Publications by authors named "Leonid Kovalenko"

Natural and synthetic phytohormones are widely used in agriculture. The synthetic cytokinin ethylenediurea (EDU) induces protection in plants against ozone phytotoxicity. In our study, new hybrid derivatives of EDU were synthesized and tested for phytoactivity.

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Based on the LiLaTiO compound, a ceramic membrane for a photoelectrochemical cell was created. The microstructure, phase composition, and conductivity of a semiconductor photoelectrode and a ceramic membrane were studied by using various experimental methods of analysis. A ceramic Li conducting membrane that consisted of LiLaTiO was investigated in solutions with different pH values.

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Natural cytokinines are a promising group of cytoprotective and anti-tumor agents. In this research, we synthesized a set of aryl carbamate, pyridyl urea, and aryl urea cytokinine analogs with alkyl and chlorine substitutions and tested their antiproliferative activity in MDA-MB-231, A-375, and U-87 MG cell lines, and cytoprotective properties in HO and CoCl models. Aryl carbamates with the oxamate moiety were selectively anti-proliferative for the cancer cell lines tested, while the aryl ureas were inactive.

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Article Synopsis
  • The study examines how different ratios of the starting reagents (PbI2: {CHNHI + CHNHCl}) influence the microstructure and electrical properties of organic-inorganic perovskite films (CHNHPbICl).
  • Increasing the reagent ratio from 1:1 to 1:2 significantly enhances crystallinity, while further increases to 1:3 yield only slight changes, and the films' morphology shifts from needle-like to roundish and faceted particles with increasing ratios.
  • The best electrical properties are observed at a 1:2 ratio, where charge mobility decreases but overall conductivity peaks due to a balance between improved crystallinity and reduced grain size.
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The 1,4-dioxane derivative of cobalt bis(dicarbollide) reacts with dialkylsulfides and triphenylphosphine to give the corresponding sulfonium and phosphonium derivatives [8-L(CH2CH2O)2-3,3'-Co(1,2-C2B9H10)(1',2'-C2B9H11)] (L = SMe2, S(CH2CH2)2O, PPh3). The treatment of the triphenylphosphonium derivative with sodium hydroxide results in contraction of the side chain with formation of [8-HOCH2CH2O-3,3'-Co(1,2-C2B9H10)(1',2'-C2B9H11)](-). The same product was obtained by treatment of the dimethylsulfonium derivative with the poorly nucleophilic base t-BuOK, whereas the stronger nucleophiles induce the sulfur demethylation to give [8-MeS(CH2CH2O)2-3,3'-Co(1,2-C2B9H10)(1',2'-C2B9H11)](-).

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Raltegravir was the first HIV-1 integrase inhibitor that gained FDA approval for use in the treatment of HIV-1 infection. Because of the emergence of IN inhibitor-resistant viral strains, there is a need to identify innovative second-generation IN inhibitors. Previously, we identified 2-thioxo-4-thiazolidinone (rhodanine)-containing compounds as IN inhibitors.

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We developed the synthesis of a series of thiophene-fused tetracyclic analogues of the antitumor drug ametantrone. The reactions included nucleophilic substitution of methoxy groups in 4,11-dimethoxyanthra[2,3-b]thiophene-5,10-diones with ethylenediamines, producing the derivatives of 4,11-diaminoanthra[2,3-b]thiophene-5,10-dione in good yields. Several compounds showed marked antiproliferative potency against doxorubicin-selected, P-glycoprotein-expressing tumor cells and p53(-/-) cells.

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