Novel metal complexes with pyrano[3,2‐c]quinoline‐3‐carboxaldehyde: Synthesis, spectroscopic, molecular modeling, QSAR, antimicrobial, and antitumor studies

Abstract

Reaction of 6‐ethyl‐4‐hydroxy‐2,5‐dioxo‐5,6‐dihydro‐2H‐pyrano[3,2‐c]quinoline‐3‐carboxaldehyde (HL) with some metal ions, namely, manganese (II), cobalt (II), nickel (II), zinc (II), cadmium (II), chromium (III), iron (III), cerium (III), oxovanadium (IV), and dioxouranium (VI), yielded a new series of metal complexes; with the general formula, [MHnLAm(H2O)x]Xy·zH2O, n = 0–1, A = NO3− or OAc−, m = 0–2, X = NO3− or SO42−, y = 0–1, and z = 0–3. The metal complexes were characterized by elemental analysis, molar conductance, magnetic moment, thermal analysis, and spectroscopic studies. The HL ligand coordinated with metal ions as monobasic or neutral bidentate via OO donor sites of aldehyde –O and phenolic –OH producing metal complexes with tetrahedral, octahedral, and pentagonal bipyramidal geometries. On the bases of PM3 level, molecular orbital calculations were performed for metal complexes using HyperChem 7.52 program, and the results were correlated with the experimental data. The biological activity of chelating agent and its metal complexes was screened towards Staphylococcus aureus and Bacillus subtilis as Gram‐positive bacteria; Salmonella typhimurium and Escherichia coli as Gram‐negative bacteria, as well as Candida albicans (yeast) and Aspergillus fumigatus (fungus). The antitumor activity of the HL ligand and its metal complexes was tested against Ehrlich Ascites Carcinoma cell line (EAC), which revealed promising IC50 values, comparable with that of cisplatin. Additional QSAR models were developed to predict the biodistribution of a smaller set of metal complexes and the calculated data correlated with antitumor results.

Novel NO2 semicarbazone ligand and its metal complexes as VEGFR‐2 inhibitors: Synthesis, spectral characterization, density functional theory calculations, molecular docking, and antimicrobial and antitumor evaluation

“…The 1 H NMR spectrum of 6‐ethyl‐4‐hydroxy‐2,5‐dioxo‐5,6‐dihydro‐2 H ‐pyrano[3,2‐ c ]quinoline‐3‐carboxaldehyde was previously reported in our earlier research. [ 25 ] The 1 H NMR spectrum of the prepared ligand ( H 2 L ) (Figure 2, Table 3) showed the disappearance of the aldehydic proton, which was observed at δ 10.03 ppm in the 1 H NMR spectrum of the carboxaldehyde. A new signal attributed to the azomethine (CHN) proton appeared at δ 8.22 ppm; also, the spectrum showed D 2 O exchangeable signals assignable to NH 2 , NH, and OH at δ 6.73, 9.41, and 12.39 ppm, respectively.…”

“…Pyrano[3,2‐ c ]quinoline‐3‐carboxaldehyde derivative (2.85 g, 0.01 mol) that was synthesized according to a method described elsewhere [ 25 ] was dissolved in hot absolute ethanol (40 ml); after that, semicarbazide hydrochloride (1.12 g, 0.01 mol) dissolved in water (5 ml) was added. Then, the reaction mixture was heated under reflux for 30 min.…”

“…[23] So, the newly synthesized ligand and its complexes were exposed to molecular docking studies, to predict and conclude the most candidates with a strong binding propensity to VEGFR-2 proteins. [24] Due to our interest in compounds based on pyrano [3,2-c]quinoline-3-carboxaldehyde, [25,26] the present work aims to synthesize a new semicarbazone ligand, H 2 L, by condensation of pyrano [3,2-c]quinoline-3-carboxaldehyde with semicarbazide hydrochloride. The H 2 L ligand reacted with various metal ions that are Cu(II), Ni(II), Co(II), Fe(III), Cr(III), and Mn(II) in the molar ratio 1:1.…”

NiIIand CoIIbinary and ternary complexes of 3-formylchromone: spectroscopic characterization, antimicrobial activities, docking and modeling studies

“…According to Hansch and Leo, highly lipophilic compounds will participate in the lipid interior of membranes and be retained there. A drug has low solubility with a higher log P and has difficulty penetrating lipid membranes with a lower log P. 48 Lipophilicity (log P) is a feature that affects absorption, solubility, distribution, excretion qualities, metabolism, and pharmacological activity; normalized B.S. and normalized C.A.…”

New mixed‐ligand thioether‐quinoline complexes of nickel(II), cobalt(II), and copper(II): Synthesis, structural elucidation, density functional theory, antimicrobial activity, and molecular docking exploration

“…These compounds are also widely utilized in medicine, where they have shown effective as anticancer agents, antibacterial agents, antiseptics, and antineoplastics. 29 A literature survey indicated that complexes of Co(II), Ni(II), and Cu(II) with single azo or 8-hydroxyquinoline (HQ) ligand were reported to show anticancer, 30,31 antitumor, 32,33 antioxidant, 34,35 and antimicrobial activity. 36,37 Also, previous studies indicated that Co(II), Ni(II), and Cu(II) complexes based on azo-8-hydroxyquinoline derivatives exhibited good to moderate affinity to dyeing polyester fabrics 38 and promising antimicrobial activities.…”