Density functional theory/B3LYP study of nanometric 4‐(2,4‐dihydroxy‐5‐formylphen‐1‐ylazo)‐N‐(4‐methylpyrimidin‐2‐yl)benzenesulfonamide complexes: Quantitative structure–activity relationship, docking, spectral and biological investigations

Abstract

New metal ion complexes were isolated after coupling with 4-(2,4-dihydroxy-5formylphen-1-ylazo)-N-(4-methylpyrimidin-2-yl)benzenesulfonamide (H 2 L) drug ligand. The structural and molecular formulae of drug derivative and its complexes were elucidated using spectral, analytical and theoretical tools. Vibrational spectral data proved that H 2 L behaves as a monobasic bidentate ligand through one nitrogen from azo group and ionized hydroxyl oxygen towards all metal ions. UV-visible and magnetic moment measurements indicated that Fe(III), Cr(III), Mn(II) and Ni(II) complexes have octahedral configuration whereas Cd(II), Zn(II) and Co(II) complexes are in tetrahedral form. The Cu(II)complex has square planar geometry as verified through electron spin resonance essential parameters. X-ray diffraction data indicated the amorphous nature of all compounds with no regular arrangement for the solid constituents during the precipitation process. Transmission electron microscopy images showed homogeneous metal ion distribution on the surface of the complexes with nanometric particles. Coats-Redfern equations were applied for calculating thermo-kinetic parameters for suitable thermal decomposition stages. Gaussian09 and quantitative structure-activity relationship modelling studies were used to verify the structural and biological features. Docking study using microorganism protein receptors was implemented to throw light on the biological behaviour of the proposed drug. The investigated ligand and metal complexes were screened for their in vitro antimicrobial activities against fungal and bacterial strains. The resulting data indicated that the investigated compounds are highly promising bactericides and fungicides. The antitumour activities of all compounds were evaluated towards human liver carcinoma (HEPG2) cell line.

Nano‐synthesis and spectral, thermal, modeling, quantitative structure–activity relationship and docking studies of novel bioactive homo‐binuclear metal complexes derived from thiazole drug for therapeutic applications

“…The appearance of ν as (OCO) and ν s (OCO) bands at 1658 and 1444 cm −1 , respectively, confirmed the unidentate mode of the acetate group for Cu(II) complex ( 3 ). New bands appearing at around 350 cm −1 in the spectra of complexes 4 – 6 can be assigned to ν(M─Cl), supporting the coordination of the chloride ions …”

“…The investigated ligand and complexes were separately examined with plates of Gram‐negative and Gram‐positive bacteria and fungi. Antimicrobial tests were conducted using the agar well diffusion method: pathological bacteria, 1 × 10 6 CFU ml −1 ; and fungi, 1 × 10 4 spores ml −1 spread on nutrient agar and Sabouraud dextrose agar, respectively . After the media were solidified by cooling, a 6 mm (in diameter) well was manufactured in solidified agar and loaded with 100 μl of a test specimen solution prepared by dissolving 20 mg of the compound in DMSO.…”

Synthesis, structural characterization and DNA binding affinity of new bioactive nano‐sized transition metal complexes with sulfathiazole azo dye for therapeutic applications

“…This deprives one of the opportunity for computing the crystallite sizes or d ‐spacing inside the lattice giving insight about the solid complexes. The amorphous nature of the compounds reflected the very small size for the aggregates which is easily found within the nanometre range, which can be investigated applying the TEM technique …”

Synthesis, structure, antiproliferative activity and molecular docking of divalent and trivalent metal complexes of 4H‐3,5‐diamino‐1,2,4‐triazole and α‐hydroxynaphthaldehyde Schiff base ligand

“…The UV–visible spectrum of Co(II) complex 2 exhibits one significant band at 16 129 cm −1 assignable to 4 A 2 (F) → 4 T 1 (P) transition characteristic of tetrahedral geometry. The magnetic moment value for complex 2 was calculated to be 4.56 BM which lies in the range suitable for the orbital configuration inside a tetrahedral geometry …”