Vol. 54 No. 3 (253) (2020)

The esterification of sucrose with stearic, palmitic and oleic acids yields the corresponding esters. Effective methods have been developed for carrying out the esterification reaction at temperatures of 150–170℃ in high-boiling aprotic dipolar solvents.

On the basis of cyclic esters а method for producing of γ-hydroxybutyric acids hydrazides has been elaborated. The antioxidant properties of hydrazides were researched by the method of competitive reactions and it was established that they have antioxidant activity.

The Agaricomycetes mushrooms (phylum Basidiomycota) are recognised sources of valuable food and medicines. They are producers of bioactive compounds (phenolics, polysaccharides, proteins, steroids, terpenoids, etc.) possessing around 130 therapeutic effects (antimicrobial, anti-inflammatory, antioxidant, immunomodulatory, etc.). Mushrooms are also reported as potential neurotrophic and neuroprotective agents. Seventeen edible and inedible agaricomycetous species from different taxonomic and ecological groups have been reported in Armenia to possess neuroprotective activity. Evaluation resource value and biotechnological potential of Armenian agaricomycetous mushrooms will assist further development of novel myco-pharmaceuticals to prevent and mitigate different disorders, including neurodegenerative.

The interaction of Hoechst 33258 (H33258) and methylene blue (MB) compounds with bovine serum albumin (BSA) has been studied using the method of thermal denaturation. The obtained data showed that both ligands form complexes with BSA, moreover, MB binds to BSA stronger than H33258. Furthermore, H33258 destabilizes, while MB stabilizes the native structure of protein, leading to the decrease and increase of the denaturation temperature of BSA respectively.

The effect of millimeter range electromagnetic waves (MM EMW) on kinetics of acidic hemolysis of rat blood erythrocytes has been studied. It was shown that MM EMW affect the duration of erythrocyte hemolysis and this change depends on MM EMW exposure and frequency. At the irradiation by frequencies 41.8 and 42.2 GHz the acidic hemolysis occurs quicker at all durations of the irradiation compared to the control. At the irradiation by 50.3 and 51.8 GHz the hemolysis takes place quicker as well, as compared to the control at short durations of the irradiation. At the exposure 60 min the hemolysis start is delayed.

Cell redox homeostasis is formed as a result of the balance between the accumulation of reactive oxygen species and functioning of the antioxidant enzymes or non-enzymatic antioxidants. The alcohol extracts from the leaves of Ribes nigrum L. were prepared to investigate the antioxidant activity and protective effects against both BV-2 microglial wild type (WT) cells and acyl-CoA oxidase type 1 (ACOX1) deficient cell (ACOX1^–/–) lines․ Our investigations showed that R. nigrum extracts possess remarkable antiradical activity in 1-diphenyl-2-picryl­hydrazyl (DPPH) with IC₅₀ value of 32.7±0.8 µg·mL^–1. 3-(4,5-dimethyltrazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the sub-cytotoxic concentration of R. nigrum extract in both cases was 1 mg·mL^–1. The further treatment of microglial cells with the mentioned concentration of extract brought the remarkable increasing (up to 350%) of activity of the total superoxide dismutase (SOD) – the core antioxidant enzymes, under the treatment during the 48–72 h. So, relaying on the obtained data it is possible to insist that the lack of ACOX1 can be compensated by the activation of cell enzymatic antioxidant defense mechanisms.

Using the “Bioscope” hardware complex, it was shown that an oxygen deficiency leads to certain changes in the statistical parameters of the integrative state of animals both during and after hypoxia exposure. However, after 10 days of using horseradish roots (Armoracia rusticana) as an antihypoxic food supplement, in contrast to the control, significant changes in the recorded signal are observed both during and after hypoxic exposure. These changes indicate the facilitating effect of horseradish roots in conditions of oxygen deficiency.

Rich in natural antioxidants, Stevia rebaudiana has immunoregulatory, anti-stress, anti-inflammatory, antiviral, antihistaminic properties, increases the body's nonspecific defense, bioenergetic level, and improves tissue respiration. We have studied the long-term effect of S. rebaudiana on morphofunctional parameters of peripheral blood.

The aim of this study was to define a relationship between heavy metal (Cu, Mo) pollution of soil and various extracellular enzyme activities. Six enzymatic activities involved in cycles of carbon, nitrogen, phosphorus and sulfur (β-glucosidase, chitinase, leucine-aminopeptidase, acid phosphomonoesterase, alkaline phosphomonoesterase, and arylsulphatase) as well as microbial biomass were determined in soil samples collected in the surroundings of Zangezur Copper and Molybdenum Combine. The investigations showed that pollution of soil with copper and molybdenum led to a decrease in microbial biomass and soil enzymatic activity, which in turn had a negative impact on cycles of chemical elements, in particular C, P, N and S. This gives reason to conclude that the changes in soil microbial biomass and enzymatic activity may act as indicators of soil biological activity and quality.

An assessment of the ecological state of the Voghji River and its catchment basin according to chemical and biological indicators in the period 2018–2019. New taxa were discovered in phytoplankton, when contaminated with heavy metals and organic substances. A decrease in community stability and an increase in the role of Сyanoprokaryotes and green algae in plankton were observed, which can be used for phytoremediation of the degraded ecosystem of the Voghji River.

Hydrochemical investigations in the Hrazdan River, Armenia, were conducted. Water samples for pH, EC, K⁺, Ca²⁺, SO₄^2-, Mg²⁺, Cr⁶⁺, Fe, and Zn analyses were taken from the river midstream in May and July 2019 and the downstream in June, August, and September 2020. The results of this study revealed the current hydrochemical status of the Hrazdan River, as well as the ecological and agorecological risks and potential sources of hydrochemical pollution in the river ecosystem.

The interaction of methyl violet (MV) with human serum albumin (HSA) has been studied, using the fluorescence spectroscopy method. It was shown that MV chnages the own fluorescence of HSA. It was also shown that MV does not induce any conformational change in the structure of HSA, since there is no change of the wavelength of HSA fluorescence intensity maximum. MV binds to HSA, near to fluorescing tryptophan, which in the hydrophilic environment, and changes the own fluorescence of the protein.