Estrogen catechol

Cavalieri, E. Chakravarti, D. Guttenplan, J. Hart, E. Ingle, J. Jankowiak, R. Muti, P Rogan, E. Russo, J. Santen, R. Sutter, T. Catechol estrogen quinones as initiators of breast and other human cancers implications for biomarkers of susceptibility and cancer prevention. Biochim. Biophys. Acta 2006, 1766, 63-78. 

Bolton, J. L. Shen, L. p-Quinone methides are the major decomposition products of catechol estrogen o-quinones. Carcinogenesis 1996, 17, 925-929. 

Stack, D. E. Byun, J. Gross, M. L. Rogan, E. G. Cavalieri, E. L. Molecular characteristics of catechol estrogen quinones in reactions with deoxyribonucleosides. Chem. Res. Toxicol. 1996, 9, 851-859. 

Mitamura K, Yatera M, Shimada K. 2000. Studies on neurosteroids. Part XIII. Characterization of catechol estrogens in rat brains using liquid chromatography-mass spectrometry-mass spectrometry. Analyst 125 811. 

Catechol estrogens, 157 Celacinnine, 590 Ceric pyridinium chloride, 184 Cerium amalgam, 114 Cerium(IV) ammonium nitrate. 184 Cerium(IV) ammonium nitrate-sodium hmmatc. 114... 

Catechol estrogens.2 Hydroboration-oxidation of the 2-chloromercuric derivative (2) of an estrogen (1) results in the catechol estrogen 3 in 45% overall yield. An alternate route to 3 is also shown in equation (I). 

Chen ZH, Hurh YJ, Na HK, Kim JH, Chun YJ, Kim DH, Kang KS, Cho MH, Surh Y-J. 2004. Resveratrol inhibits TCDD-induced expression of CYP1A1 and CYP1B1 and catechol estrogen-mediated oxidative DNA damage in cultured human mammary epithelial cells. Carcinogenesis 25 2005-2013. 

COMT methylates quercetin to form isorhamnetin and tamarixetin, but quercetin can inhibit COMT methylation of catechol estrogens in human liver and mammary cells102-103 as well as hamster liver and kidney cells.104 In contrast to an acute dose, consumption of quercetin for 10 days by rats altered the position of methylation, as tamarixetin was undetected in the circulation.92... 

Nagai, M., Conney, A.H., and Zhu, B.T., Strong inhibitory effects of common tea catechins and bioflavonoids on the O-methylation of catechol estrogens catalyzed by human Ever cytosolic catechol-O-methyltransferase, Drug Metab. Dispos., 32,497, 2004. 

R24. Ruiz-Larrea, M. B., Martin, C., Martinez, R., Navarro, R., Lacort, M., and Miller, N. J., Antioxidant activities of estrogens against aqueous and lipophilic radicals. Differences between phenol and catechol estrogens. Chem. Phys. lipids 105, 179—188 (2000). 

TCDD in intact female rats, but not male rats or ovariectomized female rats, could be explained in part by the formation of toxic catechol estrogens from 17 -estradiol, a reaction catalyzed by CYP1A2 (Lucier et al. 1993a). This is also consistent with the finding that CYP1A2 is induced in liver but not in extrahepatic organs. 

Bilirubin, estradiol (3-OH), 2-OH-estrone, 2-OH-estradiol trans-retinoic acid, Catechol estrogens (2-OH 4-OH)15-OH-eicosa-tetraenoic acid, 20-OH-eicosa-tetraenoic acid, arachidonic acid, prostaglandin B1... 

Substrates of COMT include xenobiotics catechols, catecholamines, and catechol estrogens. Three functional classes of chemicals are known to inhibit COMT. S-Adenosyl-I-homocysteine (SAH) is a potent inhibitor of COMT as well as the other SAM-dependent methyltransferases. Inhibition results from SAH binding to the SAM binding site on the enzyme. Certain divalent ions such as Ca+2 and trivalent metal ions such as the salts of lanthanides, neodymium, and europium are excellent inhibitors of COMT. A number of catechol-type substrates such as pyrogallol, fla-vonoids, pyrones, pyridenes, hydroxyquiolines, 3-mercaptotyramine, and tropolones are irreversible inhibitors of COMT. 

Endogenous Exposure Estrogen, catechol estrogen-3,4-quinones... 

Catechol O-methyltransferase plays an important role in the catabolism of catecholamine neurotransmitters such as dopamine, norepinephrine, and epinephrine, and inactivation of catechol estrogens and catechol xenobiotics. Several different methods have been developed. 

Lindberg et al. [7] performed a derivatization of budesonide with acetic anhydride to the 21-acetyl derivative in order to enhance its ionization efficiency in TSP ionization. The same procedure in combination with positive-ion APCI was used by others for budesonide [27], and the catechol estrogens 2- and 4-hydroxy-estrone and 2- and 4-hydroxy estradiol in rat brain [28]. 

E. Rathahao, A. Page, I. Jouanin, A. Paris, L. Debrauwer, LC coupled to negative ESI ion trap MS for the identification of isomeric glutathione conjugates of catechol estrogens, Int. J. Mass Spectrom., 231 (2004) 119. 

Existence of catechol estrogens was postulated as early as the late 1930s from observations such as that made by Dingemanse and Laqueur who reported the... 

Catechol estrogens are formed from the naturally occurring estrogens (estradiol-17)S and estrone) in the central nervous system (e.g., hypothalamus and cerebral cortex) and the anterior pituitary and to a lesser extent in other organs. 17)S-Oxidoreductase and cytochrome P450 (CYPlAl and CYPIBI) are enzymes that convert estrogens to catechol metabolites. 

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