[Competitive inhibition of catechol-O-methyltransferase by the tetrahydroisoquinoline alkaloids salsolidine and 1-carboxysalsoline].
The tetrahydroisoquinoline alkaloids salsolidine (1-methyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline) and 1-carboxysalsoline (1-carboxy-1-methyl-6-hydroxy-7-methoxy-1,2,3,4-tetrahydroisoquinoline), which are themselves not substrates for the enzyme catechol-O-methyltransferase, are - contrary to a hitherto existing view - able to inhibit competitively the methylation of the catecholamine metabolite 3,4-dihydroxybenzoic acid by the enzyme enriched from rat liver. The inhibitor constants were determined to be Ki = 0.19 mM for salsolidine and Ki = 0.44 mM for 1-carboxysalsoline.
Sanft
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Abteilung Physiologische Chemie der Universität Ulm, Bundesrepublik Deutschland.
Thomas
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H
D000818:Animals; D001667:Binding, Competitive; D065098:Catechol O-Methyltransferase Inhibitors; D007546:Isoquinolines / Q000494:pharmacology*; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D051381:Rats; D012490:Salsoline Alkaloids / Q000494:pharmacology*; D044005:Tetrahydroisoquinolines
D065098:Catechol O-Methyltransferase Inhibitors; D007546:Isoquinolines; D012490:Salsoline Alkaloids; D044005:Tetrahydroisoquinolines; C059667:1-carboxysalsoline; C059665:salsolidine
Kompetitive Hemmung der Catechol-O-Methyl-transferase durch die Tetrahydroisochinolin-Alkaloide Salsolidin und 1-Carboxysalsolin.