Infrared Spectroscopic Study of Trifluoromethoxybenzene⋯Methanol Complexes Formed in Superfluid Helium Nanodroplets

We have studied the intermolecular complex formation between trifluoromethoxybenzene and methanol (CD3OD) by infrared spectroscopy in superfluid helium droplets in the spectral range of 2630 and 2730 cm-1, covering the...

Extremely superb efficiency and lifetime of deep blue phosphorescent OLEDs by introducing a hypsochromic emissive intermolecular complex (HEIC) with a negligibly small ΔEST and fast reverse intersystem crossing rate

Concept of a hypsochromic emissive intermolecular complex (HEIC) compared with the conventional exciplex and electroplex. A mixed host system with HEIC exhibits blue-shifted electroluminescence as well as photoluminescence.

Analysis of the interaction between N-acetylneuraminic acid and disaccharides on silica surface

Nanocomposites based on biomolecules and highly dispersed silica are quite promising for use in many fields of biotechnology. There are many methods of obtaining such materials, in particular, adsorption from liquid or gas phases. Saccharides and their derivatives are present in the human body, they are involved in metabolic process, thus it is reasonable to use them while working with biomolecules. The work considers such disaccharides as sucrose, lactose and N-acetylneuraminic acid (NANA). Being a part of glycoproteins and glycolipids, NANA is also considered to be a carbohydrate. The main objective of the study was to study the ways of interaction of NANA on the disaccharide-modified silica surface. The methods of quantum chemistry have been used to find the probable structures of three-component adsorbtion complexes at molecular level and to clarify the mutual influence of these compounds in adsorbtion process. An analysis of the results of quantum chemical calculations shows that the adsorption of an anion of N-acetylneuraminic acid on silica surface is less likely than in its molecular form. Molecules of N-acetylneuraminic acid, disaccharides and silica form intermolecular complexes due to intermolecular hydrogen bonds between polar functional (mainly –OH) groups of the analytes. The sucrose dimer is 85.4 kJ/mol stronger than the lactose one. The sucrose molecule also forms a 38.1 kJ/mol stronger intermolecular complex with the N-acetylneuraminic acid molecule compared to a similar complex where lactose is used as a disaccharide. The highest energy (245.2 kJ/mol) is released when a silica cluster interacts with the intermolecular complex of N-acetylneuraminic acid and sucrose provided silica and the sucrose molecule are in a direct contact with each other. Therefore, as studies have shown, the adsorption of N-acetylneuraminic acid is possible if silica surface is pre-modified with disaccharides. The results of quantum chemical modeling confirm the obtained experimental data.

Involvement of the vanilloid receptor 1 in the mechanisms of analgesic effect of amizonum

SUMMARY The study of features of pharmacodynamics of a new analgesic is an important and urgent task of modern pharmacology. These data allow us to clarify the nosology for application of an analgesic and to create a theoretical background to optimize its use. An effect mediated by the transient receptor potential cation channel, subfamily V, member 1 (TRPV1) activation can also be an effective mechanism of the analgesic action. We evaluated the possibility of TRPV1 participation in implementation of the analgesic effect with the antiviral action of amizonum during the experiment. It is known that amino acids Tyr511 and Ser512 are the main components of the active site of TRPV1. In this connection, dipeptide Tyr-Ser has been completely synthesized as a model of the active site of TRPV1. In the experiment model this was shown, using the spectrophotometric method, with the formation of the “capsaicin - Tyr- Ser” intermolecular complex at the level of the stability constant Kkor=0.998 and Kr=0.3•10-4 L/mol and the “amizonum - Tyr-Ser” weak intermolecular complex Kr=0.05•104 L/mol; Kkor= 0.995, respectively. The data verification was carried out in experiments in vitro (isolated ratportal vein) and in vivo (Tail-flick model), with the TRPV1 agonist. It was shown that the amplitude of smooth muscle (SM) contraction of the portal vein at a capsaicin concentration 0.1 μmol/L, 0.5 μmol/L capsazepine, and 1.0 μmol/L amizonum was +30.3±5.3%, -3.2± 2.7% and +7.1±3.2% from initial level, respectivelly. In a combined application of amizonum with capsaicin or capsazepine, the amplitude of contraction of the SM portal vein was 20.1± 1.3% and -3.0±1.4%, respectively. This indicates the absence of action of amizonum under combined use of capsaicinoids. The Tail-flick model showed atypical potentiation of the amizonum antinociception with the use of capsaicin. The obtained data suggest the low probability of the participation of TRPV1 in the implementation of the antinociceptive action of amizonum.

Significant evidence of C⋯O and C⋯C long-range contacts in several heterodimeric complexes of CO with CH3–X, should one refer to them as carbon and dicarbon bonds!

An illustrated example of a ‘dicarbon bond’ formed between a pair of two carbon atoms of the OC⋯CH3–Cl3intermolecular complex, one corresponding to the methylated carbon in 1,1,1-trichloro-ethane (CH3–Cl3) and one to the carbon in the carbon dioxide (CO) molecule.

A Comparative Study of the Influence of Aquaous 2,2,2-Trifluoroethanol And Ethanol on the Structural Organization, the Kinetic and Thermodynamic Properties of Oligodeoxyribonucleotides Intermolecular Complex Formation

A comparative study of the structural organization, thermodynamic and kinetic properties of the oligodeoxynucleotides complexes formation in the presence of 2,2,2-trifluoroethanol and ethanol in aqueous solution (volume fraction of alcohol 0 to 50 %) was performed. No significant changes in the circular dichroism spectra of oligonucleotides and their complexes at the adding of 50 % v/v alcohol into a solution, was observed, and they retain the profile typical for B-form DNA. The study of the thermal stability of DNA duplexes showed that the increase in the volume fraction of ethanol in the aqueous solution up to 50 % results in a linear decrease in the melting temperature of the intermolecular DNA complexes. In the case of the 2,2,2-trifluoroethanol we observed atypical dependence of thermal stability of DNA duplexes on the fraction of the fluorine-containing co-solvent. Increasing the alcohol fraction from 0 to 20% v/v led to a linear decrease of the melting point of the complex. A further increase in the volume fraction of alcohol (up to 50 %) did not change the thermal stability of the duplexes. It was shown, that the destabilizing effect of the two co-solvents is due to the increase of the dissociation rate constant of the complex and has mainly entropic nature. On the example of oligonucleotides complexes of 8, 12, 15 and 20 base pairs length the possibility of prediction DNA duplexes thermal stability was shown. A model taking into account the change of a number solvent molecules interacting with nucleic acids at the duplex formation in aqueous ethanol (50 % v/v) or trifluoroethanol (20 % v/v) was applied. An accuracy of melting temperature prediction was 1.3 and 0.6 degrees. Using this model, we found that the addition of alcohols in solution leads to an increase in the number of water molecules that bind to a complementary pair of nucleotides at the formation of intermolecular complex (in the presence of ethanol or trifluoroethanol 0.51 ± 0.09 and 1.33 ± 0.12, respectively). At the same time, alcohols interacted with single-stranded oligonucleotides and double-stranded in the same way