Synthesis, molecular modeling, TD‐DFT, antimicrobial, and in vitro therapeutic activity of new spherical nano‐sized sulfonamide imine ligands and their zinc (II) and copper (II) complexes

Abstract

A series of nanometer-sized spherical sulfonamide imine ligands HL 1-HL 5 and their copper and zinc complexes were synthesized and fully characterized based on elemental analyses, spectroscopic (UV/vis, FT-IR, NMR, EPR, SEM) studies, molar conductance and thermal analyses. Furthermore, computational studies of HL 1-HL 5 were carried out by the DFT/B3LYP method. TD-DFT, HOMO and LUMO energy values, chemical hardness, electronegativity, electrophilic index, softness, and other parameters were calculated. Screening against several pathogenic microorganisms indicated that HL 1 exhibited high activity against the tested Gram-negative bacteria relative to other analogues and the inhibition activity is greater than the standard Gentamicin. Analogously, HL 2 exhibited high potent activity against the tested Gram-positive bacteria. Copper complexes exhibited a higher potent activity than zinc analogues. Noteworthy, inhibition activity of [Cu (L 3)(OAc)] complex is higher than that of the standard Ampicillin. [Cu (L 2)(OAc)] complex displayed a similar activity of the standard bactericides and fungicides in use. The complexes showed appreciated values of MIC against bacterial strains: B. subtilis (MIC = 0.4 μg / mL), E. coli and S. pneumonia (MIC = 1.95 μg / mL) and P. aeruginosa (MIC = 7.81 μg / mL). in vitro cytotoxic activities study proved that [Cu (L 3)(OAc)] complex exhibited appreciable activity versus (HEPG-2); IC 50 = 4.8 μg/ml, while [Cu(L 2)(OAc)] complex showed a high activity against (MCF-7); IC 50 = 6.2 μg/ml. These results could be considered as new findings of promising antitumor candidates for experimental chemotherapy.

Novel metformin complexes: Geometry optimization, non‐isothermal kinetic parameters, DNA binding, on–off light switching and docking studies

“…The energies of HOMO and LUMO as indicated in Table 4 are used to calculate quantum chemical parameters of metal complexes 1 – 3 . [ 40 ] The energy gap between HOMO and LUMO is an important stability indicator. [ 41 ] The lower the value of Eg , the higher is the compound's reactivity.…”

Recent Studies on the Antimicrobial Activity of Copper Complexes

“…The [Cu(L 24 )(OAc)] possessed more potent activity than its parent ligand and it displayed similar activity like the fungicide in use. In this work [34], it was established once again that metal chelates have higher activity than free ligands. 28 and HL 29 ) derived from 2-hydroxy-3-methoxy benzaldehyde and 3-ethoxy-2-hydroxybenzaldeyhde with N,N′-dimethylethane-1,2diamine have been prepared [35].…”

“…The N,O-donor ligands include the salen type ligands studied in a number of works [31][32][33][34]. Three mononuclear copper complexes 17-19 with bis-Schiff base ligands HL 17 -HL 19 were prepared and structurally characterized [31].…”

“…A series of nanometer-sized spherical sulfonamide imine ligands HL 23 -HL 27 and their copper and zinc complexes were synthesized and fully characterized [34]. The composition of copper complexes 23-27 corresponds to the general formula [Cu(L)(OAc)]• nH 2 O.…”

“…Water soluble transition metal (Cu(II), Co(II), Ni(II), and Zn(II)) complexes 34a-34d with N,N,Odonor ligand H 2 L 34 obtained from glycylglycine and 4nitrobenzaldehyde were synthesized [39]. Generally, it has been observed that metal chelates 34a-34d has more antimicrobial activity than the free ligand H 2 L 34 . All the complexes 34a-34d exhibited appreciable antimicrobial activity against the tested microorganisms.…”