Determination of ametoctradin in plant residues and environmental samples by HPLC with an UV detector

The study deals with the development of a method for the determination of ametoctradin by HPLC with UV detection. Samples were extracted with aqueous acetone and then purified by distribution between immiscible solvents and also on solid-phase extraction cartridges. The procedure was tested in the determination of ametoctradin in water in the range 0.001–0.01 mg/L, in soil, potato vine and potato tubers, salad, onion, cucumber, tomatoes, carrots, grapes, and grape juice in the range from 0.005 to 0.1 mg/kg, depending on the matrix. The average recoveries were 78?92% with RSD < 0.08%. The proposed procedure is applicable to the determination of ametoctradin in environmental samples and plant residues.     

Conjugates of Bispidine and Monoterpenoids as Ligands of Metal Complex Catalysts for the Henry Reaction

Russian Journal of Organic Chemistry - A number of chiral chelating conjugates combining a bispidine central backbone and one or two pinene side fragments were synthesized. It was shown for the...     

Main stages in the development of domestic alkaloid chemistry

The following are considered: 1) the study of alkaloids in Russia before the Great October Socialist Revolution. 2) The development of industry and of scientific investigations in the field of alkaloid chemistry at the end of the XIXth and the beginning of the XXth centuries and the influence of social factors on the development of this part of knowledge. 3) The work of Academician A. P. Orekhov and his school, which opened up a new direction in the development of alkaloid chemistry. 4) The achievements of the modern school of alkaloid investigators in the USSR.M. V. Lomonosov Moscow State University. A. A. Zhdanov Irkutsk State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 757–771, November–December, 1979.     

Polyphosphorus ligands,containing P(III) and P(V) in the molecule,and their complexes with palladium

Conclusions New polyphosphorus compounds are synthesized which contain atoms of P(III) and P(V): tetraphenylethylenediphosphine monoxide, phenylbis(-diphenylphosphorylethyl)phosphine, and phenylbis(-diphenylphosphinoethyl)phosphine oxide. Their acid-base properties and their complex formation with Pd(II) were studied.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 673–678, March, 1980.     

Optimization of silicon dioxide surface functionalization protocol for designing the receptor layer of a biosensor for detecting explosives

The development of the receptor layer of the biosensor for detecting explosive compounds is described. The covalent modification has been chosen for immobilizing E. coli nitroreductase on the gate oxide of the ion-sensitive field effect transistor (ISFET) that is comprised of silicon dioxide. The self-assembled monolayer technique has been used for immobilization. This method assumes the usage of different silanes and spacer molecules for activating the surface of SiO₂. Two different immobilization strategies have been compared, one using asymmetric spacers (3-maleimidobenzoic acid N-hydroxysuccinimide ester (MBS) and 4-(4-maleimidophenyl)butyric acid N-hydroxysuccinimide ester (SMPB)) and another using a symmetric glutaric dialdehyde linker both accompanied by appropriate silanes. For the first method, the dependence of functionalization efficiency on silane concentration has been studied. The sufficient density of enzyme molecules on the surface of SiO₂ has been achieved at a concentration of silane of 0.0015%. The type of asymmetric linker has no influence on immobilization efficiency. The method implying glutaric dialdehyde results in higher activity of the immobilized enzyme. For this method, the immobilization procedure has been optimized. The method has been adapted for immobilization of E. coli nitroreductase inside the channel of a microfluidic system on the surface of ISFET. For this purpose, (3-aminopropyl)triethoxysilane (APTES) has been changed to the corresponding silatrane, and the concentration of the enzyme has been increased to 30 μg/mL. The optimized procedure has been successfully used to develop a biosensor for detecting explosives.     

An efficient procedure for the synthesis of Esomeprazole using a titanium complex with two chiral ligands

A procedure has been proposed for the selective preparation of Esomeprazole via asymmetric oxidation of the corresponding prochiral sulfide in the presence of a catalytic complex derived from titanium(IV) isopropoxide and two different chiral ligands, diethyl d-tartrate and (R)-N,N-dimethyl-1-phenyl-ethanamine.