Dioxygenation of Flavonol Catalyzed by Copper(II) Complexes Supported by Carboxylate-Containing Ligands: Structural and Functional Models of Quercetin 2,4-Dioxygenase
Dioxygenation of Flavonol Catalyzed by Copper(II) Complexes Supported by Carboxylate-Containing Ligands: Structural and Functional Models of Quercetin 2,4-Dioxygenase
复制标题
含羧酸配体支持的铜 (II) 配合物催化黄酮醇的双加氧：槲皮素 2,4-双加氧酶的结构和功能模型
DOI：
10.1002/ejic.201700245
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发表时间：
2017
影响因子：
2.3
通讯作者：
Shinobu Itoh
中科院分区：
文献类型：
--
作者：
Ying-Ji Sun;Pei Li;Qian-Qian Huang;Jian-Jun Zhang;Shinobu Itoh
To obtain insights into the role of the carboxylate group of Glu73 in the active site of quercetin 2,4‐dioxygenase (2,4‐QD), the copper(II) complexes [CuIILn(AcO)] [1(Ln=L1),2(Ln=L2),3(Ln=L3), and4(Ln=L4)] supported by a series of carboxylate‐containing ligands [L1H = 2‐{[bis(pyridin‐2‐ylmethyl)amino]methyl}benzoic acid;L2H = 3‐{[bis(pyridin‐2‐ylmethyl)amino]methyl}benzoic acid,;L3H = 2‐({bis[2‐(pyridin‐2‐yl)ethyl]amino}methyl)benzoic acid;L4H = 3‐({bis[2‐(pyridin‐2‐yl)ethyl]amino}methyl)benzoic acid] as well as the ternary CuIIflavonolate (fla–) complexes [CuIILn(fla)] [5(Ln=L1),6(Ln=L2),7(Ln=L3), and8(Ln=L4)] were synthesized and characterized as structural and functional models for the active site of 2,4‐QD. The ternary complexes [CuIILn(fla)] showed different reactivities in the dioxygenation of bound flavonolate to benzoic acid, salicylic acid, andN,N‐dimethylbenzamide at 75–90 °C (single‐turnover reaction) in the order5>>7>8≈6. A similar reactivity tendency was found in the catalytic dioxygenation of the substrate flavonol (multiturnover reaction) by the binary complexes. The different reactivities of the copper complexes could be attributed to the different Lewis acidities of the copper(II) ions induced by the different coordination environments of the ligands. The results will provide important insights into the pivotal catalytic role of the carboxylate group of Glu73 in 2,4‐QD.
