Nano structure zinc (II) Schiff base complexes of a N3-tridentate ligand as new biological active agents: spectral, thermal behaviors and crystal structure of zinc azide complex

In vitro α-glucosidase, docking and density functional theory studies on novel azide metal complexes

Aim: The goal of this study is to synthesize new metal complexes containing N-methyl-1-(pyridin-2-yl)methanimine and azide ligands as α-glucosidase inhibitors for Type 2 diabetes. Materials & methods: The target complexes (12-16) were synthesized by reacting N-methyl-1-(pyridin-2-yl)methanimine (L1) with sodium azide in the presence of corresponding metal salts. The investigation of target protein interactions, vibrational, electronic and nonlinear optical properties for these complexes was performed by molecular docking and density functional theory studies. Results: Among these complexes, complex 13 (IC50 = 0.2802 ± 0.62 μM) containing Hg ion showed the highest α-glucosidase inhibitory property. On the other hand, significant results were detected for complexes containing Cu and Ag ions. Conclusion: Complex 13 may be an alternate anti-diabetic inhibitor according to in vitro/docking results.

Synthesis, spectral characterization, DFT calculations, pharmacological studies, CT-DNA binding and molecular docking of potential N, O-multidentate chelating ligand and its VO(II), Zn(II) and ZrO(II) chelates

The pharmacological efficacy of the variety tetradentate ligands encouraged us to design attractive compounds through effective synthetic procedure. The prepared Schiff base ligand 6,6'-((1E,1'E)-((4-chloro-1,2-phenylene)bis(azaneylylidene))bis(methaneylylidene))bis(2-ethoxy phenol (H₂L), which derived from 4-chloro-o-phenylenediamine and 3-ethoxy-salicylaldehyde and its VO(II), Zn(II) and ZrO(II) metal chelates, have been synthesized and characterized with aim of that it may struggle the invasion of drug resistance. The chemical structural of studied compounds were discussed by TGA, elemental analysis, UV-Vis., ¹H NMR, ¹³C NMR, FTIR, mass spectral, PXRD, molar conductance, magnetic susceptibility measurements and density functional theory. The results assigned square pyramid geometries for [VOL] and [ZrOL].2H₂O chelates and an octahedral geometry for [ZnL(H₂O)₂].2H₂O chelate. Powder XRD data showed that the complexes are monoclinic with polycrystalline nature. The results of CT-DNA interaction with the titled chelates showed that the binding between CT-DNA and the metal complexes occurs through intercalation mode. Their CT-DNA binding efficiency estimated in terms of their binding constants (K_b), which gave the order: VOL (6.9 × 10⁵) > ZrOL (6.3 × 10⁵) > ZnL(H₂O)₂ (5.5 × 10⁵). The antimicrobial activities of the synthesized compounds were tested against selected fungal and bacterial strains using well diffusion technique. The obtained chelates showed higher antifungal and antibacterial activities than their corresponding ligand. Furthermore, the M-complexes showed higher potent cytotoxic effect toward HEK-293, human colorectal HepG-2, HCT-116 and MCF-7 adenocarcinoma cell lines compared to the free H₂L ligand. Investigation of antioxidant property represented that all the prepared complexes have better radical scavenging potencies against DPPH radicals than the free H₂L ligand. To study the molecular docking of proposed compounds versus Tyrosine kinases receptor (TKR), we used AutoDock1.5.6rc3® suite. The current compounds (H₂L, VOL, ZrOL and ZnL(H₂O)₂) and STI were found to bind with C-kit of TKR with HBs at ILE789.A, ILE808.A, ASP810.A, GLU640.A and TYR846 amino acid residue and the binding energies were - 8.9, -8.93, -8.83, -1.48 and -10.39 kcal/mol respectively.

Some new nanostructure zinc complex: Synthesis, spectral analyses, crystal structure, Hirshfeld surface analyses, antimicrobial/anticancer, thermal behavior and usage as precursor for ZnO nanostructure

In this work, a new tridentate ligand, its some novel zinc halide/pseudohalide complexes and their antimicrobial and cytotoxic effects of them are described. Characterization data of these compounds have been achieved via several physical and micro analytical techniques. As typical one, X-ray crystal structure analysis of zinc azide complex was run showing zinc center is penta-coordinated by three nitrogen atoms from Schiff base ligand and two terminal azide nitrogen atoms as a distorted square pyramidal geometry. Hirshfeld surfaces analysis clears the important role of interactions related to azide groups (NH⋯N and CH⋯N hydrogen bonds) in the stabilization of its supramolecular structure. According to data obtained from thermal analysis (TG/DTG/DTA), all complexes are decomposed at four or more thermal stages below 1000 °C. Moreover antimicrobial activities of the compounds were screened against some gram positive and gram negative bacteria. Furthermore anticancer activities of the complexes were studied against MDA-MB468 and k562 as two cancer cell lines. In final, three zinc complexes were also synthesized in nano scale by sonochemical method and one of them was utilized as the precursor for preparation of nanostructure ZnO confirmed by XRD pattern and SEM image.

Sonochemical synthesis and characterization of new seven coordinated zinc, cadmium and mercury nitrate complexes: New precursors for nanostructure metal oxides

The nitrate complexes of group 12 elements with a tridentate Schiff base ligand (L = (E)-N1-((E)-3- phenylallylidene)-N2-(2-((E)-((E)-3-phenylallylidene) amino)ethyl) ethane-1,2-diamine) were synthesized via sonochemical process and characterized by various physical and chemical methods. The structural analysis of the zinc nitrate complex by single crystal X-ray diffraction analysis shows that the central atom is seven-coordinated by three nitrogen atoms from the Schiff base ligand as well as four oxygen atoms from two different nitrate anions. The geometry around the metal center can be described as a distorted pentagonal bipyramid. The crystal packing analysis of zinc nitrate complex indicates that the intermolecular interactions related to nitrate groups plays the essential role in the orientation of supramolecular structure. Hirshfeld surfaces (HS) and their corresponding fingerprint plots (FP) have been also used for further investigation of crystal structure of zinc nitrate complex. Furthermore thermal analyses (TG/DTG) of three nanostructure complexes were carried out and discussed. Finally, direct thermolysis of zinc and cadmium nitrate complexes in air atmosphere led to the production of zinc and cadmium oxide nanoparticles.

Antibacterial Activities of Azole Complexes Combined with Silver Nanoparticles

Growing antimicrobial resistance is considered a potential threat for human health security by health organizations, such as the WHO, CDC and FDA, pointing to MRSA as an example. New antibacterial drugs and complex derivatives are needed to combat the development of bacterial resistance. Six new copper and cobalt complexes of azole derivatives were synthesized and isolated as air-stable solids and characterized by melting point analyses, elemental analyses, thermogravimetric analyses (TGA), and infrared and ultraviolet/visible spectroscopy. The analyses and spectral data showed that the complexes had 1:1 (M:L) stoichiometries and tetrahedral geometries, the latter being supported by DFT calculations. The antibacterial activities of the metal complexes by themselves and combined with silver nanoparticles (AgNPs; 2 μg mL^-1) were assessed in vitro by broth microdilution assays against eight bacterial strains of clinical relevance. The results showed that the complexes alone exhibited moderate antibacterial activities. However, when the metal complexes were combined with AgNPs, their antibacterial activities increased (up to 10-fold in the case of complex 5), while human cell viabilities were maintained. The minimum inhibitory concentration (MIC₅₀) values were in the range of 25-500 μg mL^-1. This study thus presents novel approaches for the design of materials for fighting bacterial resistance. The use of azole complexes combined with AgNPs provides a new alternative against bacterial infections, especially when current treatments are associated with the rapid development of antibiotic resistance.

Acute Toxicity and Gastroprotection Studies of a New Schiff Base Derived Manganese (II) Complex against HCl/Ethanol-Induced Gastric Ulcerations in Rats

Manganese is a crucial element for health. In this study, the gastroprotective efficacy of Mn (II) complex (MDLA) against acidified ethanol (HCl/Ethanol)-induced gastric ulceration in rats was evaluated. The animals were distributed into 5 groups. Groups 1 and 2 received carboxymethylcellulose (CMC), group 3 was pretreated with omeprazole, and groups 4 and 5 were given 10 and 20 mg/kg of MDLA, respectively. After one hour, CMC and HCl/Ethanol were given to groups 2–5 whilst the animals in group 1 were ingested with CMC. After sacrifice, gastric lesions were evaluated by wall mucus, gross appearance, histology, antioxidant enzymes and immunohistochemistry. Group 2 displayed severe gastric damage with a significant reduction in wall mucus. Conversely, gastric lesions were reduced in groups 3–5 by 85.72%, 56.51% and 65.93%, respectively. The rats in groups 3–5 showed up-regulation of heat shock protein 70 (Hsp70) with down-regulation of Bcl-2-associated protein x (Bax). Pretreatment with omeprazole or MDLA led to an increase in the uptake of Periodic Acid Schiff (PAS) stain in the glandular part of the gastric tissue, raised levels of prostaglandin E2 (PGE₂) and superoxide dismutase (SOD), and a reduction in malondialdehyde (MDA) concentrations. These results suggested the gastroprotective action of Mn (II) complex.

Synthesis, X-ray crystal structures and thermal analyses of some new antimicrobial zinc complexes: New configurations and nano-size structures

Some new five coordinated ZnLX2 complexes, where L is N3-Schiff base ligand obtained by condensation reaction between diethylenetriamine and (E)-3-(2-nitrophenyl)acrylaldehyde and X (Cl(-), Br(-), I(-), N3(-) and NCS(-)), were synthesized and characterized by FT-IR, (1)H and (13)CNMR, UV-visible, ESI-mass spectra and molar conductivity measurements. The structures of zinc iodide and thiocyanate complexes were determined by X-ray crystallographic analysis. The X-ray results showed that the Zn (II) center in these complexes is five-coordinated in a distorted trigonal-bipyramidal configuration. Zinc iodide and thiocyanate complexes crystallize in the monoclinic and triclinic systems with space groups of C2/c and P1- with eight and two molecules per unit cell respectively. The crystal packing of the complexes consists of intermolecular interactions such as C-H(…)O and C-H(…)I, C-H(···)S, N(…)O, together with π-π stacking and some other unexpected interactions. The mentioned interactions cause three-dimensional supramolecular structure in the solid state. Zinc complexes were also prepared in nano-structure by sonochemical method confirmed by XRD, SEM and TEM analyses. Moreover, ZnO nanoparticles were synthesized by direct thermolysis of zinc iodide complex. Furthermore, antimicrobial and thermal properties of the compounds were completely investigated.

Structural and computational study of some new nano-structured Hg(ii) compounds: a combined X-ray, Hirshfeld surface and NBO analyses

Crystal structure, Hirshfeld surface, DFT and NBO analyses of two new distorted square-pyramidal mercury complexes are presented.