ԵՊՀ Գիտական տեղեկագիր - քիմիա և կենսաբանություն

Kinetics of cumene hydroperoxide catalytic decay in aqueous solution in the presence of copper ion (II) and tryptophan

2019-08-22T08:34:25+00:00

The formation of Cu2+ : Tryptophan (Trp) = 1 : 1 complex, which acts as a model catalyst for decomposition of cumene hydroperoxide (ROOH) in H2O+Cu2++Trp+ROOH system, has been confirmed via kinetic study in aqueous solution at pH > 7. Kinetic equation of single catalytic decomposition reaction of ROOH under the influence of [CuTrp]+ complex was derived: W0= –d[ROOH]0/dt=Kcat[Cu2+]0[Trp]0[ROOH]0= Keff [ROOH]0. The temperature dependence of the effective rate constant Keff (Keff= =Kcat[Cu2+]0[Trp]0 = const) for ROOH decay in the temperature range from 323 to 343 K can be expressed by Arrhenius equation (Keff is in kJ/mol): Keff =(7.45 ± 0.02) ·106 exp[–(56.5 ± 0.2)/RT] 1/min.

Sorption of Co2+, Cu2+, Zn2+, Mn2+ metal ions from aqueous solutions on anionic surfactant-modified bentonite

2019-08-22T08:42:48+00:00

The sorption of Co2+, Cu2+, Zn2+ and Mn2+ metal ions on anionic surfactantmodified bentonite was studied. The optimal conditions for the effective sorption of Co2+, Cu2+, Zn2+ and Mn2+ metal ions from aqueous solution were obtained. It was established that sorption of studied metal ions on anionic surfactantmodified bentonite occurs both by ion-exchanging and adsorption mechanisms.

DNA protection from radiation damage

2019-08-22T08:48:24+00:00

The use of radioprotectors is important as one way to decrease radiationrelated deleterious effects on normal tissues. The aim of this research was to study the radioprotective abilities of the newly synthesized compounds such as Cu(II) complexes with tryptophan, histidine and phenylalanine. The rats were exposed to X-ray at 5 Gy dose (LD50/30) after preliminary administration of 10 mg/kg compounds. At 3, 7, 14 and 28 days following irradiation DNA was isolated from rats’ livers. In order to detect defects in the DNA structure on the specified days, the DNA melting parameters were determined, including the melting point, temperature interval of melting and hypochromic effect. The results showed that the Cu(II) complexes derived from tryptophan, histidine and phenylalanine exhibit radioprotective properties. The investigated compounds demonstrated positive effects on the melting parameters of liver DNA, testifying a preservation of the DNA secondary structure stability.

Тhe morphological observation of mycelia of several Armenian strains of medicinal bracket fungus Fomes fomentarius (L.) Fr. (Polyporales, Agaricomycetes) (Fomes fomentarius (L.) FR.

2019-08-22T09:01:36+00:00

The morphological and growth characteristics of several Armenian strains of the tinder polypore fungus Fomes fomentarius were screened on agar media at 25, 30, 35, 38°C and 40°C. The revealed taxonomically valuable mycelial characteristics can be used for identification of F. fomentarius, as well as to control the purity of cultures during their biotechnological cultivation to obtain biomass and bioactive compounds.

Morphological and growth characteristics of mycelial collections of medicinal xylotrophic mushrooms (Agaricomycetes) distributed in forests of Northern Iran

2019-08-22T10:39:22+00:00

The morphological and growth characteristics of mycelial cultures of 24 xylotrophic medicinal Agaricomycetes mushrooms including 12 edible species collected in Mazandaran and Golestan Provinces of Northern Iran were studied for the first time. The morphology of colonies, growth parameters, and an ability to develop in vitro teleomorph, presence and form of hyphal clamps, cystidia, loops, asexual spores (anamorphs), crystals and other cultural characteristics of Iranian collections were observed. The obtained data can be used for taxonomic identification of mycelial cultures of studied species/strains during their biotechnological cultivation to obtain mycelial biomass and bioactive compounds.

Hoechst 33258 compound interaction with different GC-content DNA

2019-08-22T11:56:54+00:00

The interaction of Hoechst 33258 (H33258) compound with different GC-content DNA has been studied using the melting method. The obtained data show that at low ionic strengths of the solution (~0.002 M) H33258 does not display specificity for DNA AT sequences. Moreover, the effect was revealed not to depend on DNA nucleotide sequence. It has been shown that the increase in the ionic strength by an order of magnitude results in the development of a pronounced specificity of H33258 for DNA AT-sequences. H33258 was also found to exhibit a higher affinity for DNA having a block structure.

Application of clove essential oil for correction of shifts in hemodynamic parameters in students induced by cycle ergometer exercise

2019-08-22T12:06:41+00:00

Shifts in some cardiac hemodynamic parameters were studied in students during a 15-minute cycle ergometer load attended with cold inhalation of clove essential oil. It is shown that the use of essential oil of cloves contributes to the alignment of shifts in the level of functional indicators of students, by increasing the adaptive capacity of the organism. Essential oil of cloves causes a decrease of “physiological cost” of physical activity performed by students by strengthening the economization processes of functional systems activity. Curing an increase in the sympathetic effects on the body, induced by physical activity, the oil of cloves contributes to the rapid restoration of the functional state of the body in the nearest post-load period. As a control, indicators of the functional state and cardiac hemodynamics of students who, during bicycle ergometer load, were not subjected to the corrective influence of the essential oil of cloves, were used.

The impact of Zangezur Copper and Molybdenum Combine activities on the pollution of agricultural lands and crops by toxic elements

2019-08-22T12:37:00+00:00

The aim of the study was to assess the pollution of agricultural lands and crops with some potentially toxic trace elements conditioned by the activities of Zangezur Copper and Molybdenum Combine, as well as an assessment of the risk level of the studied crops for human health. The study was implemented in 2018. It was revealed that the soils of agricultural land in the surroundings of the combine were polluted by some trace elements, in particular by copper, but the content of Cu in crops growing in this area did not exceed the maximum permissible concentrations (MPC). The exceeding of MPC was registered in case of Cd, Ni, Zn and Cr. The highest excess of toxic elements in vegetables was observed in garlic and above-ground parts of red beet, and in an apple among fruits. In this regard, it is essential to implement the soil renewal and remediation activities in the studied area, in particular, phytoremediation, which is considered to be a harmless and cost-effective approach to remove toxic pollutants.

Evaluation of functional effect of genes and their variants associated with schizophrenia

2019-08-22T12:49:11+00:00

Prediction of the functional role of the genetic variants in Schizophrenia (SCZ) using the bioinformatics toolkit showed that decreased levels of CPLX2 gene are associated with the rs1366116*Т allele and rs3892909*C alleles of the same gene. On the contrary, rs4940456 is not associated with changes in the CPLX4 expression level, but the other SNPs linked to it correlate with the increased expression of the LMAN1. Minor allele of rs1049171-linked SNP rs17106725*T is associated with the increased CRMP4 expression. The expression of the STK32A gene is also increased in patients with SCZ, though LD analysis did not reveal genetic variants linked to rs1049171. Thus, the carriage of rs1049171*G does not have any impact on the STK32A expression in SCZ. Finally, rs1366116 and rs3892909 of the CPLX2, rs4940456 of the CPLX4 and rs1049171 of the CRMP4 genes might be indirect markers for the gene expression changes in patients with SCZ.

Application of the vector рЕС-ХК99Е for the construction of recombinant strain-producers of L-arginine based on Brevibacterium flavum

2019-08-22T13:17:28+00:00

Using Escherichia coli – Corynebacterium glutamicum shuttle expression vector pEC-XK99E, molecular cloning of the heterologous gene argJ of the thermophilic bacterium Geobacillus stearothermophilus, as well as of homologous genes argG and argH of Corynebacterium glutamicum was carried out in cells of coryneform bacterium Brevibacterium flavum. It was shown that expression of cloned arg genes from the strong promoter Ptrc (its activity is controlled by the protein repressor LacIq ) occurred regardless of the presence of transcription inducers lactose or IPTG in the medium.

Summary

2019-08-22T13:19:47+00:00