• 제목/요약/키워드: Radical mechanism

검색결과 502건 처리시간 0.033초

티안트렌 양이온 자유라디칼 과염소산염과 N-아릴벤젠술폰아미드 및 N-아릴-p-톨루엔술폰아미드의 반응. 5-(p-N-아릴술폰아미드페닐)티안트렌이움 과염소산염과 5-(p-N-아릴-p-톨루엔술폰아미드페닐)티안트렌이움 과염소산염의 합성 (Reactions of Thianthrene Cation Radical Perchlorate with N-Arylbenzene- and N-Aryl-p-toluenesulfonamides. Synthesis of 5-(p-N-Arylbenzenesulfonamidephenyl)- and 5-(p-N-Aryl-p-toluenesulfonamidophenyl)thianthrenium Perchlorate)

  • 김성훈;김경태
    • 대한화학회지
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    • 제25권6호
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    • pp.383-389
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    • 1981
  • 티안트렌 양이온 자유라디칼 과염소산염은 p-톨루엔술포아니리드, 벤젠술폰아니리드, N-(2-메틸페닐)벤젠술폰아미드, N-페닐-p-톨루엔술폰아닐리드와 같은 N-아릴술폰아미드와 반응하여 각각 5-(p-N-p-톨루엔술폰아미도페닐)티안트렌이움 과염소산염(1a), 5-(p-N-벤젠술폰아미도페닐)티안트렌이움 과연소산염(1b), 5-(4-N-벤젠술폰아미도-3-메틸페닐)티안트렌이움 과염소산염(1c), 5-(p-N-페닐-N-p-톨루엔술폰아미도페닐)티안트렌이움 과염소산염(1d)을 준다. 한편 1d는 티안트렌 양이온 자유라디칼과 다시 반응하여 이과염소산염(1e)을 생성한다. 1a∼1e의 구조는 아세트아니리드와의 반응생성물인 5-(p-아세트아미도페닐)티안트렌이움 과염소산염과 매우 비슷하다. 그러나 두 반응의 양 관계에서 상이한 점은 술폰아미드와의 반응이 단일 메카니즘으로 진행되지 않음을 암시한다.

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번행초 추출물의 항산화 및 항염증 효과 (Antioxidant and Anti-inflammatory Activities of Tetragonia tetragonoides Water Extract)

  • 공지현;이기연;노대현;이장천;안원근;이부균
    • 대한한의학방제학회지
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    • 제28권2호
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    • pp.137-145
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    • 2020
  • Objectives : Tetragonia tetragonioides is one of the traditional herbal medicines that can be used to protect the stomach and treat cancer. However, its mechanism of overcoming gastrointestinal disorders is unclear. In this study, we investigated antioxidant and anti-inflammatory effects of Tetragonia tetragonioides Water Extract (TTWE) on RAW264.7 cells. Methods : The cell viability by TTWE was measured by using MTT assay. The free radical scavenging ability and cytokine production were analyzed by using ELISA Kit. SPSS version 25 was used for statistical analysis. Results : According to the results of this study, the cell viability measurement of TTWE significantly affected the cell viability. The radical scavenging ability of TTWE showed the highest effect compared to the positive control group when the concentration was 3.1-12.5 ㎍/ml, and significantly inhibited NO production induced by LPS. In addition, the inhibitory effect of TTWE on the production of IL-6 and TNF-α induced by LPS was significant at both TTWE concentrations of 12.5 ㎍/ml [p <0.01 (IL-6), p <0.05 (TNF-α)]. Conclusion : In conclusion, it is suggested that the antioxidant function of Tetragonia tetragonioides Water Extract could be used to prevent and treat inflammatory diseases.

창출도인탕가미방(蒼朮桃仁湯加味方)이 류마토이드 관절염에 미치는 실험적 연구 (A Study on the Effect of Changchuldointanggami-bang(Cāngzhútáoréntāngjiāwèi-fāng) in Rheumatoid Arthritis)

  • 박은숙;윤일지
    • 한방재활의학과학회지
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    • 제19권4호
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    • pp.1-18
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    • 2009
  • Objectives : This study was carried out to understand the immune responses of the Changchuldointanggami-bang(after referred to CDIT) on antioxidants, THP-1 cell and rheumatoid arthritis in Collagen-induced Arthritis(CIA) mice. Methods : The antioxidative effect of CDIT on DPPH free radical and SOD-like activity was measured. CDIT was administered to THP-1 cell, cytokine and mRNA associated with inflammation were measured. CDIT was orally administered to mice with arthritis by collagen II and then cytokine, PBMC in the serum were measured. Results : 1. The scavenging activity of CDIT on DPPH free radical was dose-dependent. 2. The effect of CDIT on SOD-like activity was dose-dependent. 3. The production of $IL-1{\beta}$, IL-6, $TNF-{\alpha}$ was decreased significantly in THP-1 cell. 4. The expression of $IL-1{\beta}$ mRNA, IL-6 mRNA, $TNF-{\alpha}$ mRNA were decreased significantly in THP-1 cell. 5. $IL-1{\beta}$, IL-6, $TNF-{\alpha}$ were decreased significantly in the serum of CIA mice. 6. CD3+, CD4+, CD8+ were increased significantly, but CD3+/CD69+, CD3+/CD49b+, B220+/CD23+ were decreased significantly in PBMC of CIA mice. Conclusions : Taking all these observations into account, CDIT is considered to be effective in rheumatoid arthritis. Therefore we have to survey continuously in looking for the effective substance and mechanism in the future.

첨가제를 이용한 액체연료의 열안정성 향상 (Thermal Stability Improvement of Liquid Fuel by Using Some Additives)

  • 박선희;김중연;전병희;한정식;정병훈;김성현
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2010년도 제35회 추계학술대회논문집
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    • pp.294-299
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    • 2010
  • 본 연구의 목적은 열안정성을 향상시키는 첨가제 (열안정제)를 이용하여 exo-tetrahydrodicyclopentadiene (exo-THDCP, $C_{10}H_{16}$)의 열안정성을 향상시키는 것이다. 실험은 반응 진행 중 미량의 시료 추출이 가능한 회분식 반응기에서 수행되었다. 추출한 시료를 gas chromatography-mass spectrometry (GC-MS)를 이용해 성분 분석하여 첨가제 성능-exo-THDCP의 열분해성-을 확인하고, 반응시간에 따른 exo-THDCP의 분해생성물의 성분 및 조성 변화를 통해 첨가제의 작용 메커니즘을 규명하였다. 열안정제로써 수소공여체를 사용하여 실험한 결과 1,2,3,4-tetrahydroquinoline (THQ), benzyl alcohol (BnOH) 등을 첨가하였을 때 exo-THDCP의 열안정성이 향상되었다. 이러한 수소공여체 물질들은 개시반응이 진행된 exo-THDCP 라디칼에 수소원자 (hydrogen radical)를 제공함으로 라디칼의 반응성을 완화시켜 1차 생성물의 활성을 감소시키어 2차생성물질인 $C_{11}$ 이상 생성물의 발생을 감소시키는 것으로 밝혀졌다.

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여주의 페놀성 화합물인 Protocatechuic Acid의 산화적 스트레스 개선 및 신경염증 보호 효과 (Protective Effect of Protocatechuic Acid, Phenolic Compound of Momordica Charantia, against Oxidative Stress and Neuroinflammation in C6 Glial Cell)

  • 김지현;최정란;조은주;김현영
    • 한방비만학회지
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    • 제20권1호
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    • pp.10-19
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    • 2020
  • Objectives: Oxidative stress-mediated neuroinflammation has been supposed as a crucial factor that contributes to the pathogenesis of many neurodegenerative diseases. In this study, we aimed to investigate the protective activity against oxidative stress and neuroinflammation of protocatechuic acid (PA), active phenolic compound from Momordica Charantia. Methods: Protective activity of PA from oxidative stress was performed under in vitro conditions. Our study investigated the protective mechanism of PA from neuroinflammation in cellular system using C6 glial cell. To investigate the improvement the effects on oxidative stress and neuroinflammation, we induced oxidative stress by H2O2 (100 μM) stimulation and induced neuroinflammation by treatment with lipopolysaccharide (LPS) (1 ㎍/mL) and interferon-gamma (IFN-γ) (10 ng/mL) in C6 glial cells. Results: PA showed strong radical scavenging effect against 1,1-dipenyl-2-picrylhydrazyl, hydroxy radical (·OH) and nitric oxide (NO). Under oxidative stress treated by H2O2, the result showed the increased mRNA expressions of oxidative stress markers such as nuclear factor-kappaB (NF-κB), cyclooxygenase (COX-2) and inducible nitric oxide (iNOS). However, the treatment of PA led to reduced mRNA expressions of NF-κB, COX-2 and iNOS. Moreover, PA attenuated the production of interleukin-6 and scavenged NO generated by both endotoxin LPS and IFN-γ together. Furthermore, it also reduced LPS and IFN-γ-induced mRNA expressions of iNOS and COX-2. Conclusions: In conclusion, our results collectively suggest that PA, phenolic compound of Momordica Charantia, could be a safe anti-oxidant and a promising anti-neuroinflammatory molecule for neurodegenerative diseases.

Biphenyl Dimethyl Dicarboxylate가 간내 Cytochrome $P_{450}$ 1A1과 2Bl 및 $CCl_4$ 유도 간독성에 미치는 영향 (Effect of Biphenyl Dimethyl Dicarboxylate on Cytochrome $P_{450}$ 1A1 and 2B1 and ${CCl_4}-Induced$ Hepatotoxicity in Rat Liver)

  • 김순선;오현영;김학림;양지선;김동섭;신윤용;최기환
    • 약학회지
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    • 제43권6호
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    • pp.827-833
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    • 1999
  • In this study, we have investigated the effect of Biphenyl Dimethyl Dicarboxylate (DDB), a synthetic analogue of Schizandrin C isolated from Schizandrae Fructus on cytochrome $P_450$ lAl and 2Bl, and the protective mechanism against $CCl_4-induced$ hepatotoxicity in rat liver. After DDB was administered into male rats for different periods of time (1~7 days) and with different doses (25, 50, 100 and 200 mg/kg), mRNA levels of CYPlAl were measured by polymearse chain reaction (PCR) and assayed the activities of CYPlAl specific ethoxyresorufin-O-dealkylase (EROD) and CYP2Bl specific benzyloxyresorufin-O-dealkylase (BROD). DDB treatment resulted in increase in CYP2Bl mRNA level and BROD activity, whereas there was no change in CYPlAl mRNA level and EROD activity. This effect of DDB was time-and dose-dependent and reached maximal level by 3 day and 200 mg/kg treatment. In addition, rats were pre-treated with DDB at doses of 25, 50 or 100 mg/kg daily for 4 days, 3-hr after final treatment on the 4th day, $CCl_4$ 0.3ml/kg was intraperitonially injected into the rats to examine the effect of DDB on $CCl_4-induced$ hepatic injury. Serum levels of ALT and AST were determined and histopathological examination was done in rat liver. Furthermore, we have measured hepatic microsomal malondialdehyde(MDA) level, a parameter of lipid peroxidation. Based on serum ALT level and lipid peroxidation, pretreatment of DDB, 50 mg/kg appeared the most protective effect against $CCl_4-induced$ heapatotoxity. These results indicate that DDB stimulates CYP2Bl mRNA level and BROD activity in time and dose dependent manner and suggest that protective effect of DDB on $CCl_4-induced$ hepatotoxicity may be mediated through free radical scavenging.

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고려인삼의 방사선 방어효과에 대한 연구현황과 전망 (Radioprotective Potential of Panax ginseng: Current Status and Future Prospectives)

  • 남기열;박종대;최재을
    • 한국약용작물학회지
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    • 제19권4호
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    • pp.287-299
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    • 2011
  • Pharmacological effects of Panax ginseng have been demonstrated in cardiovascular system, endocrine secretion and immune system, together with antitumor, anti-stress and anti-oxidant activities. Modern scientific data show protective effect of ginseng against bone marrow cell death, increased survival rate of experimental animals, recovery of hematopoietic injury, immunopotentiation, reduction of damaged intestinal epithelial cells, inhibition of mutagenesis and effective protection against testicular damages, caused by radiation exposure. And also, ginseng acts in indirect fashion to protect radical processes by inhibition of initiation of free radical processes and thus reduces the radiation damages. The research has made much progress, but still insufficient to fully uncover the action mechanism of ginseng components on the molecule level. This review provides the usefulness of natural product, showing no toxic effects, as an radioprotective agent. Furthermore, the further clinical trials on radioprotection of ginseng need to be highly done to clarify its scientific application. The effective components of ginseng has been known as ginsenosides. Considering that each of these ginsenosides has pharmacological effect, it seems likely that non-saponin components might have radioprotective effects superior to those of ginsenosides, suggesting its active ingredients to be non-saponin series. These results also show that the combined effects of saponin and non-saponin components play an important role in the radioprotective effects of ginseng.

가미사물탕(加味四物湯)이 고혈압 병태 모델과 활성산소에 미치는 영향 (Effect of Kamisamul-tang on Hypertension and Free Radical)

  • 송낙근;구영선;김동희
    • 동의생리병리학회지
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    • 제20권6호
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    • pp.1485-1496
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    • 2006
  • Various kinds of related parameters on hypertension such as anti-oxygen effect, ACE, weight of body, hwart and kidney, blood pressure, heartbeat rates, contents of aldosterone, catecholamine, change rates, of plasma constituents, uric acid, BUN, creatinine were determined to verify the effects on hypertension by Kamisamul-tang (KSMT). And the results are concluded as follows. KSMT did not show any cytotoxicity at the range of concentration (1-250 ${\mu}g/m{\ell}$) on the human fibroblast cell (hFCs). KSMT decreased the production of reactive oxygen species (ROS) and DPPH generation depending on the concentration. KSMT significantly inhibited angiotensin converting enzyme(ACE) activity depending on the concentration compared with control. KSMT maintained body weight of body, heat and kidney nearly normal group in hypertensive rat induced by DOCA-salt. KSMT significantly blood pressure and heart beat rate compared with control in hypertensive rat induced by DOCA-salt. KSMT significantly decreased aldosterone, dopamine, norepineph- rine, epinephrine compared with control in hypertensive rat induced by DOCA-salt. KSMT significantly decreased the level of potassium and cloride compared with control wheareas increased that of calcium significantly in hypertensive rat induced by DOCA-salt. KSMT significantly decreased the level of uric acid and BUN compared with control in hypertensive rat induced by DOCA-salt. It is verified experimentally tat Kamisamultang(KMST) which has been used broadly as a clinical therapeutics in oriental medicine is effective for anti-hypertension mechanism. And it could be applied to develope the reliable prescriptions for anti-hypertension in the future.

Gas Phase Thernal cis-trans Isomerization Reaction of 1-Bromopropene

  • Huh, D- Sung;Um, Jae-Young;Yun, Sun-Jin;Choo, Kwang-Yul;Jung, Kyung-Hoon
    • Bulletin of the Korean Chemical Society
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    • 제11권5호
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    • pp.391-395
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    • 1990
  • The kinetics of thermnal cis-trans isomerization reaction of 1-bromopropene(1-BP) was studied at temperatures from 620.8 to 753.15 K over the pressure range 0.17-50.3 Torr. Both the inhibition effect by cyclohexene or propene and the catalytic effect by HBr showed a radical process as the main mechanism of the isomerization. In the suppression of the radical process by the inhibitors, the molecular process also contributed to overall reaction rate. The reactions demonstrated the first order kinetics under both uninhibited and inhibited conditions and could be represented by the expressions (R = 1.987 cal/mol/K) $k_{un}/s^{-1} = (3.45{\pm}1.50){\times}10^{11}$exp$[(- 48100{\pm}2000)/RT]\;k_{ink}/s^{-1} = (2.98{\pm}1.40){\times}10^{12}$exp$[(- 55800{\pm}1800)/RT]$> where $k_{un}$ is the observed rate constant of cis-1-bromopropene(1-B$P_c$) to trans-1-bromopropene(1-B$P_t$) under uninhibited condition at initial pressure of 50 Torr and $k_{ink}$ is the rate constant under maximal inhibition by cyclohexene. The ratio of rate constants for bromine atom elimination from the allylic hydrogen of reactant(1-BP) and from the inhibitors, propene and cyclohexene, were measured from the observed rates of the uninhibited and inhibited reactions. The inhibition efficiencies of cyclohexene and propene were compared kinetically from the rate constants and shown to give good agreement with the previous results reported from other alkyl bromide pyrolyses.

Neuroprotective mechanisms of dieckol against glutamate toxicity through reactive oxygen species scavenging and nuclear factor-like 2/heme oxygenase-1 pathway

  • Cui, Yanji;Amarsanaa, Khulan;Lee, Ji Hyung;Rhim, Jong-Kook;Kwon, Jung Mi;Kim, Seong-Ho;Park, Joo Min;Jung, Sung-Cherl;Eun, Su-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • 제23권2호
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    • pp.121-130
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    • 2019
  • Glutamate toxicity-mediated mitochondrial dysfunction and neuronal cell death are involved in the pathogenesis of several neurodegenerative diseases as well as acute brain ischemia/stroke. In this study, we investigated the neuroprotective mechanism of dieckol (DEK), one of the phlorotannins isolated from the marine brown alga Ecklonia cava, against glutamate toxicity. Primary cortical neurons ($100{\mu}M$, 24 h) and HT22 neurons (5 mM, 12 h) were stimulated with glutamate to induce glutamate toxic condition. The results demonstrated that DEK treatment significantly increased cell viability in a dose-dependent manner ($1-50{\mu}M$) and recovered morphological deterioration in glutamate-stimulated neurons. In addition, DEK strongly attenuated intracellular reactive oxygen species (ROS) levels, mitochondrial overload of $Ca^{2+}$ and ROS, mitochondrial membrane potential (${\Delta}{\Psi}_m$) disruption, adenine triphosphate depletion. DEK showed free radical scavenging activity in the cell-free system. Furthermore, DEK enhanced protein expression of heme oxygenase-1 (HO-1), an important anti-oxidant enzyme, via the nuclear translocation of nuclear factor-like 2 (Nrf2). Taken together, we conclude that DEK exerts neuroprotective activities against glutamate toxicity through its direct free radical scavenging property and the Nrf-2/HO-1 pathway activation.