• Toxicological Research
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• v.2 no.1
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• pp.31-36
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• 1986

The present work was undertaken to investigate the effect of glycyrrhetinic acid on pyridine toxicity. When glycyrrhetinic acid was pretreated, pyridine-induced CNS depression and mortality were decreased. A striking enhancement of serum transaminase activities after pyridine administration was markedly decreased by glycyrrhetinic acid pretreatment. It was also observed that the hepatic microsomal aniline hydroxylase activity, which is concerned with pyridine metabolism, was significantly increased in glycyrrhetinic acid pretreated mice.

• Archives of Pharmacal Research
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• v.13 no.4
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• pp.342-346
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• 1990

Several new pyridine, pyridinethione, pyrazole [3, 4-b]-pyridine, pyrido [1, 2-a]-1, 3-thiazine and pyrido[1, 2-a] pyridine thione derivatives have be synthesised via the reactions of 2-methyl-3-ethoxycarbonyl-4-phenyl-5-cyano-1, 4, 5, 6-tetrahydro-pyridine-6-one 2 with different rfeagents. The structures of the newly synthesised derivatives were established on the basis of elemental analyses and spectral data studies.

• Applied Chemistry for Engineering
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• v.3 no.4
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• pp.579-587
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• 1992

It was explored, whether the usual course of the ozonolysis of olefins can be modified with the help of pyridine. In the First step, the ozone oxidation of trans-3-hexene was performed with and without pyridine in the inert solvents n-pentane and dichloromethane. In addition, base catalyzed decompositions of monomeric and polymeric ozonides were also examined to identify the reaction mechanism. The reaction products were identified by modern analytical tools. The results of this work showed that reactions of ozone with olefins in the absence of pyridine in aprotic solvents gave, one hand, dominantly peroxidic products, namely monomeric and polymeric ozonides. The other hand, they in the presence of pyridine gave only the non-peroxidic products, namely propionaldehyde and rearranged propionic acid without peroxidic products. It seems, also, that the pyridine-catalyzed isomerization of the Criegee zwitterion of trans-3-hexene to give propionic acid takes place in the ozone oxidation of trans-3-hexene.

• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1845-1847
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• 2002

• Applied Chemistry for Engineering
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• v.5 no.4
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• pp.624-629
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• 1994

Chitosan-g-poly(4-vinyl pyridine)membranes were prepared by crosslinking reaction using glutaraldehyde and glucose oxidase immobilized chitosan/acrylamide composite membranes were fabricated by chitosan-g-poly(4-vinyl-pyridine) copolymer and acrylamine. Water content and permeability of insulin through chitosan-g-poly(4-vinyl pyridine )membranes increased with decreasing the pH of the medium. Permeability of insulin through chitosan/acrylamide composite membranes increased with increasing the concentration of glucose.

• Journal of Korean Society for Atmospheric Environment
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• v.3 no.1
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• pp.1-12
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• 1987

A series of supported sulfided Ni-W/$\gamma-Al_2O_3$ and Co-W/$\gamma-Al_2O_3$ catalysts with different nickel and cobalt contents were studied in the hydrodenitrogenation of pyridine dissolved in n-heptane. The ranges of experimental conditions were at the temperatures between 453 and 753 K, and the pressures between 30 and 50 Bar. The catalytic activities with different nickel and cobalt contents were shown to be maximum at Ni/Ni+W = 0.2 - 0.3, Co/Co+W = 0.3 - 0.4. Pyridine conversion increased with pressure and temperature and the step of piperidine formation was found to be irreversible. The reaction orders in Ni-W/$\gamma-Al_2O_3$ and Co-W/$\gamma-Al_2O_3$ catalysts were the first with respect to pyridine and reaction rate constants decreased with increase of initial pyridine concentration and their activation energies were 12.98 and 9.23 kcal/mol, respectively.

• Journal of the Korean Chemical Society
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• v.26 no.5
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• pp.304-309
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• 1982

The fluorescence yields of chl-a and-b complexes bound to silicon dimer, tetramer and hexamer containing pyridine group in diethyl ether solvent, were shown the transition of excited energy through silicon polymer chain, and the maximum energy quenching were appeared at 1 : 1 ratio of chl-a and pyridine group in silicon polymer but the chl-b complexes were shown the maximum energy of fluorescene emission at the same ratio.

• Journal of Korean Society for Atmospheric Environment
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• v.4 no.1
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• pp.13-22
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• 1988

Interactions between hydrodesulfurization of thiophene and hydrodenitrogenation of pyridine and the kinetic analysis were studied over $Ni-W/\gamma-Al_2O_3$ catalysts and this study was made at temperatures ranging from 473-673 K and at total pressures ranging from 10-25 $\times 10^5$ Pa. Hydrodesulfurization of thiophene was inhibited by presence of pyridine at all temperatures studied, and the rate of pyridine hydrodenitrogenation was slower than that of thiophene hydrodesulfurization in the operating conditions. Pyridine hydrodenitrogenation was also inhibited by the presence of thiophene at low temperatures but was enhanced by the thiophene at temperatures higher than 613K. Thiophene reaction rate was determined by multiple linear regression analysis using Langmuir-Hinshelwood-Hougen-Watson model and the result was given to be $r = kP_T^p_H/(1+K_Tp_T+K_Pp_P)^2$. At each temperature, reaction rate constants and absorption equilibrium equilibrium constants were determined and the activation energy was 12.98 kcal/gmol from Arrhenius plot.

• Macromolecular Research
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• v.17 no.7
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• pp.469-475
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• 2009

We investigated the feasibility of dispersion polymerization without any stabilizer, which has been considered essential for ensuring colloidal stability. By employing small amounts of a lyophilic comonomer, 4-vinyl pyridine, styrene was successfully polymerized by dispersion polymerization in aqueous alcohol without stabilizer to afford stable poly(styrene-co-4-vinyl pyridine) copolymer microspheres. The stable microspheres were produced in the 4-vinyl pyridine range of 2-15 wt% to styrene. Without 4-vinyl pyridine, severely coagulated particles were obtained, implying that the poly(4-vinyl pyridine) moiety endowed colloidal stability. The polymerization kinetics, behavior, and properties of the ultimate particles showed general features of dispersion polymerization. The study results suggest that stabilizer- tree dispersion polymerization is possible, thereby facilitating the synthesis of impurity(stabilizer)-tree polymer particles.

• Bulletin of the Korean Chemical Society
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• v.19 no.12
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• pp.1347-1350
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• 1998

The equivalent conductances for tetraethylammonium perchlorate (TEAP), tetrabutylammonium perchlorate (TBAP), tetrahexylammonium perchlorate (THAP), and tetradodecylammonium perchlorate (TDDAP) were measured in pyridine (Py) at 25 ℃. The measured data have been analyzed by Onsager conductance theory. From Kohirausch's law of independent migration of ion, the limiting ionic conductances of tetraalkylammonium ions were determined using the limiting ionic conductance of perchlorate cited from reference. Using those and viscosity of pyridine, the Stokes and hydrodynamic radii of tetraethylammonium, tetrabutylammonium, tetrahexylammonium, and tetradodechylammonium ions were calculated. And, the salvation numbers of corresponding ions were also calculated using the hydrodynamic and crystallographic radii and the volume of one pyridine molecule. From those results, the model of salvation for those ions was extracted by comparison with the model for ion salvation. And the electrostatic Gibbs free energy (ΔGel) fitted for our salvation model was calculated. Those of corresponding ions in pyridine at 25 ℃ also increased with increasing radii of tetraalkylammonium ions. This trend of ΔGel was explained by the different ion-solvent interaction between tetraalkylammonium ion and pyridine.