PHYSICOCHEMICAL PROPERTIES AND BIOLOGICAL ACTIVITY OF THE NEW ANTIVIRAL SUBSTANCE

Objective: To develop a set of quality control procedures for the promising antiviral pharmaceutical substance L-histidyl-1-adamantylethylamine dihydrochloride monohydrate, a derivative of rimantadine. Methods: Substances and solvents: synthesized in laboratory L-histidyl-1-adamantylethylamine dihydrochloride monohydrate (H-His-Rim•2HCl•H2O), rimantadine hydrochloride (Rim•HCl), 99%, ethanol 96%, N, N-dimethylformamide (DMF) anhydrous, 99.8% and n-hexane anhydrous, 95%, deionized high-resistance water (18.2 MΩ•cm at 25 °C, Milli-Q system), silver nitrate. Infrared (IR) Spectroscopy–Cary 630 Fourier Transform IR Spectrometer, elemental analysis–elemental composition analyzer CHNS-O EuroEA3000, ultraviolet (UV) spectrometry–Cary-60 spectrophotometer, polarimetry–POL-1/2 polarimeter with an external Peltier module, granulometric analysis by optical microscopy (Altami BIO 2 microscope) and low-angle laser light scattering (LALLS)–Master Sizer 3600, measurement of potential for hydrogen–potentiometer PB-11, Spirotox method–the study of temperature dependences of Spirostomum ambiguum lifetime to characterize the biological activity of the studied compounds. Results: The substance H-His-Rim•2HCl•H2O is an amorphous yellowish powder, slightly soluble in water, soluble in ethanol, freely soluble in N, N-dimethylformamide, and practically insoluble in n-hexane. A study of the elemental composition has confirmed the authenticity of H-His-Rim•2HCl•H2O. Comparison of the spectral characteristics of H-His-Rim•2HCl•H2O and Rim•HCl by IR spectroscopy and UV spectrometry confirmed the authenticity of the substance. The racemic form of the substance Rim•HCl with an insignificant amount of impurity of the levorotatory enantiomer was proved polarimetrically: α =-0.0126±0.0003 (1% aqueous solution, 20±0.5 °С). The specific optical rotation of 1% aqueous solution H-His-Rim•2HCl•H2O . In 1% ethanol solution -10.32±0.12. Using the method of laser light diffraction for a substance H-His-Rim•2HCl•H2O, the dimensional spectra «fraction of particles, %-d, μm» were characterized, the maximum of which in hexane is in the region of 40–50 μm. Arrhenius’s kinetics on the Spirotox model established statistically significant differences in ligand-receptor interactions, which are characterized by values of observed apparent activation energy °bsEa, kJ/mol: 132.36±1.55 for H-His-Rim•2HCl•H2O and 176.15±0.48 for Rim•HCl. Conclusion: The developed set of methods for assessment of physical and chemical properties and biological activity of a new antiviral substance H-His-Rim•2HCl•H2O is the basis for establish of regulatory documentation

DEUTERIUM AS A TOOL FOR CHANGING THE PROPERTIES OF PHARMACEUTICAL SUBSTANCES (REVIEW)

The review is devoted to the influence of the hydrogen isotope–deuterium on biological models of organisms and the biological activity of pharmaceutical substances. The positions of the influence of deuterium on the properties of active pharmaceutical ingredients and excipients are examined from different perspectives. The first position reflects an increase in the kinetic isotope effect (KIE) in processes involving known pharmaceutical substances in aqueous solutions with a deuterium/protium ratio (D/H) below natural. For the first time, the dose-response diagram shows the identity of deuterium with essential trace elements, when a deficiency and excess of an element reduces the organism's vitality. Improved kinetic characteristics are demonstrated for the molecular and organism levels of different hierarchical gradations. In particular, they consist in the possibility of increasing the dissolution rate of substances by influencing the carbohydrate mutarotation processes and the optical activity of chiral substances, increased accumulation of essential elements in medicinal plants and other processes associated with a possible change in metabolic pathways in the cell and the organism as a whole. The second considered position of the influence of deuterium is associated with the use of deuterated substances–new compounds or obtained by substitution of protium in known protium analogues. The KIE is presented, which is expressed in a decrease in the biotransformation rate as a result of deuteration, it allows predicting a rapid development of the new direction in the development of drugs. Having an identical therapeutic effect, deuterated analogs provide improved pharmacokinetic characteristics, such as reduced toxicity, blocked epimerization of optically active substances, and a change in the mechanisms of biotransformation. The obtained results make it possible to predict the mechanisms of the effect of deuterium on the biochemical transformations of pharmaceutical substances in the organism

POLARIMETRIC RESEARCH OF PHARMACEUTICAL SUBSTANCES IN AQUEOUS SOLUTIONS WITH DIFFERENT WATER ISOTOPOLOGUES RATIO

Objective: Methodology development for quality control of optically active pharmaceutical substances based on water isotopologues. Methods: Solutions of L-ascorbic acid, glucose, galactose and valine stereoisomers were prepared using deuterium depleted water (DDW-«light» water, D/H=4 ppm), natural deionized high-ohmic water (BD, D/H=140 ppm), heavy water (99.9% D2O). The optical rotation was observed using an automatic polarimeter Atago POL-1/2. The size distribution of giant heterogeneous clusters (GHC) of water was recorded by low angle laser light scattering (LALLS) method. Results: The infringement of Biot's Law was found for solutions of ascorbic acid, expressed in the absence of a constant value of the specific optical rotation  at a concentration of below 0.1%, depends on the D/H ratio. The inequality was established in absolute values of optical rotation for L-and D-isomers of valine in solutions with different ratios of hydrogen isotopologues. The mutarotation of glucose confirmed the first-order kinetics, and the activation energies were statistically distinguishable for BD and DDW. The mutarotation of the natural galactose D-isomer proceeded with a lower energy consumption compared to the L-isomer. In heavy water, the mutarotation of monosaccharides had different kinetic mechanisms. Polarimetric results correlated with the number and size of GHC, which confirmed the possibility of chiral solvent structures induction by optically active pharmaceutical substances. Conclusion: In the optically active pharmaceutical substances quality control there should be considered the contribution of induced chiral GHC of water to the optical rotation value that depends on the isotopic D/H ratio, the substance nature and the form of its existence at a given pH

Induction and migration of cryptic/defective Salmonella enterica prophages as a consequence of infection with lytic phages is an additional factor in stability of a coevolutionary vector

The influence of infection of natural isolates of Salmonella enterica with lytic (nonlysogenic) phages on the expression of resident cryptic or defective prophages in host bacteria was studied. The induction of defective/cryptic phages after infection with nonlysogenic phages and packaging of bacterial chromosomal fragments in capsids of defective phages is demonstrated. This may lead to migration and wide distribution of both the genomes of defective phages per se and various fragments of the bacterial chromosome (including pathogenic islands) in new bacterial strains with concomitant change of their properties, the acquired new features of pathogenicity among them.This work was supported by EC PhageVet-P (contract no. FOOD-CT-2005-007224) and by the Russian Foundation for Basic Research (grant no. 08-04-00162-a). We gratefully acknowledge the support of organizations presenting the grants.info:eu-repo/semantics/publishedVersio

Localised genetic heterogeneity provides a novel mode of evolution in dsDNA phages

Abstract The Red Queen hypothesis posits that antagonistic co-evolution between interacting species results in recurrent natural selection via constant cycles of adaptation and counter-adaptation. Interactions such as these are at their most profound in host-parasite systems, with bacteria and their viruses providing the most intense of battlefields. Studies of bacteriophage evolution thus provide unparalleled insight into the remarkable elasticity of living entities. Here, we report a novel phenomenon underpinning the evolutionary trajectory of a group of dsDNA bacteriophages known as the phiKMVviruses. Employing deep next generation sequencing (NGS) analysis of nucleotide polymorphisms we discovered that this group of viruses generates enhanced intraspecies heterogeneity in their genomes. Our results show the localisation of variants to genes implicated in adsorption processes, as well as variation of the frequency and distribution of SNPs within and between members of the phiKMVviruses. We link error-prone DNA polymerase activity to the generation of variants. Critically, we show trans-activity of this phenomenon (the ability of a phiKMVvirus to dramatically increase genetic variability of a co-infecting phage), highlighting the potential of phages exhibiting such capabilities to influence the evolutionary path of other viruses on a global scale

Air ions and human environment

Conformity to hygienic air ion formula of working offices, classrooms and chemistry laboratory in which the work with volatile organic solvents are conducted, as well as to a city apartment and a country house is investigated. Concentration of air ions was measured using the counter «Sapphire 3М». Parameters of the air ionization: concentration of ions of both charges (N and N-, ions/cm3) and unipolarity coefficient (K = N/N-) were evaluated. The quantity of air ions did not correspond to sanitary and hygienic standards in all areas except of a country house. Additional artificial air ionization and ventilation in classrooms and chemistry laboratories offered to use

Development of an effective way to increase the biological activity of nicotinamide - a new strategy to protect against photoageing and skin neoplasia

The objective of this work is to demonstrate changes in properties and increase of biological activity of nicotinamide (NAM) substance for skin protectants activated by mechanical activation (MA). To assess the physical, chemical and biological properties of NAM were used biotesting by the Spirotox-method, direct and indirect optical methods (microscopy, laser diffraction), infrared spectroscopy, pH-metry. The results of the study showed an increase in biological activity, expressed in changes in the energy of activation of cell transition to the "dead cell" state on the example of biosensor Spirostomum ambiguum. Also we indicated an increase in the rate of the chemical process of dissolution of mechanoactivated molecular crystals of nicotinamide (NAM) expressed in the values of the first order rate constant. Mechanical activation at a high rate of NAM substance powder deformation has led to changes in physical, chemical and biological properties of the drug, which can be used in medicine to increase efficiency and reduce doses of pharmacotherapy. Keywords: nicotinamide (NAM), basal cell carcinoma (BCC), mechanical activation (MA), microscopy, laser diffraction, Spirotox method

D/H control of chemical kinetics in water solutions under low deuterium concentrations

Variations in the isotopic composition drastically changes properties of molecules. This also applies to H2O, one of the most indispensable substances on Earth. Here we investigated physical, chemical and biological characteristics of deuterium depleted water (0.5 mM HDO) compared to water with natural deuterium content (16 mM HDO) and heavy water D2O. Reaction systems of different organization levels were probed: molecular (galactose mutarotation), supramolecular (destabilase-lysozyme activity), two-phase heterogenic (suspension of slightly water-soluble active pharmaceutical ingredients), and living cells (unicellular biosensor S. ambigua lifespan). We have shown that the mutarotation rate constant for the L-galactose was 2-fold less than that for the D-isomer over the whole temperature range without dependence on HDO concentration in low values, whereas the first-order mutarotation kinetics was not observed for L-galactose in heavy water. Interestingly, the initial rate of lysozyme activity of destabilase-lysozyme increased two-fold in deuterium-depleted water whereas there was no activity change in heavy water. In suspension system, the dissolution kinetics of active pharmaceutical ingredients conformed with the normal kinetic isotope effect when kH/kD > 1. This confirms the important role of variations in the solvent (water) isotopic composition in the dissolution process acceleration. However, the most important isotope effect was observed in the living cells, where the rate constant for the processes of irreversible S. ambigua cell transition (from an active state to an immobilized state) increased up to 800 times under deuterium depletion. © 2018 Elsevier B.V