Synthesis, spectral characterization, SC-XRD, HSA, DFT and catalytic activity of novel dioxovanadium(V) complex with aminobenzohydrazone Schiff base ligand: An experimental and theoretical approach

Synthesis, characterization, Hirshfeld surface analysis, antioxidant and selective β-glucuronidase inhibitory studies of transition metal complexes of hydrazide based Schiff base ligand

The synthesis of N'-[(4-hydroxy-3-methoxyphenyl)methylidene] 2-aminobenzohydrazide (H-AHMB) was performed by condensing O-vanillin with 2-aminobenzohydrazide and was characterized by FTIR, high resolution ESI(+) mass spectral analysis, 1H and 13C-NMR. The compound H-AHMB was crystallized in orthorhombic Pbca space group and studied for single crystal diffraction analysis. Hirshfeld surface analysis was also carried out for identifying short interatomic interactions. The major interactions H…H, O…H and C…H cover the Hirshfeld surface of H-AHMB. The metal complexes [M(AHMB)n] where M = Co(II), Ni(II), Cu(II) and Zn(II) were prepared from metal chlorides and H-AHMB ligand. The bonding was unambigously assigned using FTIR and UV/vis analysis. The synthesized ligand H-AHMB and its metal complexes were studied for β-glucuronidase enzyme inhibition. Surprisingly the metal complexes were found more active than the parent ligand and even the standard drug. Zn-AHMB shown IC50 = 17.3 ± 0.68 µM compared to IC50 = 45.75 ± 2.16 µM shown by D-saccharic acid-1,4-lactone used as standard. The better activity by Zn-AHMB implying zinc based metallodrug for the treatment of diseases associated with β-glucuronidase enzyme. The DPPH radical scavenging activities were also studied for all the synthesized compounds. The Co-AHMB complex with IC50 = 98.2 ± 1.78 µM was the only candidate to scavenge the DPPH free radicals.

Biological and computational investigation of transition metal(II) complexes of 2-phenoxyaniline-based ligands

Aim: In the 21st century, we are witness of continuous onslaughts of various pathogen deformities which are a major cause of morbidity and mortality worldwide. Therefore, to investigate the grave for these deformities, antioxidant, anti-inflammatory and antimicrobial biological activities were carried out against newly synthesized Schiff base ligands and their transition metal complexes, which are based on newly synthesized 2-phenoxyaniline and salicylaldehyde derivatives. Materials & methods: The synthesized compounds were characterized by various physiochemical studies, demonstrating the octahedral stereochemistry of the complexes. Results: The biological assessments revealed that complex 6 (3.01 ± 0.01 μM) was found to be highly active for oxidant ailments whereas complex 14 (7.14 ± 0.05 μM, 0.0041-0.0082 μmol/ml) was observed as highly potent for inflammation and microbial diseases. Conclusion: Overall, the biological and computational studies demonstrate that the nickel(II) complex 14 can act as an excellent candidate for pathogen deformities.

Synthesis, Structural, and Intriguing Electronic Properties of Symmetrical Bis-Aryl-α,β-Unsaturated Ketone Derivatives

Three symmetrical bis-aryl-α,β-unsaturated ketone derivatives, 2,6-di((E)-benzylidene)-cyclohexan-1-one (DBC), 2,6-bis((E)-4-chlorobenzylidene)cyclohexan-1-one (BCC), and (1E,1'E,4E,4'E)-5,5'-(1,4-phenylene)bis(2-methyl-1-phenylpenta-1,4-dien-3-one) (PBMP), have been prepared using the aldol condensation approach toward ketones having two enolizable sites. The structures of DBC, BCC, and PBMP have been resolved via spectrometric methods. Moreover, the crystal structure of PBMP is determined by the single-crystal X-ray diffraction (SC-XRD) technique, which revealed that the PBMP molecular assembly is stabilized by the intermolecular C-H···O bonding and C-O···π and weak T-shaped offset π···π stacking interactions. The Hirshfeld surface analysis (HSA) of the PBMP crystal structure was performed as well, and the results were compared with the results of DBC and BCC. The density functional theory (DFT) study results revealed that the longer conjugated molecule of PBMP has smaller but still quite significant HOMO-LUMO gaps compared to the smaller molecules of BCC and DBC. The natural population analysis (NPA) and natural bonding orbital (NBO) analysis were performed. Accordingly, the hydrogen bonding and dipole-dipole interactions stabilize the crystal structures of these compounds. Additionally, the NBO analysis showed numerous high-energy stabilizing interactions for the PBMP compound due to the presence of numerous delocalized and relatively easily polarizable π-electrons, thus implying its significant thermodynamic stability. According to the global reactivity parameter (GRP) analysis, the compounds BCC and DBC are relatively stable in redox processes and have high thermodynamic stability and relatively lower reactivity in general. The molecular electrostatic potential (MEP) analysis results imply potential formation of the intermolecular hydrogen bonding and dispersion interactions, which stabilizes the crystal structures of these compounds.