Synthesis and Evaluation of Structural and Functional Biomimetic Models of Oxidase-Type Metalloenzymes Based on Polynuclear Compounds with Copper (II) and Manganese (II) Ions

Abstract

Biomimetic compounds are an alternative for to the limited action and fragile nature of enzymes. This work deals with the synthesis, characterization and evaluation of catalytic activity of two new biomimetic models for the active centers of ascorbate oxidase and catalase. [Cu3(S,S(+)cpse)3(H2O)3][Cu3(R,R(-)cpse)3(H2O)3]·17H2O (model for ascorbate oxidase, 1), and [Mn2(S,S(+)Hcpse)4(NaClO4)2(NaOH)(CH4O)]n·[(C2H6O)2]n·[(CH4O)2]n (model for catalase, 2) were prepared through the synchronic method (yields > 78%). The compound 1 has electronic and optical characteristics for racemic compound. The magnetic properties and electrochemical behavior evidence electronic transfer between metal centers. Meanwhile, the compound 2 showed polymeric properties in solid state and dimeric behavior in solution. Compound 1 was able to effectively catalyze the oxidation of ascorbic acid to dehydroascorbic acid (65.6% and 78.24% for racemic and enantiomeric pure compounds) showing structural and functional similarity to the natural enzyme. Besides, Compound 2 catalyzed the decomposition of hydrogen peroxide toward oxygen and water molecules (45%), evidencing that the prepared complex mimics the action of catalases. These two biomimetic models are relationship between them for the structural ligands, the coordination form to metal center and the catalytic activity as oxidase. This research shows the relationship with the design, evaluation, and comprehension of fundamentals aspects for the biomimetic models of active center of metalloenzymes that have importance for biological and industrial processes.