Rompel A, Fischer H, Meiwes D, Büldt-Karentzopoulos K, Magrini A, Eicken C, Gerdemann C, Krebs B
Anorganisch-Chemisches der Universität Münster, Germany.
FEBS Lett. 1999 Feb 19;445(1):103-10. doi: 10.1016/s0014-5793(99)00106-4.
The substrate specificity of catechol oxidase from Lycopus europaeus towards phenols is examined. The enzyme catalyzes the oxidation of o-diphenols to o-quinones without hydroxylating monophenols, the additional activity of tyrosinase. Substrates containing a -COOH group are inhibitors for catechol oxidase. The products of enzymic oxidation of caffeic acid were analyzed and isolated by HPLC with diode array detection. The neolignans of the 2,3-dihydro-1,4-benzodioxin type (3, 6-8), 6,7-dihydroxy-1-(3,4-dihydroxyphenyl)-2,3-dicarboxy-1,2-dihydro naphthaline (1) 6,7-dihydroxy-1-(3,4-dihydroxyphenyl)-3-carboxynaphthaline (5) and 2,6-bis-(3',4'-dihydroxyphenyl)-1-carboxy-3-oxacyclo-(3,0)-pent an-2-on-1-ene (4) were formed. A reaction mechanism for the formation of (1, 4 and 5) is discussed.
研究了欧地笋中儿茶酚氧化酶对酚类的底物特异性。该酶催化邻二酚氧化为邻醌，而不会使单酚羟基化，这是酪氨酸酶的额外活性。含有 -COOH 基团的底物是儿茶酚氧化酶的抑制剂。通过带有二极管阵列检测的高效液相色谱法分析并分离了咖啡酸的酶促氧化产物。形成了 2,3-二氢-1,4-苯并二恶英型新木脂素（3, 6 - 8）、6,7-二羟基-1-(3,4-二羟基苯基)-2,3-二羧基-1,2-二氢萘（1）、6,7-二羟基-1-(3,4-二羟基苯基)-3-羧基萘（5）和 2,6-双-(3',4'-二羟基苯基)-1-羧基-3-氧杂环-(3,0)-戊-2-酮-1-烯（4）。讨论了（1、4 和 5）形成的反应机制。
