• 대한화학회지
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• 제18권4호
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• pp.251-258
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• 1974

아세톤, 아세토니트릴, 메탄올, 에탄올 등의 용매에서 치환염 벤조일과 파라니트로아닐린과의 친핵치환반응에 대한 속도상수를 전기 전도도법으로 구하고 활성화 파라미터를 계산하였다. 결과로 반양성자 용매보다는 양성자성 용매에서 반응속도가 빨랐고 같은 성질의 용매에서는 유전상수가 큰 쪽이 반응이 더 빨랐으며 각 용매에 있어서의 Hammett도시는 정의 기울기를 가진 직선을 나타내었으며, 반응은 첨가-제거 메카니즘으로 일어났다.

• Bulletin of the Korean Chemical Society
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• 제18권11호
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• pp.1186-1191
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• 1997

Solvolyses of methanesulfonyl chloride (CH3SO2Cl) in water and methanol have been studied theoretically using ab initio self-consistent reaction field (SCRF) molecular orbital method. All stationary structures including transition state on the potential energy surface in solution have been found and compared with the gas phase structures. The overall reaction occurs via a concerted SN2 mechanism with a non-cyclic trigonal bipyramidal transition state, and the activation barrier is lowered significantly in solution. The transition state for the hydrolysis reaction is looser than that for the methanolysis reaction, and this is in accord with the experimental findings that an SN2 type mechanism, which is shifted toward an SN1 process or an SAN process in the hydrolysis and alcoholysis reaction, respectively, takes place. The catalytic role of additional solvent molecules appears to be a purely general-base catalysis based on the linear transition structures. Experimental barrier can be estimated by taking into account the desolvation energy of nucleophile in the reaction of methanesulfonyl chloride with bulk solvent cluster as a nucleophile.

• 약학회지
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• 제50권6호
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• pp.367-371
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• 2006

Phellinus pini (Hymenocaetaceae) has been used for the immunomodulating activity hypolipidemic effect, gastric cancer non-insulin dependant diabetes, diarrhea, and menstrual irregularity. From the screening of each fraction for the inhibitory activity of NO production in lipopolysaccaride (LPS) activated RAW 264.7 cells, methanol extract of Phellinus pini and hexane soluble fraction exhibited inhibition of NO production compared with LPS control without toxicity. The hexane soluble fraction showed dose dependent inhibition of NO production. According to activity guided fractionation, the active hexane fr. was repeatedly chromatographed over silica gel, ergosta-4,6,8(14),22- tetraen-3-one was isolated. The compound inhibited NOS activation (IC$_{50}$ = 29.7 uM) and NO production of activated macrophage at 30 uM.

• Bulletin of the Korean Chemical Society
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• 제8권4호
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• pp.230-232
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• 1987

Nitrogen-14 quadrupolar relaxation has been observed in the amino proton nmr spectra of TA in acetone and methanol solutions over the temperature range $-83^{\circ}C\; to\;+35^{\circ}C.$ The proton nmr lineshapes were analyzed to yield a $^{14}N$ spin lattice relaxation time $(T_1)_N$ as a function of temperature. Activation energies and correlation times at $25^{\circ}C$ for the molecular reorientation in the two solution phases have been calculated and the results are discussed.

• 한국식품영양과학회지
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• 제37권3호
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• pp.269-275
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• 2008

본 연구에서는 아보카도의 기능성 소재로서의 이용가능성을 알아보기 위해, 아보카도의 과육, 씨, 껍질을 각각 분리한 후 추출물을 제조하여 이들 각각의 항산화 효과를 연구하였고, 인간유래 유방암 세포주인 MDA-MB-231 세포주를 사용하여 항암활성을 살펴보았다. 아보카도 과육과 씨 및 껍질의 메탄올 추출물에 존재하는 총 폴리페놀 및 플라보노이드 함량을 측정한 결과 총 폴리페놀 함량은 아보카도 과육과 씨 및 껍질 추출물이 각각 13.89, 137.2, $223.45{\mu}g/mg$으로 아보카도 껍질 추출물에서 가장 높게 나타났고, 총 플라보노이드 함량에서도 각각 4.03, 5.69, $13.6{\mu}g/mg$으로 폴리페놀 함량보다는 다소 낮게 나타났지만 총 플라보노이드 함량 역시 껍질에서 가장 높게 나타났다. 각 시료의 DPPH 소거활성을 농도별로 측정한 결과, 아보카도 껍질 추출물이 $5{\mu}g/mL$에서 60.4%로 껍질 추출물이 가장 우수한 항산화능을 보였다. 또한 $ABTS{\cdot}^+$ 소거활성을 trolox, BHA, ascorbic acid와 비교하여 측정한 결과, 아보카도 껍질 추출물은 $10{\mu}g/mL$에서 60.4%의 소거활성을 보였고, DPPH 소거활성과 동일하게 껍질 추출물에서 가장 우수한 소거활성능을 보였다. 아보카도 씨, 껍질 추출물이 apoptosis를 유도하는지를 관찰한 결과 씨, 껍질 추출물 모두 caspase-3, PARP 단백질들의 발현을 유도하였고, 이들은 모두 $200{\mu}g/mL$의 농도에서 가장 높게 발현되는 것을 확인하였다. 또한 DNA 분절 현상을 관찰한 결과 씨 추출물에서는 100, $200{\mu}g/mL$ 농도에서, 껍질 추출물에서 10, 50, 100, $200{\mu}g/mL$의 농도에서 DNA 분절화 현상이 일어난 것을 관찰하였다. 결과적으로 아보카도 씨와 껍질 추출물은 apoptosis를 유도하는 유전자인 caspase에 영향을 미치는 것으로 보이며, 순차적으로 DNA 분절을 활성화시켜 호르몬 비의존성 유방암 MDAMB-231 세포주의 apoptosis의 유도에 큰 영향을 미치는 것으로 나타났다.

• 대한본초학회지
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• 제25권4호
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• pp.103-112
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• 2010

Objective : The aim of this study was to determine whether methanol extract of Do-Ki-Tang (DKT) inhibit free radical generation and production of nitrite an index of NO, $PGE_2$, iNOS, COX-2 and pro-inflammatory cytokines such as TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and MCP-1 in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Methods : Cytotoxic activity of extract on RAW 264.7 cells was measured using 5-(3-caroboxymeth-oxyphenyl)-2H-tetra-zolium inner salt (MTS) assay. The expression level of inflammatory response-related proteins was confirmed by western blot. The production of proinflammatory cytokines was measured by ELISA. Results : Our results indicated that DKT scavenged DPPH radical and nitric oxide in vitro. Moreover, DKT significantly inhibited the LPS-induced NO, $PGE_2$ production and iNOS, COX-2 expression accompanied by an attenuation of TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and MCP-1 formation in macrophages. Furthermore, DKT treatment also blocked LPS-induced intracellular ROS production and the activation of NF-${\kappa}B$ and MAPKs. Conclusion : Our data suggest that the anti-inflammatory effect of DKT is mediated through down-modulation of pro-inflammatory mediators and cytokines by blocking the signaling pathways of NF-${\kappa}B$ and MAPKs. These inhibitory effects by DKT represent a potential therapeutic approach to the treatment of inflammatory diseases.

• 대한한의학회지
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• 제25권2호
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• pp.1-8
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• 2004

Objectives : This study was performed to investigate the effects of Smilacis GlabraeRhizoma on antioxidation and antimicrobial activity. Methods : In this study, we investigated the effects of peroxide radicals on hydrogen donating activity and linoleic acid, and the MDA contents on the hepatic lipids of rats, via methanol extractions and subfractions of Smilacis Glabrae Rhizoma. Results : 1. Hydrogen donating activity was very great for the radical scavenging effects, depending on the additional concentration at the fraction level of chloroform and ethyl acetate. 2. The peroxide radicals in linoleic acid were lower depending on the additional concentration, at the fraction level of ethyl acetate, than the controls. We concluded that both had significant anti-oxidation effects. 3. MDA contents of the hepatic lipid had also inhibition effects on lipid radicals, in proportion to the concentration of n-hexane, chloroform, and ethyl acetate fraction level. 4. After extracting Smilads Glabrae Rhizoma with 80% methanol, we experimented with the extracts the antibiosis each concentration, for 5 bacilli, Bacilus subtilis, staphylococcus aureus, Escherichia coli, Salmonela typhimurium, and Alcaligenes faecalis. While the effects showed differentiations by concentration, they had usually the significant inhibition effect for the multiplication at 37.5~75ug/ml. To identify the effective constituents, we identified the antibiosis of the fractions assaying cyclically hexane, chloroform, ethyl acetate, and butanol. The result showed that antimicrobial activation of both Gram-positive and Gram-negative bacillus except for E. coli was measured highest at the fraction level of BuOH and water. Conclusions : This result suggest that the extractions of Smilacis Glabrae Rhizoma, at ethyl acetate fraction, had significant anti-oxidation effects and at BuOH and water fraction had relatively strong antimicrobial activity against Bacilus subtilis, staphylococcus aureus, Salmonela typhimurium, and Alcaligenes faecalis.

• 한국식품영양과학회지
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• 제20권3호
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• pp.260-265
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• 1991

Salmonella/microsome assay system을 이용하여 N -nitrosodimethylamine (NDMA)의 돌연변이유발성을 검토하는 효과적인 방법과 비타민 C가 NDMA자체의 돌연변이유발과 nitrite와 2급아민으로부터의 NDMA 생성에 미치는 영향을 연구하였다. NDMA를 활성화시키기 위한 S9중 Aroclor1254로 induce시킨 hamster S9이 가장 효과가 있었으며 Aroclor 1254나 phenobarbital로 induce시킨 rat 59 mix에 의하여서는 활성화가 약하였다. DMSO와 ethanol에 NDMA를 녹였을 때는 돌연변이유발실험에서 저해효과가 나타났으나 phosphate buffer(pH 7. 4), 증류수, 95% methanol, Tween 80 + water(l : 4)는 저해 효과가 없었다. 비타민 C는 이미 생성환 NDMA에 대해서는 돌연변이 유발저해 효과를 나타내지 않았지만 nitrite와 2급 아민(dimethylamine)으로 부터의 NDMA 생성은 크게 저해하였다. 반응물에 비타민C를 첨가한 경우 Salmonella typhimurium TAl00의 revertant 수가 spontaneous숫자 수준으로 감소되었으며 HPLC를 이용한 NDMA의 분석에서도 거의 95% 까지의 정량적인 감소를 관찰할 수 있었다.

• Nutrition Research and Practice
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• 제8권4호
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• pp.352-359
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• 2014

BACKGROUND/OBJECTIVES: In this study, we determined the anti-inflammatory activities and the underlying molecular mechanisms of the methanol extract from Erigeron Canadensis L. (ECM) in LPS-stimulated RAW264.7 macrophage cells. MATERIALS/METHODS: The potential anti-inflammatory properties of ECM were investigated by using RAW264.7 macrophages. We used western blot assays and real time quantitative polymerase chain reaction to detect protein and mRNA expression, respectively. Luciferase assays were performed to determine the transactivity of transcription factors. RESULTS: ECM significantly inhibited inducible nitric oxide synthase (iNOS)-derived NO and cyclooxygenase-2 (COX-2) derived PGE2 production in LPS-stimulated RAW264.7 macrophages. These inhibitory effects of ECM were accompanied by decreases in LPS-induced nuclear translocations and transactivities of $NF{\kappa}B$. Moreover, phosphorylation of mitogen-activated protein kinase (MAPKs) including extracellular signal-related kinase (ERK1/2), p38, and c-jun N-terminal kinase (JNK) was significantly suppressed by ECM in LPS-stimulated RAW264.7 macrophages. Further studies demonstrated that ECM by itself induced heme oxygenase-1 (HO-1) protein expression at the protein levels in dose-dependent manner. However, zinc protoporphyrin (ZnPP), a selective HO-1 inhibitor, abolished the ECM-induced suppression of NO production. CONCLUSIONS: These results suggested that ECM-induced HO-1 expression was partly responsible for the resulting anti-inflammatory effects. These findings suggest that ECM exerts anti-inflammatory actions and help to elucidate the mechanisms underlying the potential therapeutic values of Erigeron Canadensis L.

• 대한화학회지
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• 제27권3호
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• pp.167-177
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• 1983

물-메탄올, 물-에탄올, 물-아세톤 및 물-아세토니트릴의 2-성분 혼합용매 속에서 2-염화안트라센 술포닐의 가용매 분해반응을 전기전도도법을 써서 속도론적으로 고찰하였다. 물의 몰분률이 같은 혼합용매속에서는 쌍극자성 반양성자 용매에서 보다 양성자성 용매에서 속도가 컸으며, 물-메탄올 혼합용매에서는 실험 농도의 전체 범위에 걸쳐 물-에탄올에서 보다 항상 속도가 컸으나 아세톤과 아세토니트링의 경우에는 몰분율 0.9에서 속도의 크기가 뒤바뀌었다. 용매의 이온화 능력에 대한 반응의 감도를 나타내는 m와 전이상태에서의 물의 관여차수 n값은 모두 쌍극자성 반양성자용매에서 컸다. 이들 값과, 속도상수에서 결정한 활성화 파라미터로부터 2-염화안트라센 술포닐의 가용매분해반응은$ S_N2$ 메카니즘으로 진행된다는 것을 알았다.