were also formed. The origin of these products from oxidative routes of 2 and 3 was established. Overall, the results of this study disclose novel aspects of the reactivity of 1 with the tyrosinase/O2 system and provide the first inventory of the oxidation products of catechol estrogen quinones.
Pezzella
Alessandro
A
Department of Organic Chemistry and Biochemistry, University of Naples Federico II Complesso Universitario Monte S. Angelo, Via Cinthia 4, I-80126, Naples, Italy. alesssandro.pezzella@unina.it
Lista
Liliana
L
Napolitano
Alessandra
A
d'Ischia
Marco
M
D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D004958:Estradiol / Q000737:chemistry* / Q000378:metabolism*; D002393:Estrogens, Catechol / Q000737:chemistry* / Q000378:metabolism*; D015394:Molecular Structure; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D010084:Oxidation-Reduction; D011809:Quinones / Q000737:chemistry* / Q000378:metabolism*
D002393:Estrogens, Catechol; D011809:Quinones; D004958:Estradiol; D014442:Monophenol Monooxygenase