Our prior studies have illustrated that the uracil ruthenium(II) diimino complex, [Ru(Hucp)Cl(PPh)] (1) (Hucp = 2,6-bis-((6-amino-1,3-dimethyluracilimino)methylene)pyridine) displayed high hypoglycemic effects in diet-induced diabetic rats. To rationalize the anti-diabetic effects of 1, three new derivatives have been prepared, cis-[Ru(bpy)(urdp)]Cl (2) (urdp = 2,6-bis-((uracilimino)methylene)pyridine), trans-[RuCl(PPh)(urdp)] (3), and cis-[Ru(bpy)(Hucp)](PF) (4). Various physicochemical techniques were utilized to characterize the structures of the novel ruthenium compounds.
View Article and Find Full Text PDFUnlabelled: The new compound 4-hydroxy-1-[(4-nitrophenyl)sulfonyl]pyrrolidine-2-carboxyllic acid was obtained by the reaction of 4-hydroxyproline with 4-nitrobenzenesulfonyl chloride. The compound was characterized using single crystal X-ray diffraction studies. Spectroscopic methods including NMR, FTIR, ES-MS, and UV were employed for further structural analysis of the synthesized compound.
View Article and Find Full Text PDFIn this study, we used computational methods to investigate the interaction of amphetamine (AMP) with 1,2-indanedione (IND) and 1,8-diazafluoren-9-one (DFO) so as to understand whether AMP can be detected in latent fingerprints using either of these reagents. The results show that the binding energies of AMP with IND and DFO were enhanced by the presence of amino acid from -9.29 to -12.
View Article and Find Full Text PDFThe thermodynamics and mechanisms of the atmospherically relevant reaction dimethyl sulphide (DMS) + atomic chlorine (Cl) were investigated in the absence and presence of a single water molecule, using electronic structure methods. Stationary points on each reaction surface were located using density functional theory (DFT) with the M06-2X functional with aug-cc-pVDZ (aVDZ) and aug-cc-pVTZ (aVTZ) basis sets. Then fixed point calculations were carried out using the UM06-2X/aVTZ optimised stationary point geometries, with aug-cc-pVnZ basis sets (n = T and Q), using the coupled cluster method [CCSD(T)], as well as the domain-based local pair natural orbitals coupled cluster [DLPNO-UCCSD(T)] approach.
View Article and Find Full Text PDFSynthesis of sulfonamide through an indirect method that avoids contamination of the product with no need for purification has been carried out using the indirect process. Here, we report the synthesis of a novel sulfonamide compound, ({4-nitrophenyl}sulfonyl)tryptophan (DNSPA) from 4-nitrobenzenesulphonylchloride and L-tryptophan precursors. The slow evaporation method was used to form single crystals of the named compound from methanolic solution.
View Article and Find Full Text PDFThe role of cyclopropane substitution on the ethylene in [3+2] cycloaddition (32CA) reactions of cyclic nitrones has been studied within Molecular Electron Density Theory (MEDT) at the B97X-D/6-311G(d,p) computational level. Electron Localization Function (ELF) analysis of the ethylenes shows that the presence the cyclopropane only slightly increases the electron density in the C-C bonding region. Analysis of the Conceptual DFT reactivity indices indicates that the presence of the cyclopropane does not produce any remarkable change in the reactivity of these strained ethylenes.
View Article and Find Full Text PDFWe present the results of the analysis of 2,2,6,6-tetramethyl-4-oxo-piperidinium nitrate isolated from the stem bark of a tree growing in Nigeria. The low-temperature molecular structure comprises one 2,2,6,6-tetramethyl-4-oxopiperidinium cation and one nitrate anion as one molecule in the asymmetric unit. The compound crystallizes in the monoclinic space group 2/.
View Article and Find Full Text PDFThe coating industry is one of the most important consumers of water and chemicals and consequently is a major water polluter in Mauritius. The focus of this study was to characterise wastewater generated by a coating industry in Mauritius. The objectives were to develop a wastewater sampling strategy and to analyse the pollutant parameters as per Mauritian regulations.
View Article and Find Full Text PDFJ Comput Chem
May 2022
We investigated the flow of electron density along the cyclocondensation reaction between ethyl acetate 2-oxo-2-(4-oxo-4H-pyrido[1.2-a]pyrimidin-3-yl) polyazaheterocycle (1) and ethylenediamine (2) at the ωB97XD/6-311++G(d,p)computational method within of bond evolution theory (BET). The exploration of potential energy surface shows that this reaction has three channels (1-3) with the formation of product 3 via channel-2 (the most favorable one) as the main product and this is in good agreement with experimental observations.
View Article and Find Full Text PDFUnlabelled: Hydroxychloroquine (HCQ) and favipiravir (FPV) are known to be effective antivirals, and there are reports about their use to fight the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) despite that these are not conclusive. The use of combined drugs is common in drug discovery, and thus, we investigated HCQ and FPV as a combined drug. The density functional theory method was used for the optimization of geometries, spectroscopic analysis and calculation of reactivity parameters.
View Article and Find Full Text PDFThe proverb "Old is gold" is applicable in drug discovery and the proverb "All that Glitters is not Gold" is also appropriate. In the COVID-19 era, there has been a race for drugs to be effective against SARS-CoV-2. There are reports about the uses of Remdesivir and Favipiravir as existing antivirals against virus but none have been conclusive so far.
View Article and Find Full Text PDFNat Prod Res
June 2022
The current research used a virtual screening method to study 57 isolated phytochemicals (alkaloids, phytosterols, and flavonoids) against the SARS-CoV-2 main protease (M). The absorption, distribution, metabolism, excretion, and toxicity (ADMET) of the selected compounds were analysed using admetSAR tool while SwissADME and Molinspiration chemoinformatics tools were used to examine the oral bioavailability and drug-likeness properties. Parameters such as physicochemical properties, activity spectra for substances (PASS) prediction, bioactivity, binding mode, and molecular interactions were also analysed.
View Article and Find Full Text PDFPurpose: Diabetes mellitus is a common condition in the clinically obese. Bariatric surgery is one of the ways to put type 2 diabetes in remission. Recent findings propose the appetite-regulator peptide tyrosine tyrosine (PYY) as a therapeutic option for patients with type 2 diabetes.
View Article and Find Full Text PDFA-234, [EtO-P([double bond, length as m-dash]O)(F)-N[double bond, length as m-dash]C(Me)-N(Et)], is the suspected A-type nerve agent used in the Skripal attack on the 4th of March 2018. Studies related to the structure and reactivity of this compound are limited. We, therefore, aimed at understanding the underlying hydrolysis mechanism of A-234 within the DFT framework.
View Article and Find Full Text PDFA microhydration study of sulfur mustard (SM) was carried out using M06-2X, B3LYP, B3LYP-D3, and MP2 levels of theory with the 6-311++G(2d,2p) basis set. The changes in energetics, structural parameters and vibrational wavenumbers following the addition of up to three discrete water molecules to SM were analyzed. We observed slight changes in the geometry of SM upon microhydration.
View Article and Find Full Text PDFCorrection for 'A colorimetric probe for the real-time naked eye detection of cyanide and hydroxide ions in tap water: experimental and theoretical studies' by Veikko Uahengo et al., Analyst, 2019, 144, 6422-6431.
View Article and Find Full Text PDFWe have computationally studied the bimolecular nucleophilic substitution (S 2) reactions of M NH + CH Cl (M = Li , Na , K , and MgCl ; n = 0, 1) in the gas phase and in tetrahydrofuran solution at OLYP/6-31++G(d,p) using polarizable continuum model implicit solvation. We wish to explore and understand the effect of the metal counterion M and of solvation on the reaction profile and the stereochemical preference, that is, backside (S 2-b) versus frontside attack (S 2-f). The results were compared to the corresponding ion-pair S 2 reactions involving F and OH nucleophiles.
View Article and Find Full Text PDFAntimicrobial agents containing symmetrical triiodides complexes with halogen bonding may release free iodine molecules in a controlled manner. This happens due to interactions with the plasma membrane of microorganisms which lead to changes in the structure of the triiodide anion. To verify this hypothesis, the triiodide complex [Na(12-crown-4)]I was prepared by an optimized one-pot synthesis and tested against 18 clinical isolates, 10 reference strains of pathogens and five antibiotics.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
February 2020
A new photoredox-catalyzed decarboxylative radical addition approach to functionalized cyclobutanes is described. The reaction involves an unprecedented formal Giese-type addition of C(sp )-centered radicals to highly strained bicyclo[1.1.
View Article and Find Full Text PDFHerein, a colorimetric sensor (L) based on a naphthyl derivative bearing hydrazone receptors was synthesized via a one-step reaction process, and its recognition properties towards biologically important anions in an acetonitrile-water mixture were investigated by naked-eye observation and UV-Vis and H NMR spectroscopy. The molar addition of anions, such as TBAF, TBAOH, TBACN and TBAAcO, induced a significant red shift in the charge transfer band (Δλ = 73 nm, from 337 nm to 410 nm), in agreement with visible "naked eye" detectable colorimetric activities; in addition, soaked-in-L paper strips were prepared, which could significantly discriminate cyanide (KCN) and hydroxide (NaOH) ions dissolved in tap water via the litmus test method. This study was complemented by density functional theory computations to gain more insight into the interaction between L and anions.
View Article and Find Full Text PDFNovichoks are the suspected nerve agents in the March 2018 Skripal poisoning. In this context, the novichok agent A234 (chemical structure proposed by Mirzayanov) was studied using computational methods to shed light on its molecular, electronic, spectroscopic, thermodynamic and toxicity parameters as well as on potential thermal and hydrolysis degradation pathways. The poisoning action and antidote of A234 were also investigated.
View Article and Find Full Text PDFComparative study of nonlinear optical properties of red fluorescent coumarins was carried out with density functional theory based ab initio method using the popular global hybrid (GH) and range separated hybrid (RSH) functionals and correlated with the spectroscopic values. The GHs - M06 L, PBE1PBE, M06, BHHLYP, M062X and M06HF and RSHs - HISSbPBE, wB97, wB97X, HSEH1PBE, CAM-B3LYP and wB97XD in combination with the double zeta basis function 6-311 + G(d,p) were used. The computed polarizability (α), hyperpolarizability of the first order (β) and second order (γ) computed by the RSHs are closer to the spectroscopic values compared to GHs.
View Article and Find Full Text PDFThe distortion/interaction-activation strain model (D/I-ASM), a fragment analysis method, is applied to study the structure-reactivity relationship in reactions. The application of D/I-ASM involves the generation of input files for points along a reaction profile, submission of input files to a quantum software package, processing of parameters from the resulting output files and generation of graphical plots. The ExcelAutomat tool (Laloo et al.
View Article and Find Full Text PDFA Molecular Electron Density Theory (MEDT) study of the regio- and stereoselectivity of the [3 + 2] cycloaddition (32CA) reaction of 1-phosphorinium-3-olate and 1-methylphosphorinium-3-olate with methyl methacrylate was carried out using the B3LYP/6-31G(d) method. In order to test the method dependence for the most favorable reaction path leading to the 1-substituted 6- cycloadduct (CA) various functionals using higher basis sets were taken into consideration in the gas phase. An analysis of the energetic parameters indicates that the reaction path leading to 6- CA are kinetically as well as thermodynamically favored in the gas phase, THF and ethanol.
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