Purification of nerve growth factor from the venom of the Central Asian cobraNaja oxiana

A highly purified electrophoreticaly homogeneous protein with a NGF activity of 10·10⁵ BU/mg of protein have been isolated from the venom of the Central Asian cobra by gel-filtration and ion-exchange chromatography followed by preparative isolectric focusing in a thin layer of Sephadex. It has been shown that the NGF isolated is characterized by a molecular weight in the range of 20–30 kD and a pI value of about 7.0.     

Radiation dose assessment for137Cs from fish in the Aegean Sea before and after the Chernobyl accident

The effective doses from fish in the Aegean Sea have been calculated for the nuclide¹³⁷Cs covering the period 1975–1982. The effective dose varies between 3×10^–5 and 10×10^–5 mSv y^–1 for adults and 14×10^–5 to 56×10^–5 mSv y^–1 for children, while the cumulative effective dose for the period 1975–1982 equals to 40.86×10^–5 and 229.57×10^–5 for both adults and children of 10 y old, respectively. When compared to doses derived from the Chernobyl accident /May 1986/ it was found that the additional dose incurred by Greek individuals in May 1986 was approximately equal to the cumulative dose of 8 y contribution period /1975–1982/ for adults and to a year's contribution for children of 10 y old.     

Interaction of pectin substances with copper,mercury, zinc,and cadmium salts

The interaction of the sage, mint, apple, and ginseng pectins, isolated from tissue culture wastes and purified with copper, mercury, zinc, and cadmium salts, has been studied by the amperometric method with two metal indicator electrodes. The optimum conditions of titration have been determined: pH 3.5–5.0; concentration of pectin substances 5·10^–5-1·10^–3 g/ml of solution. It has been established by graphical and mathematical methods that the interaction is accompanied by the formation of compounds with a ratio of the carboxy groups of pectins to the metal cation of two. The IR spectra of sage pectin and of copper and mercury pectinates are given.M. V. Frunze, Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 171–175, March–April, 1988.     

Investigation of the complex formation of technetium with thiourea by spectrophotometry and electromigration

TcO ₄ ^– is reduced by thiourea /tu/ to Tc/III/ in 6N HCl. By capillar electrophoresis three different cations have been identified with electrophoretic mobilities of u=/4.3–4.8/x10^–4 u=/3.2–3.8/x10^–4, and u=/2.2–2.8/x10^–4 cm² v^–1s^–1. These species were assigned to complex cations [Tc/tu/₆]³⁺, [Tc/tu/₅Cl]²⁺, and [Tc/tu/₄Cl₂]⁺, respectively. [Tc/tu/₆]³⁺ was identified by spectrophotometry according to recently published data. [Tc/tu/₅Cl]²⁺ was isolated and chemically characterized. The formation of the monovalent cation [Tc/tu/₅Cl₂]⁺ was concluded from spectrophotometrical measurements.     

Immobilization of Urease and Cholinesterase on the Surface of Semiconductor Transducer for the Development of Light-Addressable Potentiometric Sensors

Various methods for the immobilization of urease and butyrylcholinesterase on the insulator surface of a laser-scanned semiconductor transducer (LSST) have been tested and compared for the development of an enzyme-based light-addressable potentiometric sensor (LAPS). The method of preparing photocurable membranes on LAPS is presented, and a new type of enzyme LAPS with photocurable polymeric enzyme membranes has been elaborated. It was found that sensors prepared by means of covalent bonding and cross-linking with inactive protein (type SIII) and with photocurable membrane matrices (type SIV) are more prospective. The enzyme LAPSensors with photocurable membranes demonstrate a degree of sensitivity close to the theoretical value and working ranges of 6.3·10^–5–1.1·10^–2 and 1·10^–4–1·10^–1molL^–1 urea for acrylamide and acrylate-based membrane matrices, respectively, and 2.5·10^–4–2·10^–1molL^–1 butyrylcholine for an acrylamide membrane matrix. It is shown that such sensors can be also used for the analysis of enzyme inhibitors.     

Polarographic and voltammetric determination of trace amounts of 2-nitronaphthalene

The polarographic behaviour of 2-nitronaphthalene was investigated by DC tast polarography (DCTP) and differential pulse polarography (DPP), both at a dropping mercury electrode, and differential pulse voltammetry and adsorptive stripping voltammetry, both at a hanging mercury drop electrode. Optimum conditions have been found for the determination of 2-nitronaphthalene by the given methods in the concentration ranges of 2×10^–6–1×10^–4, 2×10^–7–1×10^–4, 1×10^–8–1×10^–4 and 2×10^–9–1×10^–8 M, respectively. Practical applicability of these techniques was demonstrated by the determination of 2-nitronaphthalene in drinking and river water after its preliminary separation and preconcentration using liquid–liquid and solid-phase extraction with limits of determination of 3×10^–10 M (drinking water) and 3×10^–9 M (river water).     

On the characteristics and mechanism of the radiation-induced chain reaction between sulfur dioxide and molecular oxygen in acid solutions

Characteristics of the -induced chain reaction between sulfur dioxide and molecular oxygen in perchloric and sulfuric acid media in the presence of Ce(III) ions have been studied. The concentration effects of dissolved oxygen (0.2·10^–3–9.4·10^–3 mol/dm³, sulfur dioxide (0.3·10^–1–2.0·10^–1 mol/dm³ and Ce(III) (0.2·10^–3–4.8·10^–3 mol/dm³) and dose rate (0.26·10¹⁹–1.0·10¹⁹ eV/dm³·s) on the radiation — chemical yield of oxygen consumption G(–O₂) and accumulation of sulfate G(HSO ₄ ^– ), have been investigated. The reaction proceeds with G(–O₂) reaching 10²–10³ molecule/100eV in a catalytic regime. The reaction rate in perchloric acid medium is 3–4 times lower than that in the sulfuric acid medium and depends on the SO₂, O₂ and Ce(III) concentrations, the reaction order varying from 1.0 to 0 and/or in the reverse direction. The mechanism of the process involves chain propagation with 3 stages and 3 intermediates: SO₃H, HSO₅ and Ce(IV). The catalytic effect is caused by the interaction of HSO₄ with Ce(IV) ions followed by their reduction when interacting with SO₂, yielding SO₃H radicals. Chain termination may be due to one or two of the three intermediates or due to all three particles, the kinetics depending on this. Kinetic equations describing the experimental data have been obtained.     

Rapid determination of telmisartan in pharmaceuticals and serum by the parallel catalytic hydrogen wave method

The polarographic characteristics of telmisartan have been investigated in 0.8 mol L^–1 NH₃.H₂O–NH₄Cl (pH 8.9)–0.01 mol L^–1 H₂O₂ as supporting electrolyte. The results demonstrate that the polarographic reduction wave at ca. –1.30 V in the absence of H₂O₂ is a catalytic hydrogen wave, and the reduction wave enhanced by H₂O₂ is a so-called parallel catalytic hydrogen wave. The analytical sensitivity of the parallel catalytic hydrogen wave is ca. 60 times higher than that of the corresponding catalytic hydrogen wave. Based on the parallel catalytic hydrogen wave a novel method has been developed for determination of telmisartan by linear sweep polarography. The calibration curve is linear in the range 2.0×10^–8–2.0×10^–6 mol L^–1 and the detection limit is 1.0×10^–8 mol L^–1. The precision is excellent with relative standard deviations of 2.6% at a concentration of 1.0×10^–7 mol L^–1 telmisartan. The proposed method has been applied to the direct determination of the telmisartan in capsule forms and biological samples. The proposed method has been proved to be advantageous over existing CZE and MEKC methods in simplicity, rapidity, and reproducibility.     

Influence of the glycoproteins of the cotton plant on the biosynthesis of proteins and nucleic acids

An inhibitory action of ELPs and LLPs on the inclusion of³H-thymine and³⁵S-methionine in the cells of a suspension culture and isolated nuclei of cottonplant seedlings has been found. The influence of the ELPs on the proliferative activity of cottonplant cells and of the ELPs and LLPs at the level of protein biosynthesis in isolated nuclei bears a dose-dependent nature, in contrast to the galactose-specific fraction LLP-1.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 62 70 71. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 865–870, November–December, 1997.     

NMR study of alkaloids. V.13C NMR spectra and reconsideration of the structures of 11- and 10-hydroxypleiocarpamines and the structures of new alkaloids fromVinca erecta

The structures of phenolic alkaloids isolated previously fromVinca erecta Rgl. et Schmalh. have been reconsidered on the basis of the results of a study of their¹³C NMR spectra, and it has been shown that a base with mp 228–229° has the structure of 11-hydroxystrictamine and an amorphous base of the same composition isomeric with it is 10-hydroxystrictamine. The structures of two new indolenine alkaloids — ercinamine and ercinaminine — have been determined from an analysis of¹³C NMR spectra, and also on the basis of PMR and IR spectra and chemical transformations.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 483–488, July–August, 1983.     

Rapid radiochemical separation and determination of chlorine,bromine and iodine in water samples using ion exchange

On the basis of tracer experiments, a simple and rapid radiochemical separation method for simultaneous determination of I^–, Br^– and Cl^– in one aliquot of a water sample (only 2–4 ml) has been developed. The method is based on short irradiation of the water sample and separation of the halogens using sequential ion exchange columns filled with Dowex 1×8, 100–200 mesh anionic resin prepared in I^–/I₂, Br^–/Br₂ and Cl^– form. After washing the columns with an appropriate volume of 2% NaCl solution, the resins were transferred to vials and activities of the isolated radionuclides¹²⁸I,⁸²Br and³⁸Cl measured together with standards in a well type or on a coaxial Ge detector connected to a Canberra 90 multichannel analyzer. Besides high chemical yields, from the -spectra of the isolated radionuclides, it is evident that high decontamination fac-The paper was presented at the MTAA-8, Vienna, September 1991.     

Isolation and characterization of phytokinin-binding proteins from the cotton plant

A highly purified site of a cytokinin-binding protein with a K_D value for³H-BAP of 4.3 nM has been isolated from cotton-plant seedlings by the methods of biospecific and hydrophobic chromatography. According to the results of electrophoretic analysis under denaturing conditions its molecular mass is 43 kDa.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbekestan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 702–706, November–December, 1992.     

Protein kinase from cotton seeds

A Ca²⁺-dependent protein kinase C, active at pH 6.5–8.0 has been found in cotton seeds for the first time. The localization of the enzyme in the seeds has been established and some of its properties are described (stability in various media, capacity for performing the phosphorylation of various substrates, activation by calcium ions). Highly active preparations of cottonseed protein kinase C have been isolated by biospecific chromatography.Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 255–259, March–April, 1989.     

Solubility of Solid 2,3-Dimethylbutane and Cyclopentane in Liquid Argon and Nitrogen at the Standard Boiling Points of the Solvents

The solubilities of solid 2,3-dimethylbutane and cyclopentene in liquid argon at a temperature of 87.3 K and in liquid nitrogen at 77.4 K have been measured by the filtration method. The hydrocarbon contents in solutions were determined using gas chromatography. GC–MS was used to identify impurities in solutes. The experimental value of the mole fraction solubility of solid 2,3-dimethyl-butane in liquid argon at 87.3 K is (8.26 ± 1.60) × 10^–6 and (2.77 ± 0.94) × 10^–8 in liquid nitrogen at 77.4 K. The experimental value of the mole fraction solubility of solid cyclopentene in liquid argon at 87.3 K is (5.11 ± 0.44) × 10^–6 and (4.60 ± 0.76) × 10^–8 in liquid nitrogen at 77.4 K. The Preston–Prausnitz method was used for calculation of the solubilities of solid hydrocarbons in liquid argon in the temperature range 84.0–110.0 K and in liquid nitrogen from 64.0 to 90.0 K. The solvent–solute interaction parameters l ₁₂ were also calculated. At 90.0 K liquid argon is a better solvent for investigated solid hydrocarbons than is liquid nitrogen.     

The behaviour of plutonium in aqueous basic media

Behaviour of Pu(IV) and Pu(VI) in basic media has been investigated by studying their stabilities and quantitative determination by spectrophotometry. Beer's law was found to be obeyed in the range of 1·10^–3 to 5·10^–3 M Pu(IV) at 485 nm peak with a molar absorption coefficient of 95M^–1· cm^–1 in sodium carbonate medium. In case of Pu(VI), in the same medium Beer's law was obeyed in the concentration range of 2·10^–3 to 1·10^–2M at 550 nm with a molar absorption coefficient of 50M^–1·cm^–1. Distribution ratios of Pu(IV) and Pu(VI) for their sorption on Al₂O₃ and Amberlyst A-26 (MP) resin from bicarbonate and carbonate media have been determined. High distribution ratios obtained indicate the feasibility of decreasing the plutonium content of basic carbonate streams in reprocessing. 10% breakthrough capacities for Pu(IV) and Pu(VI) with these exchangers during column operations have also been determined.     

The electrochemistry and determination of Ligustrazine hydrochloride

Ligustrazine is one of the active ingredients contained in Ligusticum chuanxiong Hort. (Umbelliferae), which is widely used in traditional Chinese medicine for the treatment of cardiovascular problems. In this work, the electrochemistry of Ligustrazine hydrochloride (LZC) and its determination are investigated. The detection limit is estimated to be 8.0×10^–8 M, with three linear ranges from 1.0×10^–6 to 1.0×10^–4 M, 1.0×10^–4 to 5.0×10^–4 M, and 6.5×10^–4 to 1.6×10^–3 M. The method has been proved to be highly sensitive, selective, and stable, and has been successfully applied to determining LZC in LZC injections.     

The effect of high pressure on the ion pair equilibrium constant of alkali metal fluorides: A spectrophotometric study

Bromophenol blue indicator was used in UV-visible spectrophotometric measurements to study ion association constants of alkali metal fluorides. The equilibrium constants for the ion pair formation of the alkali metal fluorides were determined as a function of ionic strength at one atmosphere pressure and 25°C. The effect of pressure on these association constants was measured at a constant total ionic strength of 1.0 mol-kg^–1 over a pressure range of 1 to 2000 atmospheres at 25°C. The pressure dependences of the stoichiometric association constants of the alkali metal fluorides are given by: lnK _LiF ^* =0.77–2.47×10^–4P–2.12×10^–8P²; lnK _NaF ^* =0.53–1.08×10^–4P–1.66×10^–8P²; lnK _KF ^* =0.24–4.41×10^–5P–7.15×10^–8P²; lnK _RbF ^* =–0.17–8.65×10^–5P–4.51×10^–8P²; and lnK _CsF ^* = –0.37–1.14×10^–4P–6.82×10^–8P², where P is the pressure in atmospheres. The stoichiometric molar volume and compressibility changes for ion pair formation of the alkali metal fluorides were evaluated from the pressure dependence of K _MF ^* data. The thermodynamic association constants were also calculated making use of activity coefficient data from the Pitzer equations. The partial molal volume and compressibility changes for ion pair formation of each alkali metal fluoride are reported.     

Bradykinin-potentiating peptide from venom of the spider Latrodectus tredecimguttatus

A bradykinin-potentiating peptide has been isolated from the venom of the spiderLatrodectus tredecimguttatus. Its physicochemical properties and amino acid composition have been investigated in detail. It has been shown by biological testing on isolated neck of the rat uterus that the peptide increases the contractile effect of bradykinin in in vitro experiments. The potentiating unit is 2 · 10^–3 mg/ml. A 50% increase in the hypotensive effect of bradykinin at a concentration of the bradykinin-potentiating peptide of 15 µg/kg of body weight has been found, the increase in the intensity of the effect being accompanied by a prolongation of its action.A. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 699–703, September–October, 1989.     

Alpha-recoil atoms of plutonium in the environment

The -recoil effect of²³⁹Pu has been observed in environmental samples and theN ₅ ^P /N₅ ratio in these samples has been calculated. This ratio in atmospheric samples is in the range between 10^–5 and 10^–4 (atom/atom). For other contemporary terrestrial samples it is in the range between 10^–7 and 10^–6 (atom/atom), while that of uranium mineral is about 10^–10 (atom/atom). The results further explain the radioactive fallout contamination of our environment by uranium and plutonium isotopes.     

Electrochemical Study of Iodide in the Presence of Barbituric Acid: Application to the Catalytic Determination of Barbituric Acid

Electrochemical oxidation of iodide has been studied in the presence of barbituric acid using cyclic voltammetry and controlled-potential coulometry. The results indicate that the barbituric acid participating in the halogenation reaction converts to an iodo derivative of the parent compound. Moreover, the results are indicative of the suitability of iodide as a mediator for the determination of barbituric acid in aqueous solutions. The quasicatalytic peak current is linearly dependent on the barbituric acid concentration. The calibration graph is parabolic, with two linear sections of 6.0 × 10^–5–1.0 × 10^–3and 1.0 × 10^–3–1.0 × 10^–2M. The relative standard deviation for ten determinations of 2.0 × 10^–4M barbituric acid is 2.1%, and the detection limit of the method is 3.97 × 10^–5M.