Vol 89, No 5 (2019)

Four complexes [Ni(DMA)₂(H₂O)₄]Cl₂·2H₂O, [Ni(DMF)₂(H₂O)4]Cl2·₂H₂O, and [Ni(DMA)₆][NiCl₄], [Ni(DMF)₂(H₂O)₂Cl₂] were isolated from ternary water-organic saline systems containing nickel chloride and N, N-dimethylacetamide-water and N, N-dimethylformamide-water binary solvents. The obtained complexes were studied by X-ray structural analysis. The formation of hydrogen bonds between water molecules of the nickel ion solvate sphere, chloride ions, and non-coordinated water molecules located in the cavity of the crystal structure was detected.

A series of 2-(indol-3-yl)-1-nitroethenes containing an ester, acetyl, benzoyl, or cyano group in the geminal position with respect to the nitro group have been synthesized, and their structure has been studied by ¹H, ¹³C−{¹H} NMR, IR, and UV spectroscopy.

The reaction of acetylenic ketones with cyanothioacetamide in the presence of morpholine yields 4,6-disubstituted 2-thioxo-1,2-dihydropyridine-3-carbonitriles. Structure of the obtained compounds was proved using 2D NMR spectroscopy, as well as transformations into 3-aminothieno[2,3-b]pyridine-2-carboxamide derivatives.

3-Allyl-6-methyl-2-thiouracil reacts with iodine to form 2-iodomethyl-7-methyl-5-oxo-3,5-dihydro-2H-thiazolo-[3,2-a]pyrirmdinium iodide. The reaction with bromine leads to the formation of a mixture of 2-bromomethyl-7-methyl-5-oxo-3,5-dihydro-2H-thiazolo[3,2-a]pyrimidinium and 6-bromo-2-bromomethyl-7-memyl-5-oxo-3,5-dihydro-2H-thiazolo[3,2-a]pyrimidinium bromides.

Esters of individual natural carotenoids lutein and astaxanthin with benzoic, 4-methylbenzoic, nicotinic, and mandelic acids have been synthesized. The esterification reaction of carotenoids has been carried out in an anhydrous medium at 37°C using of Novozyme 435 biocatalyst. The in silico prediction of the products activity by means of molecular docking has identified two compounds promising regarding the action towards the retinal protein Stard3 PDP code 5I9J.

O-Silylurethanes have been synthesized in up to 87% yield via the reaction of tin tetracarbamates with organyl chlorosilanes in the presence of tertiary amines.

Regioselective mono- and diphosphorylation of 1,4:3,6-dianhydro-d-sorbitol containing two hydroxyl groups differing in steric availability has been studied. The nature of the amine acting as activator and acceptor of hydrogen chloride have had significant impact on the direction of phosphorylation and the structure of the resulting products.

The reaction of N-(prop-2-en-1-yl)hydrazinecarbothioamide with substituted 2-hydroxybenzaldehydes afforded the corresponding Schiff bases which were used as ligands to obtain copper and cobalt coordination compounds Cu(NL^1–6)X · n H₂O (X = Cl⁻, \(\rm{NO}_3^-\); n = 0–3), Co(HL²)₂NO₃, and Co(NL⁶)₂Cl. The structure of the isolated complexes was determined by NMR spectroscopy and X-ray analysis. The complexes were tested for antimicrobial and antifungal activity against S. aureus, E. coli, and yeast-like fungi. Inhibitory effect of the initial thioamides and their complexes against human myeloid leukemia HL-60 cancer cell line was also studied.

The radical-cationic salts based on tetrathiafulvalene derivatives and bis(dicarbollide) transition metal complexes [3,3′-M(1,2-C₂B₉H₁₁)₂]⁻ (M = Co, Ni, Fe, Cr) are promising for the creation of new molecular conductive materials due to the almost unlimited possibilities of their modification. The relationships between the properties of both components of the cation-radical salts, their crystal structure, and electrical and magnetic properties have been analyzed on the basis of the literature and our own data. The effect of various substituents in metallacarborane anions on the structure and physical properties of their radical cation salts based on tetrathiafulvalene and its derivatives has been revealed. Data on the structure and properties of the radical cation salts with other borate anions are presented for comparison.

Thin conductive films have been obtained via dehydration and reduction of composite films based on polyvinyl alcohol and graphene oxide. Composition and structure of the nanocomposites as well as the features of heat-induced reduction and electroconductive properties of the products have been analyzed. It has been shown that dehydration of polyvinyl alcohol leads to the formation of additional contacts between the filler particles and significantly enhances the conductivity.

A novel series of amide 1,3,4-oxadiazole linked benzoxazole derivatives 12a–12j are synthesized and their anticancer activity is screened against four human cancer cell lines including A549 (Lung cancer), MCF7 (Breast cancer), A375 (Melanoma cancer), HT-29 (Colon cancer) using Combretastatin-A4 as a control drug. Among the synthesized compounds, 12c and 12g demonstrate potent anticancer activity against HT-29 cancer cell line with IC₅₀ values of 0.018 and 0.093 µM, respectively, which is higher than the standard drug.

Evaluation of stability constants of the complexes formed in solution by the biologically important ligands and metal ions can aid in understanding the application of metal complexes in chelation therapy. Hence, complexation equilibrium studies of the ligands (L), 3-formylpyridinethiosemicarbazone (H3FPT) and 3-formylpyridine-N⁴-methylthiosemicarbazone (H3FP4MT) with Zn(II) and Cd(II) metal ions (M) are carried out in 70% v/v DMF-water medium at 0.1M KNO₃ ionic strength and the stability constants are determined pH-metrically at 303 K. The binary complexes are formed in 1: 1 (M: L) ratio and are fairly stable. The binary complexes of H3FPT and H3FP4MT (L) with Zn(II), Cd(II) and Hg(II) ions are synthesized and characterized by various analytical and spectral techniques including elemental analysis, molar conductance, LC-MS, TGA, IR and ¹H NMR spectroscopy. According to the accumulated information, the complexes are polymeric (ML)n with n > 2, except that of Hg(II)-H3FP4MT, which is ML₂. The antioxidant activity of the ligands and their Zn(II) and Hg(II) complexes demonstrate higher activity than their corresponding ligands Cd(II) complexes. Antibacterial activity of the ligands and the complexes is tested against gram positive: Staphylococcus aureus, Bacillus subtilis and gram negative: Escherichia coli and Klebsiella pneumonia bacterial strains. Activity of complexes is determined to be higher than that of the corresponding free ligands.

A series of new 3-(2-substituted)-4-(oxothiazolidin-3-yl)-2-methylquinazolin-4(3H)-ones 1a–1k is synthesized by using the hybridization approach via one pot multicomponent reaction of 3-amino-2-methylquinazolin-4(3H)-one with substituted benzaldehyde, thioglycolic acid and N, N-dicyclohexylcarbodiimide in DMF media. Structures of the synthesized compounds are elucidated from the spectral data. Antidiabetic activity of the products is tested against streptozotocin induced diabetic rats at a dose of 200 mg/kg compared with standard Pioglitazone (15 mg/kg). Compounds 1b, 1d, 1f, and 1i demonstrate significant antidiabetic activity. Compounds 1b, 1d, 1f, and 1i are evaluated in vitro are tested for serum insulin, cholesterol, triglycerides, total protein, lipoprotein, and enzymes factors. Significant lowering of glycated hemoglobin level is induced by the compounds after 21 days of treatment. Mean±S.E.M. data accumulated are subjected to one-way analysis of variance (ANOVA) followed by Dunnett’s t-test. p < 0.001 was considered statistically significant. Histopathological results accumulated for the rats treated by compounds 1b, 1d and 1f confirm the significant recovery of pancreas destruction. Free energy of binding for all synthesized compounds is calculated using AutoDock 1.5.6 with peroxisome proliferator-activated receptor γ (PPAR γ; PDB ID: 4PRG). Among the synthesized compounds, 1d demonstrates significant binding energy value of −11.46 kcal/mol. The current study is expected to provide useful insight into the design of potential agents that can act as a platform for the development of future antidiabetic drugs.

1-Arylcyclopentane-1-carboxylic acids were synthesized by alkaline hydrolysis of the corresponding nitriles. Reactions of the acid chlorides with N,N-dialkylaminoalkyl-and hetarylalkylalkanols provided new aminoester derivatives of 1-arylcyclopentane-1-carboxylic acids. Sympatholytic and adrenolytic activity of the obtained amino esters hydrochlorides was studied.