真菌漆酶介导自由基偶联和接枝反应在绿色化学中的应用

漆酶(p-苯二醇:分子氧氧化还原酶;EC 1.10.3.2)是自然界中普遍存在的一类胞外含铜多酚氧化还原酶.漆酶能够以环境中氧分子作为电子接受体,催化4个底物分子的单电子氧化形成4个相应的反应活性自由基或醌类中间体,随后这些活性中间体在酶促位点外发生步进式偶联反应,生成多种具有复杂结构的大分子C—C、C—O—C或C—N—C共价聚合产物.该反应过程中仅生成唯一副产物水,具有反应温和、底物广谱、催化效率高、操作可控和经济环保等优点.目前,真菌漆酶介导低分子有机物和高分子化合物的自由基偶联和接枝反应已经被应用于生物技术领域,该技术克服了传统物理化学方法存在的弊端,在保护人群健康和生态安全等方面具有广泛地应用前景和商业价值.本文详细地概述了真菌漆酶催化不同底物分子的自由基偶联和接枝反应在环境修复、生物监测、食品加工、纤维改性、纺织染色、制药行业和有机合成等绿色化学中的最新研究进展,旨在为开发和拓展真菌漆酶在绿色化学技术领域中的多功能应用提供科学的理论依据和技术指导.

Prospects and applications of fungal laccase-mediated the radical coupling and grafting processes in green chemosynthesis

Laccases(p-diphenol:dioxygen oxidoreductases;EC 1.10.3.2)are a category of blue extracellular multi-copper oxidases which are extensively distributed in bacteria,fungi,higher plants,and insects.Laccases have received great attention because of their broad substrate specificity in oxidizing phenolic and non-phenolic compounds.Thus,they can be regarded as the ultimate"green catalysts"in the biotechnology fields.It is well-documented that laccase can mediate the one-electron oxidation of four hydrogen-donating substrate molecules at the T1 copper site(ⅠCu²⁺)to produce four reactive radical or quinone intermediates,leading to the four-electron reduction of molecular oxygen at the T2;T3 copper site(ⅡCu²⁺/ⅢCu²⁺)into two water molecules.Subsequently,these reactive intermediates can further undergo spontaneous(non-enzymatic)coupling reactions to generate various complex polymeric structures via radical-based C-C,C-O-C,or C-N-C covalent coupling mechanism.This process has the advantages of mild reaction conditions,high catalytic performance,simplicity,cost-effectiveness,and environmental friendliness,and has become an eco-friendly substitute for the conventional chemical reactions.In fungi,laccases are present in Ascomycetes,Deuteromycetes,and Basidiomycetes,and are particularly abundant in many white-rot fungi.These laccases have an average molecular weight between 50 and 130 kDa.At present,fungal laccase-mediated the radical coupling and grafting reactions of low-molecular-weight organics and high-molecular-weight compounds have been used to different green chemosynthesis fields,which exhibit widely applicable values and development prospects.In this review,many potential applications of fungal laccase-catalyzed the radical coupling and grafting processes of substrate molecules in biotechnological fields,such as environmental restoration,biological monitoring,food processing,fibre modification,textile dyeing,pharmaceutical industry,and organic synthesis,are systematically summarized and outlooked.This aims of review to provide a scientific theoretical basis and technical guidance for the multifunctional applications of fungal laccase in green chemosynthesis.