Features of the Self-organization of Films Based on Triglycine under the Influence of Vapors of Organic Compounds

© 2020, Pleiades Publishing, Ltd. Abstract: The self-assembly of triglycine on the surface of highly oriented pyrolytic graphite and mica is studied by atomic force microscopy. The possibility of the formation of crystalline structures based on triglycine as a result of the action of vapors of organic compounds or water on its amorphous film is demonstrated. It is shown that organic compounds capable of forming hydrogen bonds affect the surface of films deposited onto these substrates. Organic compounds incapable of hydrogen bonding change the morphology of films deposited only onto the surface of pyrographite

Smart thermal behavior of tripeptide leucyl-leucyl-leucine towards vapors of binary mixture of benzene and tetrachloromethane

A new method for the determination of benzene vapors in a two-component mixture was proposed. This method is based on smart behavior of L-leucyl-L-leucyl-L-leucine (LLL) crystals, which are able to remember the included benzene. This memory is revealed as the sequential endo- and exothermic effects on the DSC curve under heating of LLL powder saturated with vapors of benzene in the temperature range above the endset point of benzene release. The enthalpies of endo- and exothermic effects are proportional to the benzene content in its binary vapor mixture with tetrachloromethane used to saturate the LLL powder. The reasons of the LLL memory are explained and the possibility to control the polymorphic state of the tripeptide using organic vapors was shown. The observed specific properties of LLL tripeptide may be used for qualitative and quantitative analysis of benzene in its mixture with other organic substances

Using fast scanning calorimetry to study solid-state cyclization of dipeptide L-leucyl-L-leucine

© 2020 Elsevier B.V. The possibility of using fast scanning calorimetry (FSC) to study the kinetics of the solid-state cyclization of dipeptide was demonstrated in the present work for the first time. The activation energy and Arrhenius constant of the cyclization of L-leucyl-L-leucine (Leu-Leu) were estimated. FSC data obtained at heating rates from 18,000 to 54,000 K min−1 were evaluated by non-isothermal kinetics. The dependence of the specific heat capacity cp on temperature was determined for linear and cyclic Leu-Leu dipeptides using differential scanning calorimetry (DSC) and FSC. The application of FSC allows studies of solid-state reactions for expensive substances and compounds synthesized in very small amounts

In-situ heavy oil aquathermolysis in the presence of nanodispersed catalysts based on transition metals

The aquathermolysis process is widely considered to be one of the most promising approaches of in-situ upgrading of heavy oil. It is well known that introduction of metal ions speeds up the aquathermolysis reactions. There are several types of catalysts such as dispersed (heterogeneous), water-soluble and oil soluble catalysts, among which oil-soluble catalysts are attracting considerable interest in terms of efficiency and industrial scale implementation. However, the rock minerals of reservoir rocks behave like catalysts; their influence is small in contrast to the introduced metal ions. It is believed that catalytic aquathermolysis process initiates with the destruction of C-S bonds, which are very heat-sensitive and behave like a trigger for the following reactions such as ring opening, hydrogenation, reforming, water–gas shift and desulfurization reactions. Hence, the asphaltenes are hydrocracked and the viscosity of heavy oil is reduced significantly. Application of different hydrogen donors in combination with catalysts (catalytic complexes) provides a synergetic effect on viscosity reduction. The use of catalytic complexes in pilot and field tests showed the heavy oil viscosity reduction, increase in the content of light hydrocarbons and decrease in heavy fractions, as well as sulfur content. Hence, the catalytic aquathermolysis process as a distinct process can be applied as a successful method to enhance oil recovery. The objective of this study is to review all previously published lab scale and pilot experimental data, various reaction schemes and field observations on the in-situ catalytic aquathermolysis process

Pillar[5]arenes as potential personage for DNA compactization and gene therapy

© 2020 Elsevier B.V. Here we demonstrated that pillar[5]arenes with counterions I− and Cl− show the ability to plasmid compactization and increasing bacterial transformation efficiently. Pillar[5]arenes have been tested for binding with palindromic decamer oligonucleotide and interacting with plasmid DNA. The complexation of pillar[5]arene with oligonucleotide has been shown by NMR- and CD-spectroscopy. Pillar[5]arenes form complexes with oligonucleotide in solution in the 1:1 or 1:2 stoichiometry. Molecular modeling allowed to constructs the models of these complexes. Pillar[5]arene interaction with the plasmid DNA have been studied using atomic force microscopy. According to AFM images pillar[5]arene-I− and pillar[5]arene-Cl− packed up the plasmid DNA to aggregates with diameter about 100 nm with different morphology. An increase in DNA transformation efficiency into bacterial cells has been shown for pillar[5]arenes with counterions I− and Cl−