In this study, we characterized the enzymology of cytosolic catechol-O-methyltransferase (COMT)-catalyzed …

• Abstract
• Introduction
• Materials and Methods
• Results
• Discussion
• References
• Figures
• Tables

• Bertoldi M, Gonsalvi M and Voltattorni CB (2001) Green tea polyphenols: novel irreversible inhibitors of dopa decarboxylase. Biochem Biophys Res Commun  284: 90-93
• Chan DK, Woo J, Ho SC, Pang CP, Law LK, Ng PW, Hung WT, Kwok T, Hui E, Orr K, et al. (1998) Genetic and environmental risk factors for Parkinson's disease in a Chinese population. J Neurol Neurosurg Psychiatry  65: 781-784
• Checkoway H, Powers K, Smith-Weller T, Franklin GM, Longstreth WT, Jr and Swanson PD (2002) Parkinson's disease risks associated with cigarette smoking, alcohol consumption and caffeine intake. Am J Epidemiol  155: 732-738
• Chen L, Lee MJ, Li H and Yang CS (1997) Absorption, distribution, elimination of tea polyphenols in rats. Drug Metab Dispos  25: 1045-1050
• Cheng X (1995) Structure and function of DNA methyltransferases. Annu Rev Biophys Biomol Struct  24: 293-318
• Dulloo AG, Seydoux J, Girardier L, Chantre P and Vandermander J (2000) Green tea and thermogenesis: interactions between catechin-polyphenols, caffeine and sympathetic activity. Int J Obes Relat Metab Disord  24: 252-258
• Gugler R and Dengler HJ (1973) Inhibition of human liver catechol-O-methyltransferase by flavonoids. Naunyn-Schmiedeberg's Arch Pharmacol  276: 223-233
• Hong JY, Pan JM, Ning SM and Yang CS (1989) Molecular basis for the sex-related difference in renal N-nitrosodimethylamine demethylase in C3H/HeJ mice. Cancer Res  49: 2973-2979
• Keranen T, Gordin A, Karlsson M, Korpela K, Pentikainen PJ, Rita H, Schultz E, Seppala L and Wikberg T (1994) Inhibition of soluble catechol-O-methyltransferase and single-dose pharmacokinetics after oral and intravenous administration of entacapone. Eur J Clin Pharmacol  46: 151-157
• Kida K, Suzuki M, Matsumoto N, Nanjo F and Hara Y (2000) Identification of biliary metabolites of ()-epigallocatechin gallate in rats. J Agric Food Chem  48: 4151-4155
• Kohri T, Nanjo F, Suzuki M, Seto R, Matsumoto N, Yamakawa M, Hojo H, Hara Y, Desai D, Amin S, et al. (2001) Synthesis of ()-[4-3H]epigallocatechin gallate and its metabolic fate in rats after intravenous administration. J Agric Food Chem  49: 1042-1048
• Lautala P, Ulmanen I and Taskinen J (1999) Radiochemical high-performance liquid chromatographic assay for the determination of catechol O-methyltransferase activity towards various substrates. J Chromatogr B Biomed Sci Appl  736: 143-151
• Lautala P, Ulmanen I and Taskinen J (2001) Molecular mechanisms controlling the rate and specificity of catechol O-methylation by human soluble catechol O-methyltransferase. Mol Pharmacol  59: 393-402
• Levites Y, Youdim MB, Maor G and Mandel S (2002) Attenuation of 6-hydroxydopamine (6-OHDA)-induced nuclear factor-kappaB (NF-kappaB) activation and cell death by tea extracts in neuronal cultures. Biochem Pharmacol  63: 21-29
• Li C, Meng X, Winnik B, Lee MJ, Lu H, Sheng S, Buckley B and Yang CS (2001) Analysis of urinary metabolites of tea catechins by liquid chromatography/electrospray ionization mass spectrometry. Chem Res Toxicol  14: 702-707
• Lu H, Meng X, Li C, Sang S, Patten C, Sheng S, Hong J, Bai N, Winnik B, Ho CT and Yang CS (2003) Glucuronides of tea catechins: enzymology of biosynthesis and biological activities. Drug Metab Dispos  31: 452-461
• Mannisto PT and Kaakkola S (1999) Catechol-O-methyltransferase (COMT): biochemistry, molecular biology, pharmacology and clinical efficacy of the new selective COMT inhibitors. Pharmacol Rev  51: 593-628
• Meng X, Lee MJ, Li C, Sheng S, Zhu N, Sang S, Ho CT and Yang CS (2001) Formation and identification of 4'-O-methyl-()-epigallocatechin in humans. Drug Metab Dispos  29: 789-793
• Meng X, Sang S, Zhu N, Lu H, Sheng S, Lee MJ, Ho CT and Yang CS (2002) Identification and characterization of methylated and ring-fission metabolites of tea catechins formed in humans, mice and rats. Chem Res Toxicol  15: 1042-1050
• Nissinen E, Linden IB, Schultz E and Pohto P (1992) Biochemical and pharmacological properties of a peripherally acting catechol-O-methyltransferase inhibitor entacapone. Naunyn-Schmiedeberg's Arch Pharmacol  346: 262-266
• Okushio K, Suzuki M, Matsumoto N, Nanjo F and Hara Y (1999) Methylation of tea catechins by rat liver homogenates. Biosci Biotechnol Biochem  63: 430-432
• Suganuma M, Okabe S, Oniyama M, Tada Y, Ito H and Fujiki H (1998) Wide distribution of [3H]()-epigallocatechin gallate, a cancer preventive tea polyphenol, in mouse tissue. Carcinogenesis  19: 1771-1776
• Yang CS, Chen L, Lee MJ, Balentine D, Kuo MC and Schantz SP (1998) Blood and urine levels of tea catechins after ingestion of different amounts of green tea by human volunteers. Cancer Epidemiol Biomarkers Prev  7: 351-354
• Yang CS and Landau JM (2000) Effects of tea consumption on nutrition and health. J Nutr  130: 2409-2412
• Yang CS, Maliakal P and Meng X (2002) Inhibition of carcinogenesis by tea. Annu Rev Pharmacol Toxicol  42: 25-54
• Zhu BT, Patel UK, Cai MX and Conney AH (2000) O-Methylation of tea polyphenols catalyzed by human placental cytosolic catechol-O-methyltransferase. Drug Metab Dispos  28: 1024-1030
• Zhu BT, Patel UK, Cai MX, Lee AJ and Conney AH (2001) Rapid conversion of tea catechins to monomethylated products by rat liver cytosolic catechol-O-methyltransferase. Xenobiotica  31: 879-890