Catalytic studies of the dinuclear copper complex [Cu2(PTU-S-PTU)2] (PTU: Propylthiouracil) bioinspired in trisulfide bridges located in proteins

J. CARO RAMIREZ; M. ROQUE BORDA ; N. MARTINI; J. E. PARENTE ; N. M. URQUIZA; O. E. PIRO; G. A. ECHEVERRÍA; P. A. M. WILLIAMS; E. G. FERRER

Montevideo

Congreso; VII Latin American Meeting on Biological Inorganic Chemistry, VII LABIC; 2020

Universidad de la República

Catalysis is an important area of chemistry that can solve future problems related to new materials for industry, medicine and energy resources. Researchers have focused attention on biocatalysis, organocatalysis or the use of metabolizable metal complexes [1]. Because of the restrictions on the use of natural or artificial metalloenzymes the so-called SIMCats (small-molecule intracellular metal catalysts) became a relevant topic in the integration of inorganic catalysts with living systems [2]. In connection with our previous work [2], we present the synthesis and characterization of a Cu(II)-dinuclear complex obtained by in situ transformation of the propylthiouracil (PTU) ligand formulated as [Cu2(PTU-S-PTU)2] (C28H36Cu2N8O4S6), as well as the simulation of peroxidase enzymes and their relationship with the antithyroid activity.The crystal structure (X-ray diffraction) shows a dimeric PTU ligand with a coordination sphere( CuO 2 S(S 2 )N 2 around each copper atom, giving rise to a central symmetric dinuclear complex(Reflectance and UV Vis (DMA) : 700, 550, 300 and 228 nm; FTIR: 2960, 2928, 2870, 1597, 1533,1514, 1487, 1405, 1276, 1178, 1007, 839, 508, 493 cm-1 ). The dinuclear complex is stable in solution and retains the stru cture of the solid . Catalytic determinations (Michaelis Menten) based on the peroxidase activity model (using phenol red as substrate) indicate that the complex is capable of simulating the action of bromoperoxidases (V max = 1.4358 µM/s; K m = 127 33 µM) an d it is then suggested that it can act like an antithyroid compound removing the required substrate (H2O2) like lactoperoxidase. Additionally, bioavailability studies indicate that the complex is able to be transported by bovine serum albumin (K a (37 degrees Celcius) = 1.8 x10 6 M-1 ; number of binding sites: n = 1 ; deltaG = 29.24 k J/mol).