Dioxomolybdenum(VI) complexes of 2-hydroxy-4-benzyloxybenzaldehyde thiosemicarbazones alkylated via N or S atoms. Synthesis, characterization, antioxidant and xanthine oxidase inhibition performance

•Dioxomolybdenum (VI) complexes of 2‑hydroxy-4-benzyloxybenzyldene N- or S-alkyl substituted thiosemicarbazones have been prepared.•Complex IV exhibited good antioxidant capacity with CUPRAC.•All compounds screened for their xanthine oxidase inhibiton acitivity.•Ligands containing free NH2 group were more active XO inhibitors than the complexes. Using the synthesis method, we produced a series of 2‑hydroxy-4-benzyloxybenzylidene N- or S-alkyl chains substituted thiosemicarbazones and their dioxomolybdenum(VI) complexes containing long alkyl chains (pentyl, hexyl, heptyl, and octyl). A series of dioxomolybdenum(VI) complexes with 2‑hydroxy-4-benzyloxybenzylidene thiosemicarbazones substituted by long alkyl chains, pentyl, hexyl, heptyl, and octyl, on the N- or S atoms were synthesized. Analytical and spectroscopic techniques were used to characterize the compounds. As a representative molecule, the molecular structure of complex I named cis-dioxo-(N1–2‑hydroxy-4-benzyloxybenzylidene-N4-pentylthiosemicarbazonato)-methanol-molybdenum(VI) was identified by single crystal X-ray diffraction. Using the method of cupric reducing antioxidant capacity, the ONN donor thiosemicarbazones (LV-LVIII) were found to have higher trolox equivalent antioxidant capacity values than those with ONS (LI-LIV). Furthermore, the inhibitory activities of xanthine oxidase and the scavenging effects of the compounds on the hydroxyl radical were examined. Complex VII was the most effective XO inhibitor with an IC50 value of 33.41 μM in similar to allopurinol as a potential XO inhibitor (IC50: 33.14 μM), and it can be used as XO inhibitor in treatment of XO-based disorders. [Display omitted]