Electrodiffusion of ions inside living cells

Electrodiffusion of ions, both inside and outside biologicalcells, are of utmost importance to proper cellular functions.Experiments indicate that both ion concentrations and electropotentialcan jump discontinuously across the cell membranes. We studya system of nonlinear partial differential equations modellingsuch phenomena. Jump conditions for species concentrations andelectropotential across cell membranes are imposed. Under zero-fluxboundary conditions for one-dimensional domains, the solutionsare proved to exist for all times. With further assumptions,these transient solutions will converge to the unique steady-statesolution. Numerical experiments in one- and two-dimensionaldomains are also performed in order to study some unresolvedtheoretical issues.     

Nucleophilic substitution in hydroxyisoxazolidines

Nucleophilic substitution of the hydroxy-group in 3- (or 5-)hydroxyisoxazolidines affords the aryl(alkyl)amino-, alkoxy-, and hydrazino-compounds. 5-Dimethylhydrazinooxazolidines exist preferentially in the linear form.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1661–1665, December, 1988.     

Synthesis of 5-hydroxy- and 5-acylhydrazinopyrazolidines by the reaction of β-substituted hydrazides with α,β-unsaturated aldehydes and their biological activity

The reaction of -substituted hydrazides with alkenals (acrolein, methacrolein, crotonaldehyde, and cinnamaldehyde) serves as a method for the synthesis of the corresponding 1-acyl-5-hydroxypyrazolidines and, in a number of cases, 1-acyl-5-acylhydrazinopyrazolidines. Some of the 1-acyl-5-hydroxypyrazolidines obtained have antiphlogistic activity.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 659–666, May, 1984.     

Synthesis of isoxazolidine derivatives from N-substituted hydroxylamines and α,Β-unsaturated ketones

The reaction of methyl vinyl ketone with N-Phenyl-hydroxylamine leads to a tautomeric mixture of 5-hydroxy-2-phenyl-5-methylisoxazolidine and its linear form, while the reaction with benzohydroxamic acid leads to linear products of addition to the oxygen or nitrogen atoms, depending on the reaction conditions. The first representatives of 5-hydroxyisoxazolidines with the residue of an aliphatic carboxylic acid attached to the nitrogen atom were obtained by acylation of 5-hydroxy-3,3,5-trimethylisoxazolidine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 823–826, June, 1989.     

1-Acyl-5-hydrazinopyrazolidines and their ring-chain tautomerism

1-Acetyl-5-hydroxyl-2-isopropyl(phenyl)pyrazolidines, as well as 1-hydroxyperhydropyrazolo[1,2-a]-4H-pyridazine-5,8-dione, react readily with alkyl-, aryl-, and acylhydrazines and hydroxylamine to give the corresponding products of substitution of the OH group, which, depending on the nature of the hydrazine, exist in the linear -hydrazidohydrazone (oxime) form or in the form of a cyclic tautomer, viz., the corresponding 1-acetyl-5-hydrazinopyrazolidine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1238–1241, September, 1985.     

Chemistry of indole

Under the influence of halide compounds of phosphorus, acetic acid -phenylhydrazides that have an alkyl group attached to at least one of the nitrogen atoms form 2-aminoindoles that do not have substituents in the 3 position. Similarly, 1-phenyl-2-acetylpyrazolidines are converted to 1,2,3,4-tetrahydropyrimido[1,2-a]indoles.See [1] for communication XXXV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 647–652, May, 1973.     

Reactivity of metal-containing monomers 66. Hydrogenation of nitrotoluene derivatives in the presence of polymer-immobilized Pd nanoparticles

A new approach to the synthesis of immobilized catalysts of the mixed type was developed: frontal polymerization of metal-containing monomers in the presence of a highly dispersed inorganic support. The synthesis of the acrylamide complex of Pd^II nitrate on the SiO₂ surface followed by polymerization and reduction results in the formation of a polymer-inorganic composite with inclusions of Pd nanoparticles stabilized by the polymer matrix on the support surface. The study of the catalytic properties in the hydrogenation of nitrotoluene derivatives showed that the polymer-immobilized Pd nanoparticles on the inorganic support are efficient catalysts for the reduction of the nitrocompounds.