Search

In vitro antitumor activity of some 4-(2-hydroxyaryl)-1,2,3-thidiazoles was studied against erythroleukemia (K562) and cervical carcinoma (HeLa) cell lines.

In vitro antitumor activity of some benzo[b]thiophenes with a tertiary amino group in the second position was studied against erythroleukemia (K562) and cervical carcinoma (HeLa) cell lines.

In vitro antitumor activity of some 4-(1,2,3-thiadiazol-4-yl)furans was studied against erythroleukemia (K562) and cervical carcinoma (HeLa) cell lines.

Benzo[h]isoquinoline scaffold is of interest as a rigid subunit that can be useful for constructing biologically active products. However, no good-yielded synthetic pathway to this ring system has been reported yet. Herein, a facile one-pot synthesis from N-aryl itaconimides and 1,3-diarylisobenzofuran via strong acid triggered skeletal rearrangement reaction is described. Theoretical study for this rearrangement is provided at M11/cc-pVDZ level of theory. Antitumor activity of obtained benzo[h]isoquinoline derivatives against human erythroleukemia K562 cell line was evaluated in vitro by MTS-assay.

Optogenetics and photopharmacology are two perspective modern methodologies for control and monitoring of biological processes from an isolated cell to complex cell assemblies and organisms. Both methodologies use optically active components that being introduced into the cells of interest allow for optical control or monitoring of different cellular processes. In optogenetics, genetic materials are introduced into the cells to express light-sensitive proteins or protein constructs. In photopharmacology, photochromic compounds are delivered into a cell directly but not produced inside the cell from a genetic material. The development of both optogenetics and photopharmacology is inseparable from the design of improved tools (protein constructs or organic molecules) optimized for specific applications. Herein, we review the main tools that are used in modern optogenetics and photopharmaclogy and describe the types of cellular processes that can be controlled by these tools. Although a large number of different kinds of optogenetic tools exist, their performance can be evaluated with a limited number of metrics that have to be optimized for specific applications. We classify these metrics and describe the ways of their improvement.

The relative cross section of processes attendant on the capture of an electron by 12-keV 3He2+ ions are measured by time-of-flight mass spectrometry for leucine (C6H13NO2), methionine (C5H11NO2S), and glutmic acid (C5H9NO4) molecules. No differences between the formation relative cross sections of different fragment ions for the D- and L-enantiomeric forms of the amino acids are revealed. The spectrum of glutamic acid fragments taken at temperatures above 110°C is explained by decomposition of the acid with the formation of pyroglutamic acid (C5H7NO3) and water. The results are compared with published data on fragmentation of the same molecules via electron-impact ionization.

The physicochemical conditions of the aqueous environment at the dawn of biological evolution were of key importance for abiogenic peptide synthesis. Recently, we have shown theoretical and experimental evidence for the unique role of potassium ions in the exponential acceleration of undirected peptide synthesis from L-glutamic acid. These data have confirmed our previous hypothesis that the first protocell emerged in a potassium rather than sodium-rich aqueous solution (seawater). The present work provides experimental data for an interpretation of concentration dependence and of optimal effective concentration of potassium and sodium ions in L-glutamic acid peptide formation.

Formal aza-Diels-Alder (Povarov) reaction of 6,6-dimethylfulvene with aromatic imines is described for the first time.

A reaction of 1,3-diphenylisobenzofuran with N-arylitaconimides gives the [4+2] cycloaddition products with the 11′-oxaspiro[pyrrolidine-3,9′-tricyclo[6.2.1.0 2,7 ]undeca-2′,4′,6′-triene-2,5-dione] skeleton as a single diastereomer.

The first example of 1,3-dipolar cycloaddition reactions of nitrones to vinylidenecyclopropanes is described. The nitrones react with the C1′–C2′ double bond of vinylidenecyclopropanes to give the corresponding 4-cyclopropylidene-isoxazolidines in moderate yields.

The synthesis and dehydrohalogenation of diethyl halocyclopropane-1,1-dicarboxylates prepared from diethyl ethylidene- and benzylidenemalonates are described.

Substituted methyl 2,3,7-triazabicyclo[3.3.0]oct-3-ene-4-carboxylates and 1,2,7-triazaspiro[4.4]non-2-ene-3-carboxylates react with N-iodosuccinimide (or the system iodine-silver trifluoroacetate) to give, respectively, methyl 6-iodo-3-azabicyclo[3.1.0]hexane-6-carboxylates or methyl 1-iodo-4,6-dioxo-5-azaspiro[2.4]heptane-1-carboxylates as mixtures of exo and endo isomers.

Esters of 4-R-4,5-dihydro-1H-pyrazole-3,5,5-tricarboxylic acids with chlorine yield esters of 4-R-5-chloro-4,5-dihydro-3H-pyrazole-3,3,5-tricarboxylic acids that at thermolysis provide the esters of the corresponding 2-chlorocyclopropanetricarboxylic acid. The same esters react with bromine in dichloromethane at room temperature to give a mixture of esters of the corresponding 1H-pyrazole-3,5-dicarboxylic acids and 5-bromo-4,5-dihydro-3,3,5-tricarboxylic acids. From 5,5-diethyl 3-methyl 4,5-dihydro-1Hpyrazole-3,5,5-tricarboxylate and N-iodosuccinimide or a system iodine-silver trifluoroacetate we obtained 1,1-diethyl 2-methyl 2-iodocyclopropane-1,1,2-tricarboxylate.

Substituted 6,8-dioxo-2,3,7-triazabicyclo[3.3.0]oct-3-ene-4-carboxylates react with N-fluoropyridinium tetrafluoroborate to give mixtures of exo and endo isomers of 6-fluoro-2,4-dioxo-3-azabicyclo[3.1.0]hexane-6-carboxylates. Analogous reaction of 6,8-dioxo-1,2,7-triazaspiro[4.4]non-2-ene-3-carboxylates results in formation of syn,anti-isomeric 1-fluoro-4,6-dioxo-5-azaspiro[2.4]heptane-1-carboxylates.

The salt-induced peptide formation is important for assessing and approaching schemes of molecular evolution. Here, we present experimental data and an exactly solvable kinetic model describing the linear polymerization of L-glutamic amino acid in water solutions with different concentrations of KCl and NaCl. The length distributions of peptides are well fitted by the model. Strikingly, we find that KCl considerably enhances the peptide yield, while NaCl does not show any catalytic effect in most cases under our experimental conditions. The greater catalytic effect of potassium ions is entirely interpreted by one and single parameter, the polymerization rate constant that depends on the concentration of a given salt in the reaction mixture. We deduce numeric estimates for the rate constant at different concentrations of the ions and show that it is always larger for KCl. This leads to an exponential increase of the potassium- to sodium-catalyzed peptide concentration ratio with length. Our results show that the ion-catalyzed peptides have a higher probability to emerge in excess potassium rather than in sodium-rich water solutions.

The reactions of 1,1-diaryl-2-(diphenylvinylidene)cyclopropanes and 1,1-diaryl-2-(2-phenylpropenylidine) cyclopropanes with aromatic amines in the presence of BF3·Et2O leads to the formation of pyrrolidine derivatives.

Substituted methyl 2,3,7-triazabicyclo[3.3.0]oct-3-ene-4-carboxylates and 1,2,7-triazaspiro[4.4]non-2-ene-3-carboxylates react with N-iodosuccinimide (or the system iodine-silver trifluoroacetate) to give, respectively, methyl 6-iodo-3-azabicyclo[3.1.0]hexane-6-carboxylates or methyl 1-iodo-4,6-dioxo-5-azaspiro[2.4]heptane-1-carboxylates as mixtures of exo and endo isomers.

Substituted 6,8-dioxo-2,3,7-triazabicyclo[3.3.0]oct-3-ene-4-carboxylates react with N-fluoropyridinium tetrafluoroborate to give mixtures of exo and endo isomers of 6-fluoro-2,4-dioxo-3-azabicyclo[3.1.0]hexane-6-carboxylates. Analogous reaction of 6,8-dioxo-1,2,7-triazaspiro[4.4]non-2-ene-3-carboxylates results in formation of syn,anti-isomeric 1-fluoro-4,6-dioxo-5-azaspiro[2.4]heptane-1-carboxylates.

Esters of 4-R-4,5-dihydro-1H-pyrazole-3,5,5-tricarboxylic acids with chlorine yield esters of 4-R-5-chloro-4,5-dihydro-3H-pyrazole-3,3,5-tricarboxylic acids that at thermolysis provide the esters of the corresponding 2-chlorocyclopropanetricarboxylic acid. The same esters react with bromine in dichloromethane at room temperature to give a mixture of esters of the corresponding 1H-pyrazole-3,5-dicarboxylic acids and 5-bromo-4,5-dihydro-3,3,5-tricarboxylic acids. From 5,5-diethyl 3-methyl 4,5-dihydro-1Hpyrazole-3,5,5-tricarboxylate and N-iodosuccinimide or a system iodine-silver trifluoroacetate we obtained 1,1-diethyl 2-methyl 2-iodocyclopropane-1,1,2-tricarboxylate.