Heterylimidazoles

The condensation of heterocyclic aldehydes with aromatic -diketones in the presence of ammonium acetate in acetic acid has given 4,5-diaryl-2-quinolinylimidazoles and 4,5-diaryl-2-(acridin-9-yl) imidazoles. The oxidation of the latter with K₃Fe(CN)₆ in an alkaline medium has given the corresponding biimidazolyls, which possess photochromic and thermochromic properties.For Communication I, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1105–1108, August, 1973.     

Star Poly(2-alkyl-2-oxazolines) Based on Octa-(chlorosulfonyl)-calix[8]arene

Starlike thermosensitive polymers were synthesized by cationic polymerization of 2-alkyl-2-oxazolines using a new type of sulfonyl chloride macroinitiator. It was confirmed that the polymerization on the multisulfonyl chloride initiator proceeds in the absence of irreversible chain termination and makes it possible to obtain polymers with a narrow molecular weight distribution. The polymers demonstrate a lower critical solution temperature and an ability to form complexes with hydrophobic low-molecular-weight compounds.     

Synthesis of unsaturated esters of pyridine-and quinolinecarboxylic acids

The vinyl esters of pyridine-2-and -4-carboxylic acids, the propargyl esters of pyridine-2-, -3-, and-4-carboxylic acids, the vinyl, allyl, and propargyl esters of quinoline-2-, -4-, and -8-carboxylic acids, and the allyl ester of 2-methylisonicotinic acid have been synthesized.     

Gas Chromatographic Determination of Diacetylmorphine with Mass Spectrometric Detection

The possibility of determining diacetylmorphine traces in various matrices by gas chromatography with mass spectrometric detection is demonstrated. Diacetylmorphine can be reliably determined by gas chromatography–mass spectrometry in the range 0.02–7.5 g/mL. A procedure is developed for the quantitative determination of diacetylmorphine and its concomitants, including acetylated opioid derivatives, in forensic samples. The detection limit for diacetylmorphine without preconcentration is 0.01 g/mL. The detection limit in the selective-ion monitoring mode with preconcentration is 1 × 10^–4 g/mL.     

Thermodynamic properties of three adamantanols in the ideal gas state

The enthalpies of sublimation and the saturated vapor pressure of 1-adamantanol (1-Adol), 2-adamantanol (2-Adol) and 2-methyl-2-adamantanol (2-Me-2-Adol) were measured. Thermodynamic functions of the compounds under study in the ideal gas state between 100 and 1000 K were calculated by the statistical thermodynamic methods. The sets of wave numbers of normal vibrations for adamantanols were obtained by semi empirical calculation (MINDO3 И MNDO/d). The experimental entropies for gaseous adamantanols and the calculated values were in the satisfactory agreement.     

On a model of vortex motion of an incompressible polymeric liquid in the axial zone

Some nonstationary mathematical model is constructed to describe the vortex motion of an incompressible polymeric liquid. In the stationary case, several partial solutions for this model are found. The derivation of a variant of this model is given for the case when the pressure along the axis is independent of time.     

Cell proliferation in normal and malignant transformed cells: thermodynamic model of signal transduction

We present a new thermodynamic model for the mechanism of activation and regulation of cell proliferation in the G1 stage. In this model, the interactions between growth factors and transmembrane proteins play a crucial role in cell growth control for a normal tissue-culture system. We calculate a phase diagram of normal and malignant transformed states of a cell signal transduction system. We propose thermodynamic reasons why cancer cells can continually grow without activation by the growth factors.     

Dithiophosphate-Induced Redox Conversions of Reduced and Oxidized Glutathione

Phosphorus species are potent modulators of physicochemical and bioactive properties of peptide compounds. O,O-diorganyl dithiophoshoric acids (DTP) form bioactive salts with nitrogen-containing biomolecules; however, their potential as a peptide modifier is poorly known. We synthesized amphiphilic ammonium salts of O,O-dimenthyl DTP with glutathione, a vital tripeptide with antioxidant, protective and regulatory functions. DTP moiety imparted radical scavenging activity to oxidized glutathione (GSSG), modulated the activity of reduced glutathione (GSH) and profoundly improved adsorption and electrooxidation of both glutathione salts on graphene oxide modified electrode. According to NMR spectroscopy and GC–MS, the dithiophosphates persisted against immediate dissociation in an aqueous solution accompanied by hydrolysis of DTP moiety into phosphoric acid, menthol and hydrogen sulfide as well as in situ thiol-disulfide conversions in peptide moieties due to the oxidation of GSH and reduction of GSSG. The thiol content available in dissolved GSH dithiophosphate was more stable during air oxidation compared with free GSH. GSH and the dithiophosphates, unlike DTP, caused a thiol-dependent reduction of MTS tetrazolium salt. The results for the first time suggest O,O-dimenthyl DTP as a redox modifier for glutathione, which releases hydrogen sulfide and induces biorelevant redox conversions of thiol/disulfide groups.     

Incompressible Polymer Fluid Flow Past a Flat Wedge

A problem of an incompressible polymer fluid flow past an infinite flat wedge is considered. The flow moves parallel to the plane of symmetry of the wedge and normal to the wedge rib. It is demonstrated that two surfaces of strong discontinuities are needed for the no-slip condition to be satisfied on the wedge surface. Steady solutions of the problem are studied, and the flow is shown to be asymmetric with respect to the plane of symmetry of the wedge.