Synthesis, characterization, anti‐inflammatory and analgesic activity of transition metal complexes of 3‐[1‐(2‐hydroxyphenyl) ethylideamino]‐2‐phenyl‐3,4‐dihydroquinazolin‐4(3H)‐one

Abstract

A new quinazolinone derivative, 3-[1-(2-hydroxyphenyl)ethylideamino]-2-phenyl-3,4-dihydroquinazolin-4(3H)-one (LH) wassynthesized by the condensation of 2-hydroxyacetophenone-2-aminobenzoylhydrazone and benzaldehyde. The cyclization to form 1,2-dihydroquinazolinone was confirmed by IR, 1D and 2D HETCOR studies. Coordination compounds of Co(II), Ni(II), Cu(II) and Zn(II) of LH were synthesized and characterized using various physico-chemical studies like stoichiometric, conductivity, magnetic moment measurements and spectral techniques such as IR, NMR, UV-vis and EPR spectroscopy. The elemental analysis and thermal studies suggested a general stoichiometry [M(HEPDQ)Cl] for all the complexes. A four-coordinate geometry was assigned to all the complexes. The complexes along with the parent ligand were screened for their anti-inflammatory activity, using carrageenan-induced rat paw edema, and for their analgesic activity by Eddy's hot plate method. The activity of the ligand was enhanced on complexation with metal ions. This enhanced activity was attributed to the increased lipophilic nature of the complexes. Notable anti-inflammatory activity was observed for Ni(II), Cu(II) and Zn(II) complexes. The analgesic activity of the ligand was greater than the standard at 60 min. and at a 10 mg kg −1 dose, whereas the activity of Ni(II) and Cu(II) complexes at 10 mg kg −1 dose was comparable with the standard used.

Molecular structure, molecular docking, thermal, spectroscopic and biological activity studies of bis‐Schiff base ligand and its metal complexes

“…The chemical structures of a novel bis‐Schiff base ligand and its mononuclear metal complexes were characterized using various physicochemical techniques. The present study revealed an octahedral geometry around the M(II)/M(III) complexes as indicated from diffuse reflectance and magnetic moment measurements . IR spectra revealed that the bis‐Schiff base ligand acts as a tetradentate ligand and its manner of coordination is through the nitrogen atoms of the azomethine (CH═N) and etheric O groups.…”

“…From the data listed in Table , it was found that the Cu(II) complex had moderate inhibitory activity (28 and 29 mm) for E. coli and P. vulgaris , respectively. On the other hand, it registered high MIC 50 (>100 mg ml −1 ) for both microorganisms . But the Mn(II) complex has poorer inhibitory activity, where the diameters of the inhibition zone are 24 and 22 mm for E. coli and P. vulgaris , respectively.…”

New mononuclear Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) complexes incorporating 4‐{[(2 hydroxyphenyl)imino]methyl}phenyl‐4‐methylbenzenesulfonate (HL): Synthesis, characterization, theoretical, anti‐inflammatory, and molecular docking investigation

“…The 1H‐NMR spectra of the synthesized Schiff‐base ligand revealed a characteristic signal at 9.98 ppm (s, 1H), which is attributable to the phenolic (–OH) proton (Figure S1); however, this signal is absent in the spectrum of its Ni(II) and zinc(II) complexes (Figure S3). This indicates that following deprotonation, the phenolic group (–OH) is coordinated with the metal ions 51 . In the Schiff‐base ligand, the distinctive signal of the azomethine proton (–CH═N) occurred at 8.97 ppm (s, 1H) (Figure S1).…”

Synthesis, spectral, thermal behaviors, and antimicrobial studies of some nanostructure five coordinated Hg(II) complexes

“…The studies show when Schiff base ligands bind to metal ions, their antimicrobial and anticancer activities will be enhanced [10][11][12][13]. Schiff base complexes have been attracted many attention due to their good antimicrobial, antibacterial, antifungal, antiviral, antimycobacterial, anti-flammatory, analgesic, antitubercular, and antioxidant activities [14][15][16][17][18][19]. Furthermore, the interaction of these complexes with DNA has gained much attention due to their potentials as new therapeutic agents [20].…”