French-Ukrainian Journal of Chemistry
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The interaction of homophthalic anhydride with (triphenylphosphoranylidene)acetates
Get PDFIn the study of the interaction of homophthalic anhydride and methyl (triphenylphosphoranylidene)acetate, along with (1-oxo-1H-isochromen-3‑yl)acetate obtaining, two minor products – (1,3-dioxo-1,2,3,4-tetrahydronaphthalene-2-yl)acetate and 2‑((1‑oxo-1H-isochromen-3-yl)methyl)benzoic acid – had been isolated. The action of tert‑butyl (triphenylphosphoranylidene)acetate on homophthalic anhydride didn’t lead to Wittig reaction; the encumbered ylide demonstrated only its basicity, and products of homophthalic anhydride self-condensation – 2‑((1‑oxo-1H-isochromen-3-yl)methyl)-benzoic acid and 12-hydroxy-5H-dibenzo[c,g]chromen-5-one – were formed
Physico-chemical properties of β-diketone phosphorus-containing dendrimers
Get PDFProtolytic, absorbance and fluorescence properties of β-diketone phosphorus-containing dendrimers based on cyclotriphosphazene core were studied. Dendrimer solutions in acetone are characterized by intense absorbance band at ≈ 340 nm (ε340≈ 8.5·104L/mol·сm) and fluorescence band with maximum at 440 nm. Position of these maxima does not change in various solvents, unlike the bands of monomer β-diketone. It was found that dendrimer aggregation is accompanied by appearance of a second absorbance band ε400≈ 4.5·103L/mol·сm, by red shift of emission spectra ∆λ ≈ 10 nm and also by decrease in surface tension of acetone solution. Ability of dendrimer aggregates to solubilize organic substrates was observed with the fluorescent indicator acridine
NH3(CH2)6NH3SiF6 catalyzed highly efficient synthesis of benzimidazoles, benzoxazoles, benzothiazoles, quinoxalines and pyrimidin-2-ones/thiones
Get PDFHerein, we describe a simple, highly efficient and environmentally friendly protocol for the synthesis of benzimidazoles, benzoxazoles, benzothiazoles, 3,4-dihydropyrimidin-2-ones/ thiones and quinoxalines derivatives using hybrid crystal NH3(CH2)6NH3SiF6 as a catalyst. Use of recyclable catalyst, easy work-up procedure, excellent yields, short reaction times and scalability are the important practical features of the present protocol
Beckmann Rearrangement of 3-carboxybicyclo[3.3.1]nonane and [3.2.1]octane Oximes
Get PDFRegiospecific Beckmann rearrangement of substituted 2-hydroximinonorbornanone carboxylic acids has been investigated. Selective formation of new functionalized 10-oxo-9-azabicyclo[3.3.2]decanes and 7-oxo-6-azabicyclo[3.2.2]nonanes in good yield has been demonstrated. Presence of neighboring carboxylic group allows conducting of Beckmann rearrangement of strained bicyclic compound
Spectroscopic Studies on the Interaction between Tilorone and Human Serum Albumin
Get PDFUnder physiological conditions, in vitro interaction between the antiviral drug 2,7-bis[2-(diethylamino)ethoxy]-9-fluorenone dihydrochloride (Tilorone, TIL) and human serum albumin (HSA) was investigated at excitation wavelength 280 nm and at different temperatures (298 K and 313 K) by fluorescence emission spectroscopy. TIL showed a strong ability to quench the intrinsic fluorescence of HSA through a static quenching procedure. The binding constant is estimated as KA =7.19× 104L·mol-1 at 298 K. The enthalpy change (ΔHº) and entropy change (ΔSº) were derived to be negative values. A value of 1.63 nm for the average distance r between TIL (acceptor) and tryptophan residues of HSA (donor) was derived from the fluorescence resonance energy transfer
N-Phenacylthiazolium Salts as Inhibitors of Cholinesterases
Get PDFInhibition of acetylcholinesterase is considered as a promising approach for treatment of neurodegenerative disorders including Alzheimer's disease. In this study, we demonstrated that 5-substituted N-phenacylthiazolium derivatives are capable of inhibiting acetylcholinesterase and butyrylcholinesterase activities with IC50 values in the micromolar range. Some of the new thiazolium-based inhibitiors showed more than 10-fold selectivity for butyrylcholinesterase. Kinetic experiments and molecular docking were performed for understanding the inhibition mechanisms
Dissimilar Associates of Dyes in Aqueous Solutions: Experimental Study and Computer Simulation
Get PDFDissimilar cation-anionic association of dyes («cyanine+oxyxanthene», «cyanine+sulfonepthalein») has been regularly investigated in aqueous solutions. Experimental (by spectrophotometry) and theoretical (by semiempirical) methods were used. The basic regularities of association processes have been discussed. It is shown that the change in the stability of associates has a systematic character both in the series of singly charged and doubly charged anions. The experimentally determined values (of equilibrium constant of association) and simulated values (of standard enthalpy of hydration of associates) are mutually consistent. The standard enthalpy of formation and the most probable structures of associates have been determined
Compositions of Anticancer Drug with Micellar Nanocarriers and Their Cytotoxicity
Get PDFAsymmetric diblock (DBC) and triblock (TBC) copolymers contained biocompatible chemically complementary polyacrylamide and poly(ethylene oxide) (PAAm-b-PEO-b-PAAm) or its monomethyl ether (MEPEO-b-PAAm), and also partially hydrolyzed triblock copolymer derivative (TBChydr) were used to create micelles of a special type. The micelles obtained are characterized by small CMCs and large values of the Gibbs micellization energy, thus indicating a high stability of DBC, TBC and TBChydr micelles in aqueous solutions and the capabilities of their use to encapsulate and deliver poorly soluble and/or toxic drugs in living organism. Morphological features and size of DBC and TBC micelles were determined by TEM. The electron images demonstrated spherical micelles of a polymolecular type, monomolecular type and separate micelle aggregates. TBC and TBChydr micelles were used to examine in vitro anticancer activity of their compositions with doxorubicin (Dox). The created micelle systems showed the enhanced cytotoxicity as compared to individual Dox against murine leukemia cells of L1210 line, murine transformed fibroblasts of L929 line and human T-leukemia cells of Jurkat line and allow to achieve a high efficacy at low Dox concentrations (0,1÷3 µg·cm-3) that opens the great prospects for essential decrease in drug dose at chemotherapy
7-Substituted pyrrolo[2,3-d]pyrimidines for the synthesis of new 1-deazapyrimido[1,2,3-cd]purines
Get PDFFew examples of new heterocyclic 1-deazapyrimido[1,2,3-cd]purine derivatives were synthesized by intramolecular cyclization of methyl 7-(oxiran-2-ylmethyl)-7H-pyrrolo[2,3-d]pyrimidine-6-carboxylates. The latter were obtained by iodolactonization of 7-allylpyrrolo[2,3-d]pyrimidine-6-carboxylic acids
Study of Calixarene Complexation with Biologically Active
Get PDFHost-Guest complexation of octakis(diphenoxyphosphoryloxy)tetramethylcalix[4]resorcinarene CRA and 5,17-bis-(N-tolyliminomethyl)-25,27-dipropoxycalix[4]arene CA with bio relevant aromatic, pyridine and diterpenoid carboxylic acids in water-organic solution had been studied by the RP HPLC and molecular modelling methods. The stability constants KA (387-1914 М-1) of the supramolecular complexes had been determined. It was shown the Host-Guest interactions are depended on structure of the Host molecules and log P values of the Guests. The complexation is determined by the hydrogen bonds of the COOH group of the carboxylic acids with P=O oxygen atom of diphenoxyphosphoryl group of the calixresorcinarene CRA, and oxygen or nitrogen atoms located on the lower or the upper rim of the calixarene CA