PHENOXY RADICAL INTERMEDIATES IN ENZYMATIC DEGRADATION OF LIGNIN MODEL COMPOUNDS
PHENOXY RADICAL INTERMEDIATES IN ENZYMATIC DEGRADATION OF LIGNIN MODEL COMPOUNDS
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DOI：
10.1016/0304-4165(69)90046-4
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发表时间：
1969-01-01
期刊：
影响因子：
--
通讯作者：
STEELINK, C
中科院分区：
文献类型：
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作者：
CALDWELL, ES;STEELINK, C
1.1.辣根过氧化物酶和H2 O2氧化的单体和二聚体的衍生物产生长寿命的苯氧基自由基。这些都已充分其特征在于电子自旋共振光谱。氧化反应通过一系列离散步骤进行，每个步骤都涉及顺磁性中间体。最后一步导致芳核侧链的断裂，得到2，6-二甲氧基苯醌。酶的攻击是最迅速的烷基酮，其次是快速的醇和缓慢的烷烃或α-烷氧基醚。这与每种化合物产生的自由基物质的浓度平行。生物钟机制似乎调解这些反应。木腐真菌降解木质素的过程可能是酚氧化酶催化的一系列单电子步骤的结果。
1.1. Oxidation of monomeric and dimersic syringly derivatives with horseradish peroxidase and H2O2yielded long-lived phenoxy radicals. These have been fully characterized by electron spin resonance spectrometry. The oxidation reaction proceeded by a sequence of discrete steps, each involving a paramagnetic intermediate. The final step resulted in the clevage of the side chain from the aromatic nucleus to yeild 2,6-dimethoxybenzoquinone. Enzymatic attack was most rapid with alkyl syringly ketones, less rapid with syringly alcohols and slow with syringly alkanes or α-alkoxy ethers. This parallel the concentration of the radical species produced for each compound. A biological clock mechanism appeared to mediate these reactions.2.2. The depolymerization of lignin by wood-rotting fungi may result from a series of one-electron steps catalyzed by phenol oxidases.