• Toxicological Research
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• 제2권1호
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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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• 제13권4호
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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.

• 공업화학
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• 제3권4호
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• pp.579-587
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• 1992

올레핀의 오존화 반응에서 보여지는 통상의 반응경로가 pyridine의 도움으로 modification될 수 있는지 여부가 검토되었다. 먼저, trans-3-hexene의 오존 산화 반응이 aprotic non-participating solvent인 n-pentane과 dichloromethane을 사용하여 시험되었다. 덧붙여, 올레핀의 오존 산화 반응에서 pyridine의 역할과 반응기구를 검토하기 위하여, monomeric과 Polymeric ozonides의 염기성 촉매 분해반응이 시험되었다. 본 연구에서 반응 과정의 고찰뿐만 아니라 생성물의 정량, 정성 분석을 위하여 현대적인 분석 기기들이 사용되었다. 본 연구의 결과로서, Pyridine 무존재하 aprotic solvent에서 올레핀과 오존의 반응으로 주로 과산화물인 monomeric이나 polymeric ozonides가 생성되었으며, pyridine 존재하에서는 과산화물의 생성없이 propionaldehyde와 Criegee zwitterion의 자리옮김 생성물인 propionic acid가 주생성물이었다. 또한, tans-3-hexene의 오존 산화 반응에서 Pyridine의 촉매작용에 의하여 trans-3-hexene의 Criegee zwitterion의 propionic acid로 이성화되는 것으로 사료된다.

• Bulletin of the Korean Chemical Society
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• 제23권12호
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• pp.1845-1847
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• 2002

• 공업화학
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• 제5권4호
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• pp.624-629
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• 1994

Chitosan-g-Poly(4-vinyl pyridine)공중합체막을 제조하였으며 Chitosan-g-Poly(4-vinyl pyridine)공중합체막과 아크릴아마이드를 사용하여 glucose oxidase를 포함하는 chitosan/acrylamide 복합막을 제조하였다. Chitosan-g-poly(4-vinyl pyridine)공중합체막의 함수율과 인슐린의 투과량은 용액의 pH가 감소함에 따라 증가하였고, 복합막의 인슐린 투과량은 글루코오스의 농도가 증가할수록 증가하였다.

• 한국대기환경학회지
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• 제3권1호
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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.

• 대한화학회지
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• 제26권5호
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• pp.304-309
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• 1982

Chlorophyll-a(chl-a)와 chlorophyll-b(chl-b)를 pyridine을 포함한 실리콘의 dimer, hexamer에 결합시킨 물질은 중합체의 pyridine 농도와 chl-a의 농도의 비가 1:1일 때 가장 큰 에너지 전이를 나타냈으며 chl-b와 실리콘 중합체는 가장 큰 들뜬 에너지를 나타냈다.

• 한국대기환경학회지
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• 제4권1호
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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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• 제17권7호
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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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• 제19권12호
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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.