Vol. 39 No. 1 (206) (2005)

The antioxidant properties of dimethylsulphoxide (DMSO), diethylsulphoxide (DESO) and dipropylsulphoxide (DPSO) in methanol, CCl₄ and acetonitrile with the use of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical have been investigated by spectrophotometric method. It has been shown that the antioxidant properties of dialkylsulphoxides depend on the polarity of the solvent, which is more expressed in the case of DPSO.

It has been established that in the temperature range 298–308 K in presence of cationic and anionic surfactants the rate of the reaction (R_r) H₂O₂+HOO^– depends on the [S]₀ by bell-shape curve. Wr has minimum value at [S]₀ =ccm. At [S]₀ >ccm in the system micelles are formed, which are more favorable medium for the reaction. Depending on the ratio of both S initial concentrations their mixtures show different calloid-chemical proporties. It is shown that R_r depends on them. The inverse w/oil micelles are more favorable medium for the studied reaction than the oil/w type direct micelles.

Intermolecular interactions of p-toluidine in polar (aprotonic and protic) and non-polar solvents have been investigated by UV/vis and fluorescence spectroscopy methods. The influence of the solvent on p-toluidine spectra is discussed on the basis of Lippert equation. It has been revealed that in the ground state p-toluidine forms hydrogen bonds with protic solvents, acting as a proton acceptor. In the excited state with these solvents p-toluidine forms additional hydrogen bonds due to the negative site of the aromatic ring.

The interaction of aqueous solutions of L-Lysine (Lys) with various acids is studied with the aim of obtaining new crystalline salts displaying nonlinear optical (NLO) properties. A series of new salts from the systems: Lys+HF+H₂O, Lys+HBF₄+H₂O, Lys+HClO₄+H₂O, Lys+HNO₃+H₂O, Lys+HCOOH+H₂O and Lys+H₂C₂O₄+H₂O is obtained and identified by IR spectroscopy. Thermal properties were investigated. Second harmonic generation signals of YAG:Nd³⁺ laser are observed in some crystals.

Rhodium(III) interacts with acridine yellow in hydrochloric acid solutions. The formed ion associate could be extracted by the dychlorethan–carbon tetrachloride (2.5+2.5) binary mixture, maximal extinction is observed at the value of wavelength 460 nm. Optimal acidity of aquans solutions is pH 2.0 by HCl. The optimal quantity of dye is 1.0–2.0 mL of 0,05% solutions. The coefficient of extraction is 92.6%. The range of determined concentration is 0.73–14.63 mcg of Rh(III) in 10 mL of aqueous phase. The value of seeming coefficient of acridine yellow tetrachlorrhodiate (III) ionic associates organic extracts molar extinction ε = 3.5·10⁴ L·mol^-1·cm^-1. The molar ratio beetwin acridine cation and tetrachlorrhodiate (III) is 1:1.

It has been treated the method of synthesis 2-acetyl(cyano-, ethoxycarbonyl-)-3-methyl-4,4-dialkyl-2-butene-4-olides by interaction of tertiary α-ketoalcohols with compounds containing the active methylen group in the presence of sodium methylat in absolute methanol environment at room temperature.

Using the helfiltration and ionic exchange chromatography methods the total saltsoluble protein of mutant seeds of Armenian red bean induced with ethylenimyne has been studied. It has been found that certain qualitative and quantitative changes has taken place in the protein of mutant seeds.

Effects of different lead concentrations on induction of chlorophyll a fluorescence were studied in Chlorella and Spirulina. Beginning with concentration of 12.5 mL/L falling of parameters of induction curve was observed. The change of these parameters indicates decrease of activity of PS II. It is also shown, that Spirulina is steadier in presence of lead in the environment, than Chlorella.

The article gives facts about forage crops’ dangerous fungal diseases, which are more spread in Armenia. Are pointed more dangerous types of fungi, which are adapted to those plants’ certain genera, are pointed out steady tips to pathogens.

Literature data about several debatable questions on present classification of coprinoid mushrooms are discussed. Phylogenetical studies with using molecular methods of genetic analysis of the restriction site DNA, brought out polyphyletics of the traditional genus Coprinus. As a result, the species of genus Coprinus are suggested to divide into four genera (clades) which refer to two families: Agaricaceae and Psathyrellaceae. The family Agaricaceae includes the genus Coprinus s. str., with type species C. comatus, and family Psathyrellaceae: genera Coprinellus, Coprinopsis and Parasola, as well as newly studied species of genera Psathyrella, Lacrymaria Pat. and the main part of former coprinoid mushrooms.

The distribution of mesophilic and extremophilic bacilli in Lake Sevan water and silt, as well as in artesian and subsoil waters from boreholes at the Dzknaget River estuary was studied. New cultures of extremophilic bacilli, including thermophilic, alcalophilic, halophilic and psichrophilic forms, were isolated.

The article is based on expediency of using the cyanic bacterium in struggle against the soil erosion and reducing the degradated soils in RA. Some results of laboratorial researches and arrangements for realization the experimental project are discussed.

Interaction between palladium(II) and phenylthiourea (PTU) has been studied by means of potentiometry and amperometry methods. It has been shown that the molar ratio between acting components Pd(II) : PTU=l : 4. Conditions optimal for proceeding of electrode and chemical reactions in hydrochloric and sulfuric acids media have been estimated. The method of the amperometric determination of palladium(II) has been applied for its determination in the palladium-plating electrolyte.

The reaction of 2,5-diacetyl-3-(p-tolyl)-5-etoxycarbonyl-3-penten-4-olides with aromatic primary amines has been studied. It has been established, that l,4-diaryl-3-(1'-arylimino)ethyI-5-hydroxy-5-(1'-arylaminocarbonyl-2'-arylimino)propylpyrrolidones-2 are obtained by boiling the reactionary mixture in dimethylformamide.

The study of the influence of double-strand RNA (ds-RNA) on genetic transformation and conjugation processes has been carried out in a wide range of gramnegative bacteria species. It has been shown that ds-RNA in the presence of CaCl₂ in 10 µg/mL and 1 mM concentrations respectively efficiently increases the frequency of genetic exchange. The above mentioned concentrations of only ds-RNA or CaCl₂ separately don’t cause the same effect.

Damage of activity of the photosynthetic apparatus of a bean (Phaselus vulgaris) is investigated at positive (+50°C) and negative (-10°C) temperatures before and after influence of ammonia. It is established, that under specified condition the content of chlorophylls a and b decrease. Also their ratio (Chi a/Chi b) is broken. Change of sequence of influence of physical and chemical factors in activity of a pigment-protein complex of thylakoid membranes of the photosynthetic apparatus is differently reflected.