We report the synthesis and biomimetic activity of a family of model complexes with relevance to acireductone dioxygenase (ARD), an enzyme that displays dual function based on metal identity found in the methionine salvage pathway (MSP). Three complexes with related structural motifs were synthesized and characterized derived from phenolate, and pyridine N₄O Schiff-base ligands. They display pseudo-octahedral Ni(II)-N₄O ligand coordination with water at the sixth site, in close alignment to the structure in the resting state of ARD. The three featured complexes exhibit carbon‑carbon bond cleavage activation of lithium acetylacetonate, which was used as a model enzyme substrate. Computationally derived mechanistic routes for the observed reactivity consistent with experimental conditions are herein proposed. The mechanism suggests the possibility of Ni(II)-substrate interactions, followed by oxygen insertion. These results constitute only the third functional model system of ARD, in an attempt to further advance biomimetic contributions to the ongoing debate of ARD's unique metal mediated, regioselective oxidative cleavage.

我们报告了与乙酰还原酮双加氧酶 (ARD) 相关的模型复合物家族的合成和仿生活性，ARD 是一种基于在蛋氨酸补救途径 (MSP) 中发现的金属特性而显示出双重功能的酶。合成了三种具有相关结构基序的复合物，并表征了源自酚盐和吡啶 N ₄ O 席夫碱配体的复合物。它们显示伪八面体 Ni(II)-N ₄O 配体在第六位点与水配位，与 ARD 静息状态下的结构紧密对齐。这三种特征复合物表现出乙酰丙酮锂的碳-碳键裂解活化，乙酰丙酮锂被用作模型酶底物。本文提出了用于观察到的与实验条件一致的反应性的计算得出的机械路线。该机制表明 Ni(II)-基材相互作用的可能性，然后是氧插入。这些结果仅构成了 ARD 的第三个功能模型系统，旨在进一步推进对 ARD 独特金属介导的区域选择性氧化裂解正在进行的辩论的仿生学贡献。