Reactions with Addition Compounds Containing Activated Formic Acid

Addition compounds of formic acid with tertiary organic bases in ratios higher than that required for salt formation (3:1 and 2:1 adducts) contain formic acid in a highly activated form. In particular, the 3:1 adducts of formic acid with trimethylamine and triethylamine are liquid reducing agents that are convenient to handle and are suitable for use in many selective reductions. These addition compounds have a surprisingly strong reducing action on sulfur dioxide, which is rapidly converted, even at low concentrations, into crystalline rhombic sulfur. Sulfones and polysulfones can be prepared in good yields by three-component reactions from activated formic acid, sulfur dioxide, and polarized vinyl compounds.     

丝网印刷普鲁士蓝修饰电极催化还原测定过氧化氢

制备了普鲁士蓝修饰的丝网印刷过氧化氢传感器,研究了过氧化氢在该修饰电极上的电催化还原特性,考察了有关修饰膜制备和试验条件对传感器性能的影响。结果表明,pH4.0的0.2mol·L-1KH2PO4 K2HPO4缓冲溶液(PBS)中,修饰电极对过氧化氢显示出快速的电化学响应,较高的稳定性、重现性和催化活性,测定的线性范围为1.0×10-5～1.0×10-3mol·L-1,相关系数为0.999,检出限为6.0×10-6mol·L-1(3σ)。电极制作方法简便,可用于实际样品的测定。     

Titanosilicates as Supports for an Enzymatic Alcoholysis Reaction

Novel [Cr^III(amp)(bipy)(Cl)] (1) (H₂amp = N-(hydroxyphenyl)salicyldimine; bipy = 2,2-bipyridyl) and [Cr^III(app)(bipy)(Cl)]⁺ (2) (H₂app = N-(hydroxyphenyl)pyridine-2-carboxaldimine; bipy = 2,2-bipyridyl) complexes have been synthesized and characterized by physico-chemical methods. Complexes 1 and 2 have been employed as catalysts in the oxidation of both saturated and unsaturated hydrocarbons using tert-butylhydroperoxide (t-BuOOH). The significance of the results with respect to oxo-functionalization of C-H bonds both in unsaturated and saturated hydrocarbons is noted.     

Synthesis of a novel 18β-glycyrrhetinic acid derivative

A novel compound, biotinylated 18β-glycyrrhetinic acid (BGA), was synthesized. It is a compound of 18β-glycyrrhetinic acid linked with biotin. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 266–267, May–June, 2006. An erratum to this article is available at .     

无保护流体室温燐光法测定吲哚-3-丁酸的研究

在仅以碘化钾为重原子微扰剂、亚硫酸钠为除氧剂及无任何保护性介质存在的水溶液中 ,吲哚_3_丁酸 (IBA)能发射很强的室温光 (RTP) ;详细研究了分析测定条件及有机溶剂对RTP的影响 ;在最大光波长λex/λem =281/447nm处 ,光强度与IBA浓度在2.0×10 -7～1.0×10 -5mol/L范围内呈良好的线性关系 ,检出限4.3×10-8 mol/L ;方法直接用于强化水样和土壤中IBA的测定 ,回收率96 %～104 % ,相对标准偏差2.37 %～3.97 %。     

A kinetic approach to homogeneous Ziegler type polymerization. Steady state

In this paper we present a kinetic approach to the analysis of steady-state homogeneous Ziegler-Natta polymerization activity data. The influence of the number of monomeric species that are coordinated to the active site on the apparent rate law is discussed and the equations are fitted to the experimental results.     

Effects of <Emphasis Type="Italic">L</Emphasis>-Carnitine on Sucrose-Induced Hyperlipidaemia

Summary. L-Carnitine, L-(−)-β-hydroxy-γ-trimethylaminobutyrate, plays an important role as a factor necessary for the transport of long-chain fatty acids into the mitochondria. In order to investigate the influence of L-carnitine on hyperlipidaemias, the experimental model of the sucrose-induced hypertriglyceridaemia of the rat was used. In these experiments L-carnitine in the dose of 11 mg per day and 100 g body weight (over the period of 1 week) was able to antagonize the sucrose-induced hypertriglyceridaemia and the increase of serum free fatty acid level in female rats of the Wistar strain. Carnitine administration did not change the activities of lipogenic enzymes and fatty acid synthesis in the liver. However, L-carnitine increases the rate of hepatic fatty acid oxidation. Our results indicate a hypotriglyceridemic and free fatty acid lowering effect of L-carnitine, and suggest the use of this compound in the therapy of hyperlipidaemias.     

Characterization of Saccharomyces Sp. through determination of amino acid profiles by capillary gas chromatography

The Saccharomyces strains uvarum, montuliensis, bayanus, capensis and florentinus were grown in liquid media prepared from a 1% aqueous glucose solution to which 0.05% of ammonium sulfate or urea were added as the only nitrogen supply. The amino acids exuded during incubation were isolated by cation exchange and derivatized as the corresponding N,O-heptafluorobutyryl isopropyl esters. Separation was achieved on a highly deactivated glass capillary column coated with OV-101. A characteristic amino acid profile was obtained for each of the species studied, allowing the construction of a chemotaxonomic tree, on the basis of present or absent acids.     

Interaction of (1-phenylethyl)indole-2-carbonitrile with C-nucleophiles

Methods of obtaining ketones and enamino esters have been developed on the basis of reactions of 1-(1-phenylethyl)indole-2-carbonitrile with organomagnesium and organozinc compounds. Removal of a benzyl group from the indole nitrogen atom by the Grignard reagent has been discovered. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1179–1183, August, 2006.     

Investigation of the phosphinyl analog of α-ketoglutaric acid

It was shown by³¹P and¹³C NMR spectroscopy that methyl(3-carboxy-3-oxopropyl)phosphinic acid (4-methylhydroxyphosphinyl-2-oxobutyric acid) (1) and the amide (2) of the latter exist in keto forms in non-aqueous solutions. In aqueous solutions an equilibrium between the keto,gem-diol, and enol forms has been observed. The proportions of the diol and enol forms increase as the acidity of the media increases. Silylation of acid 1 with hexamethyldisilazane gives the tris(trimethylsilyl) derivative of enol form (3) (Z- andE-isomers).Translated fromIzyestiya Akadetnii Nauk. Seriya Khimicheskaya, No. 1, pp. 125–128, January, 1994.