Synthesis of isocryptolepine,an alkaloid fromCryptolepis sanguinolenta

Isocryptolepine, an alkaloid recently isolated from the roots ofCryptolepis sanguinotenta, was synthesized by selective methylation at the N(5) atom of 11H-indolo(3,2-c]quinoline with excess Mel in toluene.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp.2795–2796, November,1996     

Synthesis of allenic thioethers of the pyridine series

-Picolyllithium and 2,6-lutidyllithium add to alkylthiovinylacetylenes to form adducts which, after demetallation with water, form allenic thioethers of the pyridine series.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3,pp. 354–355, March, 1971.     

Synthesis of polybrominated diphenyl ethers of marine origin

Polybrominated diphenyl ethers — antimicrobial metabolites of the marine spongeDysidea fragilis — have been obtained by the reaction of 2,3,5-tribromonitrobenzene with 3,5-dibromo-2-methoxyphenol and the reaction of brominated diphenyliodonium salts with brominated phenols.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 352–354, May–June, 1993.     

Thermal decomposition of oxalates and nitrates of transplutonium elements by differential thermal analysis

Thermal decomposition of oxalate and nitrate hydrates of transplutonium elements has been studied by differential thermal and X-ray analysis, under heating in helium and oxygen. The formation heats of anhydrous crystalline Am(III) and Cm(III) nitrates were estimated from DTA data. Data of the self-decomposition of²⁴⁴Cm(III) salts under the influence of inherent -radiation were obtained.     

Uniform integrability for integrals with respect to Lo-valued measures

Integrals of real functions with respect to L_o-valued measures are considered. It is proved that if the functions f_n converge in measure to f, then f_nd fd if and only if some condition holds for f_n, similar to the condition of uniform integrability for integrals with respect to scalar measures.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 43, No. 9, pp. 1264–1267, September, 1991.     

Atmospheric pressure laser desorption/ionization on porous silicon

A recently developed commercial atmospheric pressure matrix-assisted laser desorption/ionization (AP-MALDI) source (MassTech, Inc.) was modified to adopt commercially available DIOS plates (Mass Consortium Corp.) for the studies of laser desorption from the surface of porous silicon under atmospheric pressure conditions. The feasibility of atmospheric pressure laser desorption/ionization from the surface of porous silicon (AP-DIOS) was demonstrated. The advantages of this new AP-DIOS technique include reasonably good sensitivity (subpicomole range for standard peptide mixtures), simplicity of sample preparation, uniformity of target spots and the absence of matrix peaks in the spectra. The AP-DIOS source was interfaced with a commercial ion trap (LCQ Classic, Thermo Finnigan) which additionally provides a unique MS(n) capability. The AP-DIOS spectrum of 250 fmol of unseparated tryptic digest of bovine serum albumin (BSA) was compared with that of AP-MALDI for the same compound. AP-DIOS offers significantly better coverage for the digest components in the mass range 200-1000 Da. The combined data of both techniques enabled us to nearly double the number of matched peaks in BSA digest analysis compared with AP-DIOS or AP-MALDI analysis separately.     

Molecular design of N,N-disubstituted 2-aminothiazolines as selective carboxylesterase inhibitors

Selective carboxylesterase inhibitors are employed as modulators of hydrolytic metabolism of ester or amide-containing drugs. Using the Molecular Field Topology Analysis (MFTA), the models for the relationships between the structures and inhibitory activities of 5-halomethyl-2-aminothiazolines against acetylcholinesterase, butyrylcholinesterase, and carboxylesterase were built, the molecular design was performed, and a focused library of potentially active and selective carboxylesterase inhibitors was proposed.     

Magnetoelectric effect in layered disk-shaped magnetostrictive–piezoelectric structures: Theory and experiment

Theoretical and experimental studies of the magnetoelectric effect in a disk-shaped magnetostrictive–piezoelectric structure in the electromechanical resonance region are presented. An expression for the magnetoelectric voltage coefficient is derived based on the simultaneous solution of elastodynamic and electrostatic equations separately for magnetostrictive and piezoelectric layers. The conditions at the interface were taken into account based on the premise that the interaction between layers is implemented by shear. It is shown that the inhomogeneity of the voltage and strain distribution over the sample thickness, caused by the interface, leads to a significant contribution to the effect in the case of thick layers. The theoretical and experimental dependences of the frequency characteristic of the effect are presented for the permendur–lead zirconate-titanate–permendur structure. The theoretical calculations are in good agreement with experimental data.