Insect pheromones and their analogs LIX. A new method for the synthesis of components of the sex pheromones of insects of the genusMalacosoma

A new method has been developed for the synthesis of the main components of the sex pheromones of insects of theMalacasoma genus that is based on the selective transformation of the product of the partial ozonolysis of cyclohexa-1,4-diene — methyl 6-oxohex-4E-enoate.Institute of Organic Chemistry, Urals Scientific Center of the Russian Academy of Sciences, Ufa, fax (3472) 35 60 66. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 398–401, May–June, 1999.     

α,ω-dicarbonyl 1,5-unsaturated isoprenoids with (Z)-and (E)-configured Δ-bonds in the synthesis of low-molecular-weight bioregulators

Syntheses carried out with participation of the author of terpenoids, polyprenols, prenylcarboxylic acids, insect pheromones, and juvenoids based on α,ω-dicarbonyl 1,5-unsaturated isoprenoid compounds with (Z)- and (E)-configurations, obtained by controlled ozonolysis of isoprene cyclic oligomers and polyisoprene rubbers, are considered. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2040–2051, November, 1999.     

Enantioselective transesterification of (±)-6-benzyloxy-2,5,7,8-tetramethyl-3,4-dihydro-2<Emphasis Type="Italic">H</Emphasis>-1-benzopyran-2-ylmethanol catalyzed by the <Emphasis Type="Italic">Amano PS</Emphasis> lipase in the ionic liquid [bmim]PF<Subscript>6</Subscript>

(S)-(-)-6-Benzyloxy-2,5,7,8-tetramethyl-3,4-dihydro-2H-1-benzopyran-2-ylmethanol, a synthon for the design of natural α-tocopherol, was obtained by kinetically selective acetylation of the corresponding racemic alcohol in the presence of the Amano PS lipase from Burkholderia cepacia in the ionic liquid 1-butyl-3-methylimidazolinium hexafluorophosphate ([bmim]PF₆).     

Antioxidant properties of conjugates of 20-hydroxyecdysone derivatives with a polysubstituted chromanylaldehyde

The antioxidant properties of 20-hydroxyecdysone and its conjugates with (6-hydroxy-2,5,7,8-tetramethylchroman-2-yl)acetaldehyde are reported for initiated 1,4-dioxane oxidation as a model reaction. The antioxidant activity of these compounds is characterized in terms of the effective rate constant of inhibition, fk _In.     

Effect of a peptide modeling the nicotinic receptor binding site on the spectral and luminescent properties of dye complexes with cucurbit[8]uril

The paper presents the results of analysis of the effect of a high-affinity peptide (HAP) homologous to a fragment of the nicotinic acetylcholine receptor (nAChR) on the absorption and fluorescence spectra of thiazole orange and thioflavin T complexes with cucurbit[8]uril in aqueous solution. In the presence of HAP, a change in the absorption spectra of the dye complexes and a drop in the fluorescence intensity occur; for thiazole orange, the fluorescence intensity is restored to the initial level in the presence of α-bungarotoxin capable of high-affinity binding to nAChR. The proposed method make it possible to detect the presence of α-bungarotoxin.     

Association constants and distribution functions for ion pairs in binary solvent mixtures: application to a cyanine dye system

The computations of the association constants K(ass) were performed at the microscopic level for the ion pair Cy(+)I(-) composed of the complex cyanine dye cation Cy(+) coupled to the negative iodine counterion. The wide array of K(ass) values is arranged by a variation of the composition of the binary solvent mixtures toluene/dimethylsulfoxide with the accompanying change of the solvent polarity. The potentials of mean force (PMFs) are calculated for a set of interionic separations R in the Cy(+)I(-) by a methodology which combines the quantum-chemical techniques for the treatment of the electronic structure of the Cy(+)I(-) system with the recent dielectric continuum approach which accounts for the solvation effects. For a given solute/solvent system the probability function P(R), which describes the distribution of interionic separations, is constructed in terms of the PMFs and implemented for the evaluation of the K(ass).     

New Derivatives of 20-Hydroxyecdyzone. Viticosterone E Synthesis

New 20,22-mono- and 2,3:20,22-diacetals of 20-hydroxyecdyzone were synthesized, and some thereof were applied to the synthesis of 25-O-acetyl-20-hydroxyecdyzone (viticosterone E).     

Molecular simulation of solvent-induced stokes shift in absorption/emission spectra of organic chromophores

The values of steady-state solvatochromic Stokes shifts (SS) in absorption/emission electronic spectra of organic chromophores are studied theoretically in the framework of the Hush-Marcus model. Charge distributions for chromophore solutes in their S0 and S1 states are found by means of conventional quantum-chemical methods combined with the continuum PCM approach for treating solvation effects. The solvent reorganization energies, which are expected to correlate with the solvent-induced part of 1/2 SS, are found in a molecular dynamics (MD) simulation which invokes a novel method for separation of the inertial piece of the electrostatic response (Vener, et al. J. Phys. Chem. B 2006, 110, 14950). Computations, performed in two solvents (acetonitrile and benzene), consider three organic dyes: coumarin 153 as a benchmark system and two other chromophores, for which experimental spectra are also reported. The results are found to be in reasonable agreement with the experiment. A consistent treatment of nonlinear effect in the solvent response, promoted by the polarizability of solutes and contributing to the solvent reorganization energies (Ingrosso, et al. J. Phys. Chem. B 2005, 109, 3553), improves the results of computations.     

Combination of ionic liquid [bmim]PF<Subscript>6</Subscript> with boron trifluoride etherate as an efficient catalytic system for the glycosylation of α-tocopherol and naphthotocopherol

The use of a combination of ionic liquid [bmim]PF₆ with boron trifluoride etherate as the catalyst in the glycosylation of α-tocopherol and chromanol of vitamin K₁ (naphthotocopherol) allowed us to obtain β-glycosides in high yield when β-anomer of peracetylated D-glucose was used. In addition, usually inactive α-anomers of peracetylated D-glucopyranose and D-galactopyranose were involved in this reaction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2401–2404, December, 2007.