Action of cottonplant glycoproteins on the proliferative activity of cells

A mitogenic action of the total (LLPs) and lactose-specific (LLPs-1) lectin-like proteins on the proliferation of lymphocytes and of myeloma cells in culture has been found. A dose-dependent influence of the LLPs and extensin-like proteins (ELPs) on the inclusion of³H proteins in the myeloma cells, including an antimitotic effect of the ELPs with an increase in the protein dose, has been shown; the ELPs exert an analogous action on K–562 tumor cells of human erythroblasts. The nature of the biological action of the LLPs and ELPs is discussed in connection with features of the structure of the carbohydrate fragments of the composition of the glycoproteins.A. S. Sadykov Institute of Bioorganic Chemistry of the Academy of Sciences, Republic of Uzbekistan, Tashkent, fax (3712) 62 70 71. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 912–915, November–December, 1996. Original article submitted May 20, 1996.     

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.     

Synthesis, structure, and action of some gossypol derivatives on the peroxidation of the lipids of biosubstrates

The synthesis has been effected of new gossypol derivatives using piperidino-and morpholinoethylamines. According to their PMR spectra, these substances exist in the keto-amine form. Their action on the peroxidation of lipids (POL) of various biosubstrates has been studied. Gossypol bis(piperinoethylimine) and bis(morpholinoethylimine) in concentrations of 1·10^–7–5·10^–6 mM exert a pronounced antioxidant action on human blood serum and rat brain synaptosomes. In the same concentrations, these substances suppressed the POL in enzymatic and nonenzymatic systems of the oxidation of rat liver microsomes.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Institute of Hematology and Blood Transfusion, Ministry of Health of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 707–712, September–October, 1989.     

Metabolites of the pathogenic fungusVerticillium dahliae VIII. Interaction of the phytotoxic metabolite PKZh-1 with Na+,K+-ATPase

Summary It has been established that the phototoxic metabolite PKZh-1 of the fungusV. dahliae and, to a smaller extent, its chromophoric moiety possess an inhibiting action on the Na⁺,K⁺-ATPase of the microsomal fraction of the cells of the root hairs of the cotton plant of variety 108-F.The absence of specificity in the action of the phytotoxin has been shown in experiments on the Na⁺,K⁺-ATPase of the microsomal fractions of the cells of the cerebral cortexes of the ox, rat, and frog, bovine kidney, and tarantula ganglion.V. I. Lenin Tashkent State University. Institute of Biochemistry of the Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 59–62, January–February, 1979.     

Formation of ozonides of the alkaline-earth metals by the reaction of ozone with the hydroxides

Conclusions It has been shown by the EPR method that the colored products formed by the action of a mixture of ozone and oxygen on the solid hydroxides of the alkaline-earth metals are ozonides containing the molecular paramagnetic ion O₃ ^–.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 416–417, February, 1967.     

Inhibition of transport (Na+, K+)-ATPase by cardenolides of the strophanthidin group and a study of the structure-activity relationship

Summary A comparative study of the inhibiting action on transport (Na⁺,K⁺)-ATPase of 15 derivatives of strophanthidin and four rhamnosides of other aglycones have been made on the microsomal fraction of the cells of the rat cerebral cortex.It has been shown that the method of determining the activity of cardiotonic substances by determining the lethal dose and the enzyme test give completely comparable results. Both biological methods objectively reflect the characteristic features of the chemical structure of the cardenolides.Institute of Biochemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 188–194, March–April, 1976.     

Investigation of complexes of DNA with synthetic peptide fragments of the N-end of histone H2B

The nature of the interaction of high- and low-molecular-weight DNAs (6×10⁶ and 3×10⁵ daltons) with synthetic oligopeptides of the N-end of histone H2B having the sequences 1–21, 1–10, 1–13, 11–21, and 14–21, differing in molecular weight and amino acid composition, as a function of the amount of peptide component in the complex and the ionic strength of the solution has been studied by the methods of UV and CD spectroscopy and the spectrophotometric analysis of melting curves. It has been shown that of all the peptides studied only the 1–21 peptide possesses the capacity of condensing DNA. This capacity depends on the amount of peptide component in the complex, the molecular weight of the DNA, and the ionic strength of the solution. The interaction with peptides under all the conditions studied, without changing the conformational parameters of the DNA, stabilizes its secondary structure in relation to the action of the temperature, which depends on the number of lysine residues in the peptides.N. I. Nikitin Institute of Chemistry of the TadzhSSR Academy of Sciences, Dushanbe. Institute of Cytology of the USSR Academy of Sciences, Leningrad. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 708–713, September–October, 1987.     

Cationic polymerization of hydrocarbon monomers under the action of acyl halide complexes with Lewis acids

Polymerization of isobutylene in hexane at –78 °C under the action of the complex AcBr · 2AlBr₃ (Ac-2) affords polyisobutylene having C=O groups at the head and C-Br or C=C groups at the tail of all the molecules. The presence of the latter indicates that there occurs proton elimination from the growing carbocation with the formation of a superacid HBr · 2AlBr₃ which is unable to initiate the polymerization repeatedly under given contitions. This makes it possible to consider proton elimination as the reaction of the decay of active centers with the rate constantk _d. This value has been calculated from the rate of accumulation of the polymeric molecules having terminal C=C bonds:k _d=3.5 · 10^–4 s^–1. The rate constant of chain growthk _g has been determined from polymerization kinetics and from the content of active centers:k _g=6.2 L mol^–1 s^–1.For part 3, see ref. 4.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 883–886, May, 1993.     

A study of the tautomerism of the N-butyl-4(2)-methoxycarbonyl-pyrrolid-3-ones and their hydrochlorides

The tautomerism of N-butyl-2-methoxycarbonyl-4-methylpyrrolid-3-one (I), N-butyl-4-methoxycarbonylpyrrolid-3-one (II), N-butyl-4-methoxycarbonyl-2-methylpyrrolid-3-one (III), N-butyl-4-methoxycarbonylpyrrolid-3-one hydrochloride (IV), and N-butyl-4-methoxy-carbonyl-2-methylpyrrolid-3-one hydrochloride (V) has been studied by UV and IR spectroscopy. It has been found that the esters I–V are highly ionized in aqueous and ethanolic solutions at concentrations of 10^–2–10^–3 M. On passing from methyl cyclopentran-1-one-2-carboxylate to the esters II and III the position of the equilibrium in heptane and CCl₄ shifts in the direction of the keto form. On passing from the esters II and III to the esters IV and V, the position of the equilibrium shifts in the direction of the enol. Meyer's relationship is not satisfied for the esters II and III, while it is satisfied for the esters IV and V. Hypotheses have been put forward on the causes of the phenomena mentioned.     

A theoretical method of researching ion-molecule reactions in solution

A method has been devised for researching the mechanisms of ion-molecule reactions in aqueous solutions, which involves deriving an approximate reaction path by means of a model Hamiltonian, in which the medium is described by a set of point Langevin dipoles. At the stationary points on the PES derived in that way, the solvation may be simulated by means of a more accurate scheme for the medium, namely by direct optimization of the potential energy for the solvate shell. The method has been tested on the reaction CO₂+OH^–HCO₃ ^–. The model Hamiltonian has been constructed by MINDO/3. Good agreement with experiment is obtained.Translated from Teoreticheskaya i Éxperimental'naya Khimiya, Vol. 23, No. 3, pp. 281–288, May–June, 1987.     

Recyclization of 2-imino-2h-1-benzopyrans under the influence of nucleophilic reagents. 1. New approach to the synthesis of 3-(1,3,4oxadi-, thiadi-, and triazolyl-2)coumarins

It has been found that under the action of hydrazides of carboxylic acids, 2-iminocoumarin-3-carboxamides are recyclized to N⁽¹⁾-acylamidrazones of coumarin-3-carboxylic acids. The use of N⁽¹⁾-acylamidrazones is proposed as a simple and effective means of synthesizing 3-(1,3,4-oxadi-, thiodi-, and triazolyl-2)coumarins. The possibilities of alternate schemes of synthesis are discussed, and a mechanism is suggested for the recyclization.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 186–192, February, 1996.     

Influence of tartrate ions on the coprecipitation of some trace metal inner complex compounds with bis(8-quinolyl)disulphide

The coprecipitation of Fe(III) quinoline-8-thiolate (QT) with bis (8-quinolyl) disulphide has been investigated with 1 mol × dm^–3 potassium tartrate and 0.001 mol × dm^–3 aqueous tartaric acid solutions in dependence on their pH. In return QTs of Cu(II), Cd(II) and Hg(II) have been coprecipitated from 0.2, 0.1, 0.01 and 0.001 mol × dm^–3 aqueous solutions of tartaric acid after adjusting the pH to 6–7. These tartaric acid concentrations relate to their initial concentrations before the coprecipitation. The presence of tartrate ions influences the recovery of the coprecipitated Fe(III), Cd(II) and Hg(II) QTs. A complete coprecipitation of the Cu(II) inner complex compound can be achieved from the aqueous solutions indicated.     

3-Hydroxy-2-(2"-Thienyl)-4H-Chromon-4-one as a Spectrophotometric Reagent for the Trace Determination of Zirconium in an Aqueous Phase

A rapid, simple, selective, and sensitive method for the trace determination of zirconium has been developed based on the reaction of 3-hydroxy-2-(2"-thienyl)-4H-chromon-4-one in an hydrochloric acid medium to form a yellow–colored complex which is rendered water soluble by the micellar action of Triton X-100 and measured at 415 nm. Most of the metal ions do not interfere with the determination. Beer's law is obeyed in the concentration range 0–2.0 g/mL and the molar absorptivity of the complex is 2.73 × 10⁴L mol^–1cm^–1; Sandell's sensitivity is found to be 0.0034 g cm^–2. The method has been applied for the determination of zirconium in various samples, and satisfactory results have been obtained.     

Influence of metal ions on the activity and stability of the glucose isomerase from Streptomyces atratus

The influence of a number of bivalent metals on the activity ofStreptomyces atratus glucose isomerase has been studied. Mg²⁺ ions are activators and Co²⁺ ions are stabilizers of the glucose isomerase activity. The effective kinetic parameters for the action of the enzyme have been determined.Institute of Microbiology, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 838–842, November–December, 1991.     

Adsorption of traces of hafnium on manganese dioxide from acid solutions

Adsorption of hafnium on manganese dioxide from nitric and perchloric acid solutions has been studied and optimized with respect to shaking time, concentration of acid, oxide and metal. Maximum adsorption has been noticed from 0.1 mol · dm^–3 acid solutions in 20 minutes around 10^–5 mol · dm^–3 hafnium concentration. The adsorption of hafnium follows a Freundlich adsorption isotherm. Oxalate, thiosulfate, Na(I) and Al(III) from nitric acid and K(I) and Zn(II) from perchloric acid increase the adsorption, whereas all other anions and cations tested reduce the adsorption from both media Fe(III) and Sn(IV) significantly. Zn(II) and Co(II) show low adsorption affinity.     

Nonempirical calculations of potential-energy surfaces for nucleophilic addition of H− and F− to an acetylene molecule

The minimal energy paths for the nucleophilic addition of a hydride ion (H^–) and a fluoride ion (F^–) to a molecule of acetylene (A) have been calculated with the use of 3–21++G and 3–21+G double basis sets in the framework of the Hartree-Fock-Roothaan method. The values of the total energies of the reactants, transition states, and products have been refined by means of calculations with more complete basis sets [6–31++G// 3–21++G and 6–31++G*//3–21++G for reaction (1); 6–31+G*//3–21+G and 6–31++G**//3–21+G for reaction (2)] and by taking into account the correlation energy for reaction (1) in the framework of the SCEP/6–31++*//3–21++G method. It has been established that the activation energy of reaction (2) is 15.94 kJ/mole lower than that for reaction (1), that reaction (1) is exothermic, and that the enthalpy change accompanying reaction (2) is close to zero. The character of the distribution of the electron density along the minimal energy paths of both reactions has been analyzed, and the differences appearing as a result of the replacement of the soft nucleophile H^– by the harder nucleophile F^– have been ascertained. The results of the calculations have been compared with the results available in the literature for reaction (1).Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 149–155, March–April, 1989.     

Electrodeposition of Lu on W and Al electrodes: Electrochemical formation of Lu–Al alloys and oxoacidity reactions of Lu(III) in the eutectic LiCl–KCl

The electrodeposition of lutetium on inert electrodes and the formation of lutetium–aluminium alloys were investigated in the eutectic LiCl–KCl in the temperature range 673–823 K. On a tungsten electrode, the electroreduction of Lu(III) proceeds in a single step and electrocrystalization plays an important role. Experimental current–time transients are in good agreement with theoretical models based on either instantaneous or progressive nucleation with three dimensional growth of the nuclei, depending on the working temperature. The diffusion coefficient of Lu(III) was determined by chronopotentiometry by applying the Sand equation. The activation energy for diffusion was found to be 31.5 ± 1.3 kJ mol⁻¹. Al₃Lu and mixtures of Al₃Lu and Al₂Lu, characterized by XRD analysis and SEM, were obtained from the LiCl–KCl melt containing Lu(III) by potentiostatic electrolysis using an Al electrode. The activity of Lu and the standard Gibbs energies of formation for Al₃Lu were estimated from open-circuit chronopotentiometric measurements. The E–pO²⁻(potential–oxoacidity) diagram for Lu–O stable compounds in LiCl–KCl at 723 K has been constructed by combining theoretical and experimental data. In this way, the apparent standard potential for the Lu(III)/Lu system has been determined by potentiometry. Potentiometric titrations of Lu(III) solutions with oxide donors, using a yttria stabilized zirconia membrane electrode “YSZME” as a pO²⁻ indicator electrode, have shown the stability of LuOCl and Lu₂O₃ in the melt and their solubility products have been determined at 723 K.     

A method of calibration of the formic acid monomer concentration in the gas phase

Pyrolysis of t-butyl formate, (CH₃)₃C-O-CHO, has been carried out in a carrier gas stream of Ar or N₂ in a temperature range of 200–400°C. Between 200 and 300°C, the pyrolysis yielded an equimolar mixture of HCOOH and (CH₃)₂C=CH₂. The results have been used as a calibration method for determining the concentration of the gas-phase HCOOH monomer without interference from the formation of the formic acid dimer. Using this technique, the gas-phase infrared absorption cross-section of HCOOH at 1105 cm^–1 (peak to valley) for the resolution of 0.5 cm^–1 has been determined to be 6.76×10^–19 cm² molecule^–1.     

Electronic absorption spectra,ESR spectra,and structure of coordination polyhedrons of titanium(III) in molten and “instantly cooled” systems of sodium phosphates and halides

The structure of Ti(III) coordination polyhedrons in both individual NaPO₃ and 70 mole % NaPO₃-30 mole % Na_nX mixtures (X=PO₃ ^3–, P₂O₇ ^4–, F^–, Cl^–) in the molten and solid states has been investigated on the basis of data from electronic absorption and ESR spectra. The formation of tetragonally distorted Ti(III) coordination polyhedrons with D_4h symmetry coordinated only by (PO₃ ^–)_n chains with the following values of the spectroscopic parameters for the molten (and solid) states has been established in all the phosphate systems investigated: 10Dq=17,300 (18,000) cm^–1 (Ds=50 cm^–1, Dt=5600, g=1.959, g₁=1.930, =93. cm^–1). It has been shown that the greater is the extent of depolymerization of the phosphate chains in the melt, the stronger is the Ti(III) coordination polyhedron formed; the following relative series of the depolymerizing strength of the anions has accordingly been established: PO₄ ^3–2O₇ ^4–––.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 5, pp. 610–614, September–October, 1989.