• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.112-112
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• 1995

간장 손상시에는 여러 혈청의 효소 활성과 함께 혈청 $\beta$-glucuronidase의 활성도 증가한다는 것이 보고되었으나 심한 간부전이나 간암의 경우 이들의 활성은 오히려 정상치보다 감소하는 것으로 나타났다. Silymarin은 간장 보호효과로 이미 임상에 널리 사용되고 있는 약물로서 김 등에 의해 silymarin이 장내세균의 $\beta$-glucuronidase와 간장의 $\beta$-glucuronidase의 활성을 억제한다는 것이 보고되었다. 이에 연자 둥은 $\beta$-glucuronidase의 저해 효과가 관찰된 영지버섯온 유기용매로 분획하여 간장 보호효과를 검색하였다. 영지버섯의 70% MeOH 추출물(GT)과 그 ether 분획(GE)에 대해 생쥐 1군을 6마리로 하여 20% $CCl_4$0.1$m\ell$/10g(olive oil로 희석)을 경구투여 하였다. 검액 GE는 50mg/kg과 250mg/kg, GT는 100mg/kg과 500mg/kg을 각각 사염화탄소 투여 30분 전에 경구투여 하였으며 사염화탄소를 투여하고 24시간 후에 심장 채혈하고 혈청을 분리하여 혈청성분 및 혈청효소의 활성을 측정하였다. 대조군에는 생리식염수를 투여하였고 양성 비교약물로는 silymarln 100mg/kg을 경구투여 하여 비교 관찰하였다. 실험 결과, 영지버섯의 ether 분획에서는 혈청중 GOT, GPT의 활성과 triglyceride의 함량에 대해 silymarin보다 우수한 효과를 보였으며, 70% MeOH 추출물은 silymarin에 미치지 못했다.

• Journal of Radiation Protection and Research
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• v.29 no.4
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• pp.251-256
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• 2004

CsI(Tl), $CdWO_4(CWO),\;Bi_4Ge_3O_{12}(BGO)\;and\;Gd_2SiO_5:Ce(GSO)$ scintillators were studied to manufacture a phoswich detector. The maximum wavelengths of the CsI(Tl), CWO, BGO and GSO scintillators are 550 nm, 475 nm, 490 nm and 440 nm for the radioluminescence, and the absolute light outputs of the CsI(Tl), CWO, BGO and GSO scintillators are 54890 phonon/MeV, 17762 phonon/MeV, 8322 phonon/MeV and 8932 phonon/MeV with a neutral filter, and the decay time of the CsI(Tl), CWO, BGO and GSO scintillators is $1.3{\mu}s,\;8.17{\mu}s$, 213 ns and 37 ns by a single photon method. The phoswich detector which was manufactured with plastic and CsI(Tl) scintillators could separate the ${\beta}$ particle and ${\gamma}$ ray. The phoswich detector could also measure the pulse height spectra of the ${\beta}$ particle and ${\gamma}$ ray by a PSD method.

• Archives of Pharmacal Research
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• v.22 no.4
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• pp.423-427
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• 1999

A study was carried out to evaluate flavonol glycosides in leaves of Symplocarpus renifolius (Araceae). From the water fraction of the MeOH extract, three new flavonol glycosides were isolated along with three known compounds, Kaempferol-3-O-$\beta$-glucopyranosyl-($1{\rightarrow}2$)-$\beta$-D-glucopyranosyl-7-O-$\beta$-D-glucopyranoside, quercetin-3-O-$\beta$-D-glucopyranosy-1-($1{\rightarrow}2$)-$\beta$-D-glucopyranoside, and caffeic acid. The structures of the new flavonol glycosides were elucidated by chemical and spectral analyses a quercetin-3-O-$\beta$-D-glucopyranosyl-($1{\rightarrow}2$)-$\beta$-D-glucopyranosyl-7-O-$\beta$-D-glucopyranoside, isorhamnetin-3-O-$\beta$-D-glucopyranosyl-(1 2)-$\beta$-D-glucopyranosyl-7-O-$\beta$-D-glucopyranosdie, and quercetin-3-O$\beta$-D-glucopyranosyl-($1{\rightarrow}2$)-$\beta$-D-glycopyranosyl-7-O-($6^{IIII}$-trans-caffeoyl)-$\beta$-D-glucopyranoside.

• Journal of the Korean Vacuum Society
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• v.6 no.3
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• pp.249-254
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• 1997

We investigated characteristics of Fe-doped semi-insulating InP by means of photoreflectance(PR) measurement. The band gap energy($E_0$) and broadening parameter($\Gamma$) from PR signals at 300K are 1.336 eV and 11.2 meV, respectively. As the temperature is decreased from 300 to 80 K, PR signals are varied from an overlapped shape of exciton and 2-dimensional band gap transitions(300 K) to that of exciton transition(80 K). We calculated Varshni coefficient($\alpha=0.94\pm$0.07 meV/K, $\beta=587\pm$35.2 K) and Bose-Einstein coefficient ($a_B=33.6{\pm}2.02meV$ , $\theta=165\pm$33K). After annealing of isothermal and isochronism crystallinity of InP is found to be excellent when annealed at $300^{\circ}C$ for 10~20 min, qualitatively.

• Korean Journal of Crystallography
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• v.15 no.2
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• pp.83-87
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• 2004

An organometallic complex. $Me_2Pt(PPh_2CH_2C(t-Bu)=N-N=CMe(2-py)-\kappa^2N,P)$ was synthesized from phosphinohydrazone $Ph_2PCH_2C(t-Bu)=NNH_2$, 2-acetylpyridine, and $[PtMe2({\mu}-SMe_2)]_2$. The molecular structure of this complex has been determined by X-ray diffraction. Crystallographic data: monoclinic, space group $P2_1/n,\;a=11.6926(7)\;{\AA},\;b=15.6607(19)\;{\AA},\; c=14.6125(6)\;{\AA},\;\beta=93.018(4)^{\circ},\;Z=4,\;V=2672.0(4)\;{\AA}^3$. The structure was solved by direct methods and refined by full-matrix least-squares methods to give a model with a reliability factor R = 0.0363 for 5238 reflections.

• Journal of the Korean Chemical Society
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• v.28 no.3
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• pp.155-162
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• 1984

Kinetic studies for the nucleophilic substitution reactions of para-substituted benzyl bromides and benzyl iodide with anilines were carried out in MeOH-MeCN mixtures at 35.0$^{\circ}$C. Hammett $ {\rho}_N,\;{\rho}_C$, Bronsted $ {\beta}$ and solvatochromic correlation coefficient a, s values were determined in order to clarify the transition state variations caused by changing nucleophiles, substituents, leaving group and solvents. The results of solvatochromic equation showed that ${\pi}^{ast}$effect was a dominant factor for the reaction systems studied. It was shown that the reaction proceeds via the dissociative $S_N$2 mechanism using the potential energy surface model approach. The potential energy surface model approach however failed to account for the transition state variation due to leaving group changes. The quatum mechanical approach showed that kinetic results were consistent with proposed dissociative $S_N$2 mechanism.

• Journal of the Korean Chemical Society
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• v.29 no.1
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• pp.45-51
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• 1985

Rate constants and activation parameters for the methanolysis of t-butyl halide (t-BuCl, t-BuBr, t-BuI) in various MeOH-DMSO mixtures were measured by conductometric method. Taft's solvatochromic parameters, such as polarity-polarizability(SPP's), ${\pi}^{\ast}$, hydrogen bond donor (HBD) acidity, ${\alpha}$, and hydrogen bond acceptor (HBA) basicity, ${\beta}$ of the solvents, were determined by the so called solvatochromic method using five indicators. The variation of methanolysis rate with the solvent composition was discussed on the basis of the activation parameters and the correlation of the rates with the solvatochromic parameters. It is concluded that the polarity-polarizability, HBD acidity and HBA basicity of the mixtures had an effect on the ionization of t-butyl halide cooperatively, also that the specific interaction between the leaving groups and the solvents, such as ion-dipole and hydrogen bond acceptor-donor interaction, is the most important factor of solvent effects on the stabilization of transition states.

• YAKHAK HOEJI
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• v.43 no.1
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• pp.5-10
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• 1999

As one of the serial studies on the specific and indigenous plants of Mt. Chiri the constituents of aerial part from filipendula formosa (Rosaceae) were investigated. From of the MeOH extract, five flavonol glycosides, kaempferol-3-O-$\beta$-D-galactopyranoside, querecetin-3-O-$\beta$-D-galactopyranoside, quercetin-3-O-$\alpha$-Lrhamopyranosyl (1 6)-$\beta$-D-galactopyranoside, kaempferol-3-O-$\alpha$-L-rhamnopyranosyl (1 6)-$\beta$-D-galactopyranoside and quercetin-7-O-$\beta$-D-glucopyranosy-3-O-$\beta$-D-galactopyranoside were isolated by column chromatographic separation using Amberlite XAD-2 and Sephadex LH-20, and identified physicochemical evidences (IR, FAB-Mass, $^1H,{\;}^{13}C-NMR$).

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3279-3282
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• 2010

The reaction rates of 4-X-2,6-dinitrochlorobenzenes (X = $NO_2$, CN, $CF_3$) with Y-substituted benzylamines (Y = p-$OCH_3$, p-$CH_3$, H, p-Cl) in MeOH-MeCN mixtures were measured by conductometry at $25^{\circ}C$. It was observed that the rate constant increased in the order of X = $NO_2$ > CN > $CF_3$ and in the order of Y = p-$OCH_3$ > p-$CH_3$ > H > p-Cl. When the solvent composition was varied, the rate constant increased in the order of 100% MeOH < 50% (v/v) MeOH-MeCN < 100% MeCN. These results may be ascribed to the formation of hydrogen bonds between the alcoholic hydrogen and nitrogen of benzylamines in groud state (GS). We conclude that the reaction takes place via $S_NAr$ base on the transition state parameters ${\rho}x$, ${\rho}Y$, $\beta_{nuc}$, and solvent effects.

• Journal of Microbiology and Biotechnology
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• v.29 no.7
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• pp.1137-1143
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• 2019

Hepatitis E virus (HEV) accounts for 20 million infections in humans worldwide. In most cases, the infections are self-limiting while HEV genotype 1 infection cases may lead to lethal infections in pregnant women (~ 20% fatality). The lack of small animal models has hampered detailed analysis of virus-host interactions and HEV-induced pathology. Here, by employing a recently developed culture-adapted HEV, we demonstrated that methyltransferase, a non-structural protein, strongly inhibits melanoma differentiation-associated gene 5 (MDA5)-mediated activation of type I interferon responses. Compared to uninfected controls, HEV-infected cells display significantly lower levels of $IFN-{\beta}$ promoter activation when assessed by luciferase assay and RT-PCR. HEV genome-wide screening showed that HEV-encoded methyltransferase (MeT) strongly inhibits MDA5-mediated transcriptional activation of $IFN-{\beta}$ and $NF-{\kappa}B$ in a dose-responsive manner whether or not it is expressed in the presence/absence of a tag fused to it. Taken together, current studies clearly demonstrated that HEV MeT is a novel antagonist of MDA5-mediated induction of $IFN-{\beta}$ signaling.