1,2,3-triazole derivative: Synthesis,characterization, DFT,molecular docking study and antibacterial-antileishmanial activities

In this study, 4-((1-(4-chlorobenzyl)-1H-1,2,3-triazole-4-yl)methoxy)-3-methoxybenzaldehyde (I) was synthesized and molecular structure of compound I was confirmed by FTIR and NMR (¹H and ¹³C NMR) spectroscopic methods. The geometric structure of compound I was optimized by DFT/B3LYP method using 6–311++G(d, p) basis set. The molecular docking study was carried out against six different proteins. The antibacterial and antileishmanial activities of compound I were tested by microdilution broth with Alamar blue method and minimum inhibitor concentrations (MIC) were determined. According to the test results, it was found to be effective against eleven types of bacteria at different concentrations (MIC: 312–5000 ​μg/mL). In addition, compound I was not effective against leishmania species at the concentrations that were examined.     

Microwave-Assisted One-Pot Synthesis of Bioactive UGI-4CR Using Fluorite as Benign and Heterogeneous Catalyst

Fluorite has been used as an activating heterogeneous catalyst for a rapid and facile one-pot synthesis of biologically active Ugi four-component reaction (Ugi-4CR) under microwave irradiation in good to moderate yields with short reaction times. The catalyst is environmentally benign, commercially available, and reusable several times with no reduction in its efficiency. The resulting Ugi derivatives 5(a–h) were characterized on the basis of ¹H and ¹³C NMR, infrared, elemental analysis, and mass spectral data. The synthesized moieties were screened for their potential antibacterial activities in vitro against a few microorganisms: Staphylococcus aureus (Gram positive), Bacillus subtilis (Gram positive), Escherichia coli (Gram negative), and Proteus vulgaris (Gram negative). The screening data show that compounds 5a, 5c, 5e, and 5h are highly active against the strains.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

d-Xylose-based surfactants: Synthesis,characterization and molecular modeling studies

Pentose-derived surfactants were easily synthesized and fully characterized through classical analytical methods. The interfacial behaviors revealed the importance of both the length of the hydrophobic chain and the nature of the anomeric form. Finally, the spatial conformation of four xylosides was obtained by molecular modeling with software Hyperchem^® 4 using the semi-empirical method PM3, which demonstrated the role of hydrophobic interactions in the stability of the compounds.     

Structural,spectroscopic, molecular docking,thermal and DFT studies on metal complexes of bidentate orthoquinone ligand

4‐Triphenylmethyl‐1,2‐benzoquinone (TPMBQ) reacted with some metal ions and the structure of the new compounds had been identified. The metal to ligand ratio was 1:2 which was revealed by elemental analysis. The complexes were found to have octahedral geometry and their thermal stability was studied using thermogravimetric analysis technique. The molar conductance measurements revealed the electrolytic nature of the synthesized chelates. The IR spectra concluded the bidentate nature of the TPMBQ ligand while the ¹H NMR revealed the presence of water molecules. The XRD spectra of Mn (II) and Fe (III) complexes concluded their crystalline structure while Co (II) and Cu (II) chelates refer to amorphous structures. The geometries of the TPMBQ ligand were optimized using Gaussian 09 W; density functional theory B3LYP method. (DFT)/basis set 6–311++G (d, p). HOMO and LUMO energy values for chelates, chemical hardness and electro‐negativity had been calculated. The ligand and its metal complexes had been examined against different kinds of bacteria such as Proteus vulgaris, Escherichia coli, Staphylococcus aurous and Bacillus subtitles to examine their antimicrobial activity. Molecular docking using Auto Dock tools were utilized.     

Synthesis and characterization of the novel molecular sieve CFSAPO-1

A novel type of molecular sieve named CFSAPO-1 was synthesised hydrothermally in a system of MA(methylamine)-Al₂O₃-P₂O₅-SiO₂-H₂O at 150°C. The molar composition of reactants was: MA: Al₂O₃P₂O₅SiO₂H₂O=(0.8–1.2)1(0.8–1.2)(0.4–3)40. XRD, IR, thermoanalysis, and adsorption studies show that the original product CFSAPO-1 is transformed into a form with molecular sieve properties after calcination. The free dimension of the adsorption window of the form is 5.8–6.2 Å. There were no distinctly thermal effects on the DTA curve at 600°C and 800°C related to two transformations detected by X-ray diffraction.     

Some contribution to W(VI)-peroxo-chemistry: Synthesis,spectroscopic characterization,reactivity and DFT studies

Synthesis of white microcrystalline oxodiperoxotungstate(VI) complexes, K[WO(O₂)₂(L)(H₂O)]·H₂O, (L ?= ?salicylate, 5-chlorosalicylate, 4-hydroxybenzoate) have been achieved from reaction of Na₂WO₄·2H₂O with 30% H₂O₂ and the respective hetero-ligands at pH Ca. 7–7.5 in aqueous medium. The newly synthesized compounds were comprehensively characterized by elemental analyses, spectral studies, room temperature magnetic moment measurements and mass spectrometric studies. Infrared spectra suggest that, peroxo groups are bonded to the WO⁺⁴ center in a triangular bidentate (C_2v) fashion and the hetero-ligands benzene-core hydroxycarboxylic acids viz. salicylic acid, 5-chlorosalicylic acid, 4-hydroxybenzoic acid in anoinic form are coordinated in monodentate manner. Compounds are fairly stable in aqueous solution for sufficient period of time. The results of mass spectrometric analysis lend support to the molecular composition of the complexes ascertained on the basis of elemental analyses and spectroscopic studies. Compound potassium(aquo)(5-chlorosalicylato)oxodiperoxotungstate(VI)monohydrate, K[WO(O₂)₂(5-chlorosalicylate)(H₂O)]·H₂O, act as an oxidant of bromide ion in aqueous phase bromination of chosen organic substrates to their corresponding bromo organics. Density Functional Theory (TD-DFT) calculations were performed on the synthesized complexes substantiated the experimentally obtained results. The TD-DFT optimized structures are in excellent agreement with the results of elemental analyses, spectral as well as mass spectrometric data.     

Novel thiocyanate complexes of cadmium(II) - Synthesis, spectroscopic characterization, X-ray studies and DFT calculations

Three novel thiocyanate cadmium(II) compounds [Cd(ind)₂(SCN)₂]_n (1), [Cd(dpa)Cl(SCN)]_n (2) and [Cd(terpy)(SCN)₂] (3) were synthesized and characterized by spectroscopic and crystallographic methods. Thiocyanate ions of 1 act as bridging ligands generating a one-dimensional chain constructed of Cd(SCN)₂Cd units and expanding along the crystallographic direction [1 0 0]. The Cd(II) ions of 2 are bridged by alternating di-μ-Cl and di-μ_1,3-NCS bridges to one-dimensional chain running along the crystallographic direction [0 1 0]. [Cd(terpy)(SCN)₂] (3) is a square pyramidal mononuclear compound.The fluorescence properties of the complexes 1 and 2 were examined in solid state, whereas fluorescence spectra of 3 were recorded in both solid state and solution. All they were compared with the fluorescence properties of the free ligands. Additionally, the electronic spectrum of 3 were investigated at the TDDFT level employing B3LYP functional in combination with LANL2DZ.     

Crystal structure,spectroscopic characterization,DFT computations and molecular docking study of a synthesized Zn(II) complex

The Zn(II) complex, dichloro[N-hydroxy-1,1-di(2-pyridinyl)methanimine]zinc(II), was synthesized from the reaction between ZnCl₂ and di-2-pyridylketone oxime. The structural and spectral characterizations were performed by using single crystal X-ray diffraction, FT-IR, Laser-Raman, NMR and UV–Vis spectroscopic techniques. To support experimental evidences, computational results were obtained with the DFT/B3LYP method using the 6-311++G(d,p)+LanL2DZ mixed basis set. Theoretical analyses of some structural and spectroscopic results of effects of intermolecular Cl···H interactions in the crystal packing of the Zn(II) complex were investigated with the mentioned computational level. The non-bonding interactions in the experimental crystal packing of the complex were examined by Hirshfeld surface analysis. The HOMO and LUMO analyses were used for investigation of electronic transitions obtained with UV–Vis spectroscopy. NBO analyses were used to investigate the hyperconjugation interactions between donor and acceptor groups, coordination environment, electronic configuration and electron numbers of the Zn(II) metal ion and the natural atomic charges of the complex. The nucleophilic and electrophilic reactive sites of the complex were studied by MEP surface analysis. The static polarizabilities (α) and static hyperpolarizabilities (β) were analyzed theoretically to characterize NLO profile of the complex. The interaction with A-DNA (PDB ID: 1ZF6) of the Zn(II) complex was investigated with a molecular docking study.     

A novel tricarbonyl rhenium complex of 2-benzoylpyridine - Synthesis, spectroscopic characterization, X-ray structure and DFT calculations

The reaction of Re(CO)₅Cl with 2-benzoylpyridine (bopy) has been examined and a novel Re(CO)₃⁺ tricarbonyl - fac-[Re(CO)₃(bopy)Cl] - has been obtained. The compound has been studied by IR, UV-Vis spectroscopy and X-ray crystallography. The molecular orbital diagram of the tricarbonyl has been calculated with the density functional theory (DFT) method. The spin-allowed singlet-singlet electronic transitions of [Re(CO)₃(bopy)Cl] have been calculated with the time-dependent DFT method, and the UV-Vis spectrum of the title compound has been discussed on this basis.     

Synthesis and antimicrobial activity of quinoline-based 2-pyrazolines

A series of 2-pyrazolines was prepared in a reaction of quinolinylchalcones with phenyl hydrazine under both conventional and microwave-induced heating. Structures of the synthesized compounds were characterized by spectroscopic data and CHN analyses. All prepared compounds were tested for antimicrobial activity against bacterial strains, viz. Staphylococcus aureus, Salmonella typhii, Escherichia coli, and Shigella dysentery. Almost all synthesized compounds have shown antimicrobial activity; however, compounds with a chloro group as a substituent have been found to be more effective.     

Exhaustive search of the configurational space of heat-shock protein 90 with its inhibitor by multicanonical molecular dynamics based dynamic docking

Multicanonical molecular dynamics based dynamic docking was used to exhaustively search the configurational space of an inhibitor binding to the N-terminal domain of heat-shock protein 90 (Hsp90). The obtained structures at 300 K cover a wide structural ensemble, with the top two clusters ranked by their free energy coinciding with the native binding site. The representative structure of the most stable cluster reproduced the experimental binding configuration, but an interesting conformational change in Hsp90 could be observed. The combined effects of solvation and ligand binding shift the equilibrium from a preferred loop-in conformation in the unbound state to an α-helical one in the bound state for the flexible lid region of Hsp90. Thus, our dynamic docking method is effective at predicting the native binding site while exhaustively sampling a wide configurational space, modulating the protein structure upon binding.     

Synthesis, spectroscopic characterization, X-ray structure, and DFT calculations of [Cu(tppz)(SCN)2]

This article presents a combined experimental and computational study of [Cu(tppz)(SCN)₂], where ttpz stands for 2,3,5,6-tetra-(2-pyridyl)pyrazine. The compound has been studied by IR, UV–Vis spectroscopy, and single crystal X-ray analysis. The geometry around copper atom may be described as a distorted square pyramid. The equatorial plane is defined by three nitrogen atoms of tppz and one nitrogen atom of thiocyanate group. The apical site is occupied by nitrogen atom of the second SCN^? ion. The electronic spectrum of [Cu(tppz)(SCN)₂] was analyzed, and bands were assigned through the DFT/TDDFT procedures.     

Synthesis,characterization, anticancer activity,and molecular docking of some new sugar hydrazone and arylidene derivatives

New sugar hydrazone moieties, their oxadiazoline derivatives, and arylidene analogues were prepared and chemically elucidated using spectroscopic analysis, such as nuclear magnetic resonance, for hydrogen ¹HNMR, carbon ¹³CNMR, elemental analysis, and Infrared (IR). The prepared compounds were purified and tested against breast cancer cells (MCF-7). Compounds 4c, 4d, 6b, and 6d exhibited moderate to very high anti-breast cancer activity, with a percentage of inhibition of 96.19%, 93.08%, 74.33%, and 86.05% respectively; the reference 5-fluorouracil had an inhibitory percentage of 96.02%.     

Synthesis, structural characterization, and fluorescent chemosensory properties of novel molecular clips based on diethoxycarbonyl glycoluril

A pair of novel fluorescent molecular clips was synthesized from diethoxycarbonal glycoluril cyclic ether and 1,2-dihydro-indazol-3-one. Their structures and conformations were confirmed by single crystal X-ray diffraction and chemosensory properties were studied by fluorescent spectroscope. Both of them exhibited selective recognition toward Fe³⁺ over other metal ions examined in DMF/CH₃OH (50:1, v/v).     

Synthesis, spectroscopic characterization, DFT studies and biological assays of a novel gold(I) complex with 2-mercaptothiazoline

A new gold(I) complex with 2-mercaptothiazoline (MTZ) with the coordination formula [AuCN(C₃H₅NS₂)] was synthesized and characterized by chemical and spectroscopic measurements, DFT studies and biological assays. Infrared (IR) and ¹H, ¹³C and ¹⁵N nuclear magnetic resonance (NMR) spectroscopic measurements indicate coordination of the ligand to gold(I) through the nitrogen atom. Studies based on DFT confirmed nitrogen coordination to gold(I) as a minimum of the potential energy surface with calculations of the hessians showing no imaginary frequencies. Thermal decomposition starts at temperatures near 160 °C, leading to the formation of Au⁰ as the final residue at 1000 °C. The gold(I) complex with 2-mercaptothiazoline (Au-MTZ) is soluble in dimethyl sulfoxide (DMSO), and is insoluble in water, methanol, ethanol, acetonitrile and hexane. The antibacterial activities of the Au-MTZ complex were evaluated by an antibiogram assay using the disc diffusion method. The compound showed an effective antibacterial activity against Staphylococcus aureus (Gram-positive) and Escherichia coli and Pseudomonas aeruginosa (Gram-negative) bacterial cells. Biological analysis for evaluation of the cytotoxic effect of the Au-MTZ complex was performed using HeLa cells derived from human cervical adenocarcinoma. The complex presented a potent cytotoxic activity, inducing 85% of cell death at a concentration of 2.0 μmol L⁻¹.     

Synthesis, spectroscopic characterization, X-ray structure and DFT calculations of [ReOCl2(8-Sqn)(OPPh3)]

The reaction of [ReOCl₃(PPh₃)₂] with 8-quinolinethiol (8-HSqn) has been examined, and the [ReOCl₂(8-Sqn)(OPPh₃)] complex has been obtained. It was characterized by IR, UV–Vis spectroscopy and single crystal X-ray analysis. The nature of the frontier orbitals and the electronic transitions involved in the absorption spectrum have been studied by means of the density functional and time-dependent density functional methods.