Synthesis and human leukocyte elastase inhibitory activity of novel 2-spiro(2′,2′-diphenylcyclopropane) cephalosporin sulfones

A new series of 2-spiro(2,2-diphenylcyclopropane) cephalosporin sulfones was synthesizes as potent human leukocyte elastase inhibitors.SynPhar Laboratories Inc., #2 Taiho Alberta Centre, 4290-91A Street, Edmonton, Canada T6R 5V2. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1517–1523, November, 1998.     

Application of umbelliferone molecularly imprinted polymer in analysis of plant samples

The molecularly imprinted polymers (MIPs) were synthesised and the influence of the type of porogen, the nature of sample solvent, and the binding capacity of material were tested by high-performance liquid chromatography (HPLC). Umbelliferone was used as the template for imprint formation. Methacrylic acid was used as the monomer and acetonitrile, ethanol, and chloroform as porogen. Non-imprinted polymers (NIPs) were prepared by the same procedure. The highest value of the specific binding capacity (269 μg of umbelliferone per 100 mg of polymer) was obtained for polymers prepared in chloroform as porogen and methanol/water (φ _r = 1: 1) as the sample solvent. The group-selective MIP was used as sorbent for the SPE pre-treatment of umbelliferone from plant extracts prior to HPLC analysis. Analysis of the spiked samples showed good recoveries (> 77 %). The limit of detection, limit of determination, and repeatability of the method were also calculated.     

Synthesis and spectral properties of mixed-ligand platinum(II) complexes with (-)-<Emphasis Type="Italic">S</Emphasis>-NOBIN and sulfoxides

Synthesis was carried out of the new mixed-ligand square-planar platinum(II)complexes {Pt(R2SO)[(-)-S-NOBIN]Cl₂}, where (-)-S-NOBIN was S-2-amino-2′-hydroxy-1,1′-binaphthyl (R = Me, Et). The complexes are of interest as catalysts for asymmetrical synthesis. The detailed analysis of NMR, UV, and CD spectra of these compounds was performed. These complexes were established to be a mixture of the corresponding cis- and trans-isomers.     

Toward a theory of diffraction by the boundary of a highly reflective medium with periodically modulated characteristics

The problem of diffraction by simultaneously existing surface-profile and impedance gratings in the presence of resonance with a surface electromagnetic wave is examined. The problem is solved in an impedance approximation (Leontovich boundary condition) using Rayleigh's hypothesis. The solution method is based on the distinguishing of resonance fields, for which a finite system of equations is constructed. A proposed regular procedure for exclusion of nonresonance fields makes it possible to obtain a solution with any accuracy for any polarization of the incident radiation and orientation of the gratings. Specific results are given in a principal approximation for the case of several resonances in the first-order spectra.Scientific-Industrial Organization Metrology. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 35, Nos. 3, 4, pp. 234–245, March–April, 1992.     

Reactivity of Geometric Isomers of (–)-Dichloropyridine(methyl-para-tolylsulfoxide)platinum(II) by Optical Rotatory Dispersion

The reactions of the optically active geometric isomers of the platinum(II) complex (–)-[Pt(Me-p-TolSO)(Py)Cl₂] with several nucleophilic reagents (Py, Ph₃PS, Ph₃P, Ph₃As, and Me₂SO) were studied by optical rotatory dispersion, IR spectroscopy, and ¹H and ³¹P NMR spectroscopy. A mechanism for the reaction is proposed.     

Numerical and analytical studies of a nonlinear parabolic equation with boundary conditions of a special form

The work deals with a one-dimensional nonlinear parabolic equation describing the processes of diffusion, filtration and heat conduction. Problems for three kinds of boundary conditions are studied. The analytical study is conducted with the use of solutions in the form of power series; corresponding theorems similar to the Cauchy–Kovalevskaya theorem are proved. Solution algorithms based on the boundary element method are constructed. Some examples are discussed.     

Geometric Photoisomerization of Chiral Platinum(II) Sulfoxide Compounds

Photochemical behavior of platinum(II) sulfoxide-containing complexes in methyl chloride was studied by polarimetry and ¹H NMR spectroscopy.