Combined Experimental and Computational Study of V-Substituted Lindqvist Polyoxotungstate: Screening by Docking for Potential Antidiabetic Activity

In the current work, a novel vanadotungstate compound, (C6H9N2)4[V2W4O19]·2H2O (1), is isolated by a simple stepwise synthesis method and characterized by a combined experimental and computational study. Molecular docking is conducted for the first time for this kind of substituted Lindqvist polyoxometalates to elucidate for potential antidiabetic activity. Hence, the modeling results revealed a significant docking score of the reported compound to bind to the active sites of α-glucosidase with the lowest binding energy of -5.7 kcal/mol, where the standard drug acarbose (ACB) had -4.6 kcal/mol binding energy. The stability of binding was enhanced by strong H-bonding, van der Waals, and electrostatic interactions occurring in the three-dimensional (3D) supramolecular network of polyanionic vanadotungstate subunits templated with organic moieties as shown by X-ray diffraction and Hirshfeld analyses. Furthermore, density functional theory (DFT) calculations supported with photophysical measurements are also discussed to predict the most chemical and biological reactivity. In this view, the complete description of electronic and biological features of (1) is enhanced by determination of the highest occupied molecular orbital (HOMO)/least unoccupied molecular orbital (LUMO) energy, electronic density, ionization potential, electron affinity, etc. These chemical descriptors, intermolecular interactions, docking score, and binding free energy estimation are essential in understanding the reactivity of this bioactive compound offering potential inhibition of the α-glucosidase enzyme.

Synthesis, Characterization, Fluorescence and Antibacterial Activity of the Re(VII) Complex [ReO3(phen)(H2PO4)]・H2O

Single crystals of a Re(VII) complex, the dihydrogenophosphato phenanthroline trioxo-rhenium monohydrate of formula [ReO3(phen)(H2PO4)]⋅H2O (phen=1,10-phenanthroline), were prepared in aqueous solution. X-Ray analysis shows that it crystallizes in the monoclinic space group P21/c with the unit cell parameters: a=8.611(2), b=13.881(2), c=14.502(4) Å , β =120:87(2)°, V =1487.9(6) Å3 and Z = 4. In the neutral complex, the rhenium is in the oxidation state +VII, coordinated by two nitrogen atoms of the bidentate phen, three terminal oxygen atoms and, for the first time, one oxygen atom of the mono-deprotonated phosphoric acid ligand H2PO- 4 , forming a squarebased bipyramidal coordination geometry. The thermal stability, IR, UV/Vis and fluorescence spectroscopic properties are given. The complex shows antimicrobial activity against five different microbes.