Investigation of the products of the ozonolysis of larixol

On the ozonization of larixol in methanol followed by treatment with ammonium chloride, the main reaction products were 15,16,20-trisnorlabd-6-ene-8,13-dione and 6-hydroxy-8,13;8,14-diepoxy-15,20-bisnorlabd-14-one. When ozonization was performed in methanol in the presence of dimethyl sulfide or in methylene chloride in the presence of pyridine, 6,14-dihydroxy-8,13;8,14-diepoxy-15,20-bisnorlabdane and 6-hydroxy-14,50,20-trisnorlabd-8,13-dione predominated in the reaction products.Institute of Chemistry of the MSSR Academy of Sciences, Kishinev, and Institute of Organic Chemistry of the Bashkir Branch of the USSR Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 577–584, September–October, 1986.     

Synthesis of a Pair of Derivatives of N-Methylpyrrole Polyamide

A pair of derivatives of tetrameric N-methylpyrrole polyamide were synthesized in order to develop a new method for the study of interaction of the polyamide derivatives with DNA. Indole acetic acid and nicotinic acid were introduced to the polyamide in the synthesized compound, which showed an expected red shift in the UV spectrum. These compounds may function as a potential tool in the detection of the polyamide binding to DNA.     

Investigation of the products of the ozonolysis of larixol

On the ozonization of larixol in methanol followed by treatment with ammonium chloride, the main reaction products were 15,16,20-trisnorlabd-6-ene-8,13-dione and 6-hydroxy-8,13;8,14-diepoxy-15,20-bisnorlabd-14-one. When ozonization was performed in methanol in the presence of dimethyl sulfide or in methylene chloride in the presence of pyridine, 6,14-dihydroxy-8,13;8,14-diepoxy-15,20-bisnorlabdane and 6-hydroxy-14,50,20-trisnorlabd-8,13-dione predominated in the reaction products.     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

缺Zn症患儿微量元素水平的样本特征分析及其临床补Zn治疗的评价

测定了150例缺Zn症患儿及健康儿发样中的Zn、Ca、Mg及Fe四元素水平．采用主成分分析法．将高维空间中的样本点映射到低维空间中来观察，研究其样本特征，评价临床补Zn治疗措施．结果瑶明：缺Zn症患儿体内缺Zn是病理的主要方面，但往往同时伴有其它微量元素水平偏低现象，临床缺Zn症状的表现可能为多种元素综合效应的反映．因此临床治疗不能单纯考虑朴Zn，还应结合患儿体内其他元素水平的具体情况，考虑其他元素的补给．治疗才能奏效显著．     

成都市城市绿地土壤理化性质研究

对成都市绿地土壤的理化性质进行了研究,并与郊区的土壤作了比较.结果显示,该市绿地土壤的pH明显高于市郊,而有机质含量和总硫含量则低于市郊.     

Structure of the products of the photoreaction of osthole

The results are given of a study of the photoreaction of osthole in chloroform and acetophenone. It has been shown that when it is irradiated in the latter solvent the cyclization characteristic for coumarins takes place at the double bonds both in the 3,4- position of the coumarin ring and in the side chain, leading to the formation of cyclobutane structures.Leningrad Sanitary-Hygienic Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 165–168, March–April, 1980.     

Study of the properties of pentasil-containing catalysts in reactions of transformation of hydrocarbons

The kinetics of transformations of propane and propylene on pentasils modified with zinc, Zn/HTsVM, and the H form of zeolite were investigated. Quantitative data were obtained which revealed significant differences for HTsVM and Zn-containing catalysts in the selectivity of transformations of propane with different degrees of its conversion. The promoting effect of Zn in the Zn/HTsVM system not only on the stage of dehydrogenation of propane into propylene, but also on subsequent transformations of propylene into aromatic hydrocarbons, was demonstrated. The absence of internal diffusion inhibition of the reaction in the conditions studied was demonstrated experimentally. It was shown that aromatization of propane takes place in the kinetic region.For previous communication, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 727–733, April, 1990.     

Effect of Pore Structure of Al-Co-Mo Catalyst on the Rate of Various Pathways of Hydrofining of Oil Residues

Evolution in the activity and texture of the Al-Co-Mo catalyst in hydrofining of black oil is studied. The catalyst efficiency in desulfurization, deasphalting, and demineralization of black oil is estimated as dependent on the catalyst pore structure and process conditions.     

Composition of lipids of the grain of opaque-2 maize

It has been established that the change in the composition of the total lipids and the fall in the fatty acid content depend on the initial maize genotype. A decrease in the amount of unsaponifiable substances in the grain of mutants is accompanied by qualitative changes in the composition regardless of the nature of the genotype.Scientific-Research Institute of Biology Dnepropetrovsk State university. Translated from Khimiya Prirodnykh Soedinenii. No. 3. pp. 360–363. May–June, 1988.     

Thermodynamic parameters of solvation of nonelectrolytes in aqueous solutions of amides of carboxylic acids

Interaction and reorganization contributions to solvation enthalpies of nonelectrolytes in aqueous solutions of amides of carboxylic acids with different degree of N-substitution and N-methylpyrrolidone are calculated. The data are discussed using structurally thermodynamic characteristics of water-amide systems obtained by us previously. It is found that the type of concentration dependence of the solvation enthalpy of nonelectrolytes in all solutions investigated is determined by the type of reorganization component. It is shown that the highest solvation exothermicity of nonelectrolytes in water is due to the lowest value of the reorganization contribution in spite of that nonelectrolytes interact weaker with water than with non aqueous components.     

Rapid thermal analysis of processes of thermal decomposition of mineral salts

Kinetic curves of thermal decomposition and synthesis of mineral salts are obtained in the conditions of rapid heating approaching the heating conditions in a low-temperature plasma flow. The kinetic characteristics are used in calculations of transformations in the path of a chemical plasma reactor.

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Zusammenfassung Für thermische Zersetzung und Synthese von Mineralsalzen wurden die kinetischen Kurven unter den Bedingungen schnellen Aufheizens in Annäherung der Aufheizbedingungen in einem Niedertemperatur-Plasmastrom ermittelt. Die kinetischen Eigenschaften wurden zur Berechnung der Umwandlungen bei einem chemischen Plasmareaktor verwendet.

     

Improvement of the efficiency of electrochemical refining of cobalt

To improve the purity of cobalt produced by electrochemical refining, the optimal electrolyte composition and electrolysis mode were determined and a method for diminishing the electrochemical activity of impurity metals in anodic dissolution of the raw metal and a system for deep purification of the electrolyte solution to remove impurities were developed. Cathode deposits with a conditional cobalt content exceeding 99.999 wt %, found in an analysis for the 11 main impurities, were obtained by using the above results in refining of K1A cobalt (≥99.30 wt % Co) in an electrolyzer of distinctive design.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Determination of the extent of acid hydrolysis of N-methylpyrrolidone

The extent of the hydrolysis of N-methylpyrrolidone in dilute hydrochloric acid can readily be determined by titrating an aliquot of the reaction mixture in absolute ethanol with tetrabutylammonium hydroxide. A separate equivalence point is observed in the titration curve for each of the three types of ionisable hydrogens involved.     

Study of Self-Ignition of PVC

The self-ignition of rigid PVC has been studied under static and dynamic conditions. Only a high-temperature boundary has been found, and the self-ignition temperature in air at atmospheric pressure lies between 555 and 560°C. The effect of preliminary HC1 evolution has been investigated, and it is shown that the more the HC1 evolution, the higher the self-ignition limit. It has been impossible to make polyacetylene ignite spontaneously in the presence of HC1 in oxygen up to 900° C. This is attributed to a special role of HC1 in combustion of PVC. The rate of HC1 release was measured by a potentiometric method, and the overall activation energy of the process was found to be 9.4 kcal/mole. This low value seems to be due to the presence of oxygen. Chromatographic analysis showed CH4 and CO to be the major gaseous products of oxidation of PVC in this parametric zone.     

Preparation of composite membranes by means of plasma polymerization of tiophene

The structure and the charge transport properties of poly(ethylene terephthalate) track membranes modified in a thiophene plasma were studied. It was found that polymer deposition on the surface of a track membrane via the plasma polymerization of thiophene results in composite membranes that, in the case of the formation of a semipermeable layer, exhibit conductivity asymmetry—rectifying effect—in electrolyte solutions. It was shown that chemical doping with iodine or photo-oxidation of the polymer layer produced in plasma leads to alteration in the electrochemical properties of plasma-modified membranes.     

生物催化产业化进展

生物催化吸引人的特征包括高效性、多样性、底物专一性、区域选择性、化学 选择性、对映选择性以及温和的反应条件．总结了一些化学公司当前在生物催化产 业化方面所取得的成就．预计在今后的十年间，将会有更多优于传统化学路线的生 物催化方法被广泛地应用于各种精细化学品的工业生产中.     

Investigation of the lability of the conformations of some alkaloids of the quinolizidine series

Summary The IR and NMR spectra of lupinine, epilupinine, and a series of other alkaloids of the quinolizidine series have been studied.It has been shown that the inhibition of the inversion processes in the molecules of the alkaloids in the solid phase is revealed in a change in the nature of the absorption in the 500–1200 cm^2–1 region.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 49–54, January, 1971.     

Effect of composition of coordination sphere on value of constant of additional hyperfine structure of EPR spectra

Conclusions Replacing the oxygen atoms by sulfur atoms in the coordination sphere of nitrogen-containing copper complexes leads to a substantial increase in the constant of the additional hyperfine structure from the nitrogen atoms, and consequently also to an increase in the degree of covalency of the Cu-N bonds.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 704–706, March, 1974.The authors thank V. I. Nefedov for taking the x-ray electronic spectra of compounds (I) and (II).