高等学校化学学报 ›› 1995, Vol. 16 ›› Issue (11): 1731.

• 论文 • 上一篇    下一篇

漆树漆酶的催化氧化作用(X)──叔丁基儿茶酚类底物的漆酶催化氧化和漆酶的微环境效应

王光辉, 花建丽   

  1. 武汉大学化学系, 武汉, 430072
  • 收稿日期:1994-11-24 修回日期:1995-08-09 出版日期:1995-11-24 发布日期:1995-11-24
  • 通讯作者: 王光辉,男,57岁,教授.
  • 作者简介:王光辉,男,57岁,教授.
  • 基金资助:

    国家自然科学基金

Catalyzed Oxidation by Rhus Vernicifera Laccaxe(X)──The Laccase-catalyzed Oxldation of Cateckols Containing tert-Butyl Group and the Microenvironment Effect of Rhus Laccase

WANG Guang-Hui, HUA Jian-Li   

  1. Department of Chemistry, Wuhan University, Wuhan, 430072
  • Received:1994-11-24 Revised:1995-08-09 Online:1995-11-24 Published:1995-11-24

摘要: 对6个含叔丁基的儿茶酚类底物的离解和漆酶催化氧化反应进行了考察。结果表明:叔丁基的存在,有利于增进对底物的结合,并可以利用漆酶活性中心周围提供的pH环境和质子载体性质,促进底物的离解,使这类底物能在远低于其一级离解的弱酸性环境中进行反应。由于叔丁基的特性和漆酶的微环境效应的共同作用,这些底物在pH=6.0的水溶液环境中都能顺利地氧化成相应邻醌,并具有合成价值。ESR结果证明:这些底物在弱酸性条件下的漆酶催化反应经历了质子转移和单电子氧化步骤。

关键词: 漆树漆酶, 叔丁基儿茶酚类, 微环境效应, 邻苯半醌自由基阴离子, 酶法合成

Abstract: The dissociation and Laccase-catalyzed oxidation of six catechols containing tertbutyl group were investigated spectrophotometrically under pH 6.0~8.0 conditions. The studies show that in the presence of tert-butyl group,not only to bonding of these substrates is improved,but through the influence of the microenvironment effect of laccase,the dissociation of these substrates is promoted and the enzymatic reaction can take place under condition of weak acidity(pH6.0), which is far from the first-order dissociation of these sub-strates. Because of the influence of the characterization of tert-butyl group and the microenvironment effect of laccase, these substrates can be transformed by laccase into corresponding o-quinones at pH6.0,and they have a synthetic value,Moreover,using ESR-spin stabilization technique,the o-semiquinone anion-radicals generated during the enzymatic reaction were trapped in pH6.0,and the superfine structures of the ESRspectra were discussed.The result demonstrate that the Laccase-catalyzed reaction of these substrates underwent the stage of the proton transportation and one-electron oxidation.

Key words: Rhus vernicfera laccase, Catechols containing tert-butyl group, Microenvironment effect, o-Semiquinone anion-radicals, Enzymatic synthesis

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