Bovine serum albumin-vanadium complex hybrid: Synthesis, crystal structure, SOD activities and asymmetric catalytic oxidation of sulfides

Two symmetrical double-sided Schiff base ligands, H(4)L1 and H(4)L2, were synthesized by condensation of salicylaldehyde and 2-hydroxy-l-naphthaldehyde with oxalodihydrazine, respectively. The crystal structures of their vanadium complexes were analyzed by single crystal X-ray diffraction. The interaction between the synthesized complexes and BSA was studied by various spectral methods. The binding parameters including quenching constant K-sv, binding constant K, and binding mode were obtained using fluorescence quenching method. The study shows that the quenching type was a static quenching process caused by formation of complex. The SOD activities of the complexes were determined by xanthine oxidase-NBT reduction method. The antioxidant capacity of the complexes was determined by the ABTS method. The results indicate that the activity of hybrid protein was more pronounced than that of the corresponding complex. At the same time, the hybrid protein can catalyze asymmetric oxidation of methyl phenyl sulfide. (C) 2019 Elsevier Ltd. All rights reserved.