漆酶介导生物体内酚类氧化偶联的基本原理及其在绿色合成中的应用

漆酶(Laccase,p-diphenol dioxygen oxidoreductases,EC 1.10.3.2)是一类包含三核铜簇位点的多酚氧化还原酶,广泛存在于细菌、真菌、高等植物和昆虫体内。该类酶不仅能够促进生态系统中高分子木质素和腐殖质聚合物的生物分解,还可以催化有机体内单酚和多酚类化合物参与黑色素、木质素、黄酮类和角质层等功能酚聚合物的生物合成。漆酶介导有机物的分解代谢和合成代谢机制有益于生态环境中碳循环和生物形态发生变化。在生物体内,漆酶催化天然酚类单电子氧化形成苯氧活性自由基或醌类中间体,随后这些活性中间体发生自我偶联或交叉偶联反应,生成多种结构复杂的大分子C-C、C-O-C或C-N-C功能聚合产物。因此,通过人工模拟漆酶催化生物体内的绿色合成代谢机理和路径,合理设计和定向改造漆酶在生物体外催化酚类底物偶联形成大分子功能聚合产物的结构和特性,有望为拓展和研发漆酶在绿色合成化学中的多功能应用提供丰富的参考价值和新颖的见解思路。

Laccase-Mediated Oxidative Coupling of Phenolic Compounds in vivo:from Fundamentals to Multifunctional Applications in Green Synthesis

Laccases(p-diphenol dioxygen oxidoreductases,EC 1.10.3.2)are polyphenol oxidoreductase containing trinuclear copper cluster sites in nature and are presented widely in fungi,bacteria,plants,and insects.These enzymes can not only promote the bio-decomposition of polymer lignin and humus in ecosystem,but also catalyze the participation of monophenols and polyphenols in the biosynthesis of functional phenolic polymers such as melanin,lignin,flavonoids and keratin.The decomposition metabolism and anabolism mediated by laccases are beneficial to global carbon cycling and morphogenesis variations in ecosystem.In organisms,laccase catalyzes the single electron oxidation of natural phenols to form phenoxy active radicals or quinones intermediates,which then undergo self-coupling or cross-coupling reactions to form a variety of complex macromolecules C-C,C-O-C or C-N-C functional polymerization products.Thus,through mimicking laccase-catalyzing biosynthetic pathways in laboratory,we intend to reasonably design and directly modify the structures and functions of polymerization products by laccase-mediating the radical coupling of phenolic substrates in vitro synthetic processes,aiming at providing a reference and novel ideas for expanding and developing the multifunctional applications of laccase in green chemosynthesis.