Vol. 48 No. 1 (233) (2014)

A convenient method for obtaining pyridine alkaloid cerpegin and its various new C-1 and N-5 derivatives in high yields has been developed. Starting enaminolactones, synthesized by means of various tertiary keto-alcohols, have been condensed with primary aliphatic, aromatic or heterocyclic amines for a pyridine cycle formation. Bromine derivatives of furo[3,4-c]pyridinenones are obtained as well.

The present paper endeavors to define operating parameters of the atomic absorption method of spectroscopy for quantitative determination of Chromium in crome ores, crome concentrates and tailings. A new method of preparing standard solutions (in combination with microwave acid digestion of standard samples) is proposed for designing calibration curves and explicating conditions of supplying acetylene gas mixture and nitrous oxide, which enhance the accuracy of results obtained from the quantitative determination of chromium.

Formation of complex between cobalt ion (Co²⁺) and isoleucine (Ile) with composition 1:1, which reveals itself as a model catalyst for decay of cumene hydroperoxide (ROOH) in the studied Co²⁺+Ile+ROOH+H₂O system, has been established by kinetic method. The kinetic equation of rate of catalytic decay of ROOH under the action of [Cо∙Ile]⁺ complex catalyst has been derived: W₀ = –d[ROOH]₀/dt = K_cat [Cо²⁺]₀[Ile]₀[ROOH]₀ = K_eff[ROOH]₀. Temperature dependence of the effective rate constant (K_eff=K_cat[Cо²⁺]₀[Ile]₀) of decay of ROOH in the interval 323–353 K is expressed by Arrhenius equation (E_eff in kJ/mol): K_eff = (2.50±0.02)108 exp[–67.0 ± 0.3/RT] min^-1.

Different activation parameters for the of tionin-thiocyanate ionic pair extraction process: enthalpy (∆H), entropy (∆S), Gibbs energy (∆G) changes; activation energy have been determined by means of spectrophotometric method (E_a).

hermal denaturing of human hemoglobin (HHb) in the presence of tannic acid (TA) was studied by fluorescence and UV/vis spectroscopy in 30–66°C temperature range. To study more detailed structural changes in HHb molecule caused by temperature rise in the presence of TA, the excitation/emission fluorescence (3D spectra) matrix method has been used. It has been shown, that the increase of temperature causes more pronounced structural changes in the flexible areas of protein containing aromatic amino acids than in the rigid α, β polypeptide chains. It was revealed that the presence of TA causes structural changes in HHb.

Macro- and microelement compositions of barberry (Berberus L.) and deaf nettle (Lamium Album L.) leaves, collected from the territory of Goris City (RA) by atomic absorbtion spectrophotometry method were studied. It was shown that the heavy metal (Hg, Pb, Cd and As) content values in the mentioned plant leaves do not exceed their maximum allowable concentrations (MAC).

The reversible rat liver arginase at low pH conditions was investigated. It is shown that after 12 h pH 3.6 enzyme inactivation is able to recover its activity at the presence of different factors. Due to hypoxia 2 protein fractions (molecular weight of 55650–71200 Da) were indused, which then were added to the reactivation medium. It is reported that the addition of these fractions leads to reactivation up to 72%. Therefore, it is possible that during our experiments low weight proteins have chaperon-like properties, which assist with folding process.

Qualitative analysis of fatty acids composition of mycelial extracts obtained from 18 species 30 strains of coprinoid mushrooms (CMs) from different clades (Coprinellus (C. bisporus, C. curtus, C. disseminatus, C. domesticus, C. ellisii, C. flocculosus, C. micaceus, C. aff. radians I, III, C. xanthothrix, C. sp.), Coprinopsis (C. cinerea, C. cothurnata, C. gonophylla, C. lagopides, C. maysoidispora, C. strossmayeri), Coprinus (C. comatus)), as well as not yet reclassified species Coprinus patouillardii was realized by Gas chromatographic analysis. Two unsaturated (lineolic, oleic) and three saturated (palmitic, stearic, myristic) fatty acids were detected in tested samples. Differences in fatty acid composition between clades from different families (Agaricaceae, Psathyrellaceae) were observed. All five fatty acids were detected in Coprinus clade (family Agaricaceae) in opposite to Coprinellus and Coprinopsis clades (family Psathyrellaceae).

Two enzymes of the ornithine cycle (ornitine carbamoyl transferase and arginase) activities and urea accumulation dynamics of being wood decaying and food product fungi Pleurotus ostreatus (Jacq.:Fr.) Kumm. during aging and developing different phases were investigated. Concomitant to fungi development and growth, arginase activity and positive dynamics of urea are connected for providing the corresponding level of osmotic pressure in hymenium.

In previous studies origin of human and ape chromosomes have been analyzed by comparative chromosome banding analysis and/or by fluorescence in situ hybridization (FISH). In the present study FISH-banding, i.e. multicolor banding using probes derived from Homo sapiens was applied to reanalyze the chromosomes of Thai southern pig-tailed macaque (Macaca nemestrina). The results agree with those of previous studies in other macaques, e.g. Macaca sylvanus. Thus, genetic differences leading to the observed large morphological differences within the Ceropithecoidae must be in the subchromosomal or even epigenetic level and have to be discovered yet.

The investigation of complexes of ethidium bromide (EtBr) and methylene blue (MB) with DNA at 0.02 M Na⁺ ionic strength of solution has been carried out. Absorption and differential absorption spectra of EtBr and MB and their complexes with DNA were obtained. The isobestic point was revealed on the absorption and differential absorption spectra of EtBr and its complexes with DNA, while on analogous spectra of MB and its complexes with DNA there is no isobestic point.

The genotoxicity of water pollution in Lake Sevan, near the Sevan peninsula, village Shorja and its basin (rivers the Gavaraget and the Dzknaget) was investigated. An assessment of DNA integrity in hemocytes of crayfish (Astacus leptodactylus) was performed using the Comet assay. The obtained results of DNA damage level of crayfishes from the aquatic environment near village Shorja, the Gavaraget and the Dzknaget Rivers demonstrate significantly higher levels than from the peninsula of Lake Sevan. The results suggest that crayfishes are sensitive test objects for ecotesting of natural water bodies.