Synthesis, spectroscopic characterization, thermal stability and biological studies of mixed ligand complexes of gemifloxacin drug and 2,2′-bipyridine with some transition metals

A perception into binary and ternary copper (II) complexes: synthesis, characterization, DFT modeling, antimicrobial activity, protein binding screen, and amino acid interaction

Ensuring healthy lives and promoting well-being for all at all ages is the third goal of the sustainable development plan, so it was necessary to identify the most important problems that threaten health in our world. The World Health Organization declared that antibiotic resistance is one of the uppermost global public health threats facing humanity and searching for new antibiotics is slow. This problem can be approached by improving available drugs to combat various bacterial threats. To circumvent bacterial resistance, three copper(II) complexes based on the pefloxacin drug were prepared and characterized using analytical, spectroscopic, and thermal techniques. The resulting data suggested the formation of one octahedral binary and two distorted square pyramidal ternary complexes. Fluorescence spectra results revealed the formation of a turn-on fluorophore for amino acid detection. Computational calculations investigated quantum and reactivity parameters. Molecular electrostatic potential profiles and noncovalent bond interaction-reduced density gradient analysis indicated the active sites on the complex surface. The complexes were subjected to six microbial species, where the octahedral binary complex provoked its antimicrobial potency in comparison with ternary complexes. The enhanced antimicrobial activity against gram-negative bacterium E-coli compared to gentamicin was exhibited by the three complexes. Docking simulation was performed based on the crystal structure of E. coli and S. pneumoniae receptors using 5I2D and 6O15 codes. The binary complex exhibited a potent fitness score with 5I2D (TBE = - 107 kcal/mol) while ternary complexes displayed the highest docked score of fitness with 6O15.

Robust corrosion guard, mechanical and UV aging properties of metal complex/epoxy hybrid composite coating for C-steel applications

Incorporation of novel-prepared metal–organic complexes as crosslinking accelerators for multifunctional epoxy was on top of interest by coating formulators. The present work investigated the loading of mixed ligand metal complexes (Zr(IV) and Cu(II)) of metformin (MF) and 2.2′bipyridine (Bipy) against the free ligands as crosslinking modifiers via some epoxy coating formulations to assess their superb performances on the C-steel surface. Zr(IV) and Cu(II) demonstrated the minor energy gap (∆E) values at 0.190 au compared to free MF and Bipy according to the calculated energy values, and this behavior reflected their enhanced properties via epoxy coating applications. EIS measurements using high saline formation water as a corrosive medium were performed and offered that PA-DGEBA/MC-Cu coated film showed the superior resistance values (R_ct = 940 and R_c = 930 kΩ cm²). The accelerated corrosion salt spray experiment clarified that PA-DGEBA/MC-Cu coating achieved the least corrosion rate at 0.00049 mm/y and exhibited the highest protection efficiency of 99.84%. SEM/EDX combination survey affirmed the protective performance of the checked coatings. AFM microanalysis confirmed that surface-treated Cu(II) coating displayed the smoothest film surface with complete curing. Mechanical durability properties were evaluated and the obtained results illustrated that pull-off adhesion for PA-DGEBA/MC-Cu coated film fulfilled the highest adhesion strength at 6.3 MPa, the best bend character at 77, and the maximum impact resistance at 59.7 J. UV immovability trial was performed at 10 irradiance and 80 h duration. PA-DGEBA/MC-Cu coated film displayed the highest resistance to UV irradiance with blistering (#8 size and few frequencies) in addition to offering a minor gloss variation and matt properties.

Spectroscopic Characterization, Thermogravimetry and Biological Studies of Ru(III), Pt(IV), Au(III) Complexes with Sulfamethoxazole Drug Ligand

Complexes of Ru(III), Pt(IV), and Au(III) with sulfamethoxazole (SMX) were experimentally produced. The resulted formations of novel metal complexes were discussed using several techniques, such as effective magnetic moment molar conductivity, IR, UV, and 1H NMR spectra, elemental analyses, thermal analysis, microscopic and XRD analyses. The X-ray diffraction patterns of the solid powders of the synthesized sulfamethoxazole complexes indicated their identical formulation. The surface uniformity of the complexes’ samples was confirmed by SEM images. These complexes appear as spots, dark in appearance, with particle sizes of 100–200 nanometers in transmission electron microscopy (TEM) pictures. The sulfamethoxazole ligand was shown to be bidentate coordinated to the metallic ions with sulfonyle oxygen and amido nitrogen groups, according to IR spectral data. Both Ru(III) and Au(III) complexes have an electrolytic nature, but the Pt(IV) complex has non-electrolytic properties. TG and DTG experiments proved the assigned composition and provided information regarding the thermal stability of complexes in a dynamic air atmosphere, according to the thermal analysis. The effect of the novel prepared complexes was examined for antibacterial and antifungal activity in vitro against a variety of pathogens, and they exceeded the sulfamethoxazole ligand in antibacterial activity. It was observed that the Pt(IV) complex has the ultimate activity versus all the assessed organisms relative to all compounds.

Embedding an extraordinary amount of gemifloxacin antibiotic in ZIF-8 framework with one-step synthesis and measurement of its H2O2-sensitive release and potency against infectious bacteria

GEM@ZIF-8 has DLC = 69.82% and DLE = 89.03%, with controlled release dependent on H2O2 concentration, and it shows significant antibacterial activity.

Biochemical Characterization, Phytotoxic Effect and Antimicrobial Activity against Some Phytopathogens of New Gemifloxacin Schiff Base Metal Complexes

String of Fe(III), Cu(II), Zn(II) and Zr(IV) complexes were synthesized with tetradentateamino Schiff base ligand derived by condensation of ethylene diamine with gemifloxacin. The novel Schiff base (4E,4'E)-4,4'-(ethane-1,2-diyldiazanylylidene)bis{7-[(4Z)-3-(aminomethyl)-4-(methoxyimino)pyrrolidin-1-yl]-1-cyclopropyl-6-fluoro-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid} (GMFX-en) and its metal complexes were identified and confirmed by elemental analyses, FT-IR, UV/VIS, ¹ H-NMR spectra, magnetic susceptibility, conductometric measurements and thermal analyses. The FT-IR spectral data showed the chelation behavior of GMFX-en toward the metal ions through oxygen of carboxylate group and nitrogen of azomethine group. In the light of all spectral data, these complexes presumably have octahedral geometry configurations. Thermal analysis specified that the decaying of the metal complexes exist in two or three steps with the final residue metal oxides. Antimicrobial activity of the new prepared metal complexes was screened against some common phytopathogens and their mode of action has been also discussed. The potential phytotoxic effectiveness of the new complexes was furthermore inspected on two commonly experimental plants. The complexes showed significant antimicrobial and phytotoxic effects against the majority of tested phytopathogens and the two tested plants, respectively. The potential antimicrobial activity of the complexes proved their possibility to be used successfully in agropharmacutical industry to control many serious phytopathogens. The phytotoxicity of the studied complexes also indicated their possibility as potential bio-based herbicides alternatives to weed control in crop fields.

Synthesis, spectral, DFT modeling, cytotoxicity and microbial studies of novel Zr(IV), Ce(IV) and U(VI) piroxicam complexes

The Zr(IV), Ce(IV) and U(VI) piroxicam anti-inflammatory drug complexes were prepared and characterized using elemental analyses, conductance, IR, UV-Vis, magnetic moment, ^IHNMR and thermal analysis. The ratio of metal: Pir is found to be 1:2 in all complexes estimated by using molar ratio method. The conductance data reveal that Zr(IV) and U(VI) chelates are non-electrolytes except Ce(IV) complex is electrolyte. Infrared spectroscopic confirm that the Pir behaves as a bidentate ligand co-ordinated to the metal ions via the oxygen and nitrogen atoms of ν(CO)_carbonyl and ν(CN)_pyridyl, respectively. The kinetic parameters of thermogravimetric and its differential, such as activation energy, entropy of activation, enthalpy of activation, and Gibbs free energy evaluated using Coats-Redfern and Horowitz-Metzger equations for Pir and complexes. The geometry of the piroxicam drug in the Free State differs significantly from that in the metal complex. In the time of metal ion-drug bond formation the drug switches-on from the closed structure (equilibrium geometry) to the open one. The antimicrobial tests were assessed towards some types of bacteria and fungi. The in vitro cell cytotoxicity of the complexes in comparison with Pir against colon carcinoma (HCT-116) cell line was measured.