• Title/Summary/Keyword: diene

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The Importance of $\pi$-Nonbonded Secondary Orbital Interaction on the Stereoselectivity in the (4+2) Cycloaddition Reactions of Allene Compounds (알렌화합물의 (4+2) 고리화반응에서 입체 선택성에 대한 $\pi$-비결합 2차 궤도함수 상호작용의 중요성)

  • Ikchoon Lee;Keun Bae Rhyu;Byung Choon Lee
    • Journal of the Korean Chemical Society
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    • v.31 no.2
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    • pp.133-142
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    • 1987
  • Stereoselectivities of (4+2) cycloaddition reactions of cyclopentadiene with the methyl-substituted allenic acids and esters were investigated by application of $\pi$-nonbonded interaction ($\pi$-NBI) theory. 2-FMO method has been found to be adequate for determination of endo selectivities of diene(LUMO)-dienophile (LUMO) interaction in the thermal reactions and diene (HOMO)-dienophile (LUMO) interaction in the Lewis acid catalyzed reactions. $\pi$-isoconjugate diene structure was formed by through-bond interaction of allene moiety with methyl group in the cumulated diene system; the methyl substituent acts as a conjugative chain and causes inter-level narrowing effect of the FMO's. In dienophiles which do not form $\pi$-isoconjugate diene system, methyl group acts merely as an electron donating group. In thermal reactions, the stereoselectivities are controlled by $\pi$-nonbonded secondary orbital interaction ($\pi$-NSOI) of methyl substituent, which behaves similarly as an ethylene molecule.

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Effect of Temperature on Composition of Monohydroperoxide Isomers Formed in Oxidation of Methyl Linoleate (Methyl Linoleate의 산화중 형성된 Monohydroperoxide 이성체들의 조성에 미치는 온도의 영향)

  • Kim, In-Hwan;Kim, Chul-Jin;Kim, Dong-Hoon
    • Korean Journal of Food Science and Technology
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    • v.28 no.3
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    • pp.440-445
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    • 1996
  • An attempt was made to study the relative composition of Monohydroperoxide isomers of methyl linoleate oxidized to different peroxide values at 60, 90, 120 and $150^{\circ}C$, respectively. HPLC was used to analyze and isolate the monohydroperoxide isomers fractionated by silica gel column after reduction with NaBH.. GC-MS was used to identify four monnhydroperoxide isomers as trimethylsilyl (TMS) in mixtures of oxidized methyl linoleate In the geometrical isomers, the proportions of 9/13-OOH-trans, trant-diene were higher than those of 9/13-OOH-cis, trans-diene at $60^{\circ}C$ and $90^{\circ}C$. However in the initial stage at $150^{\circ}C$, the proportions of 9/13-OOH-cis, trans-diene were slightly higher than those of 9/13-OOH-trans, trans-diene. In case of positional isomers, equal proportions of 9-OOH-10, 12-diene and 13-OOH-9, 11-diene were found in all samples of methyl linoleate oxidized at different temperatures and peroxide levels.

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Determination of Reactivity by MO Theory (XXIII). Substituent Effect on Regioselectivity of Diels-Alder Reactions (分子軌道論에 의한 反應性 決定 (제23보). Diels-Alder 反應의 配向性에 미치는 置換基 效果)

  • Ikchoon Lee;Eun Sook Han;Keun Bae Rhyu
    • Journal of the Korean Chemical Society
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    • v.26 no.1
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    • pp.7-17
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    • 1982
  • In order to predict substituent and Lewis acid effects on the regiospecificity of the Diels-Alder reaction, and to investigate the competition for the complexation of Lewis acid between diene and dienophile, frontier orbital theory has been applied to thermal and catalyzed Diels-Alder reaction by means of CNDO/2 MO method. It has been found that: (1) Lewis acid coordinated preferentially with diene rather than dienophile when carbonyl oxygen of acetoxy substituted diene had larger negative atomic charges than that of dienophile. (2) Most of the reaction were neutral electron demand type, and hence 4-C, 2-C and quantitative secondary orbital interacion methods were generally in good accord with experiments. (3) Sulfur activated the adjacent terminal carbon atom greatly to increase diene LUMO-dienophile HOMO interaction through vacant-d-orbital participation, and played an important role in controlling regioselectivity of neutral electron demand reaction type.

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Chemical Reactivity between Ni(II)-Macrocycle Complex Ions ($NiL_m{^{2+}}$) and $CN^-$ (Ni(II)-거대고리 리간드 착이온 ($NiL_m{^{2+}}$) 과 $CN^-$ 이온간의 반응성)

  • Yu-Chul Park;Jong-Chul Byun
    • Journal of the Korean Chemical Society
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    • v.31 no.4
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    • pp.334-343
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    • 1987
  • The Chemical reactions between $NiL_m{^{2+}}\{$Ni(rac-1[14]7-diene)^{2+},\;Ni(meso-1[14]7-diene)^{2+},\;Ni(1[14]4-diene)^{2+},\;{\alpha}-Ni(rac-[14]-decane)^{2+},\;{\beta}-Ni(rac-[14]-decane)^{2+},\;and\;Ni(meso-[14]-decane)^{2+}$}\and\ CN^-$ ion were studied by the spectrophotometric method. The equilibrium constants (K_1$) for the 1:1 complex ion, $[NiL_m(CN)]^+\;with\;NiL_m{^{2+}}\;and\;CN^-$ ion were determined in the range of 3 to $25^{\circ}C$. The $K_1\;for\;Ni(rac-1[14]7-diene)^{2+},\;Ni(meso-1[14]7-diene)^{2+},\;Ni(1[14]4-diene)^{2+},\;{\alpha}-Ni(rac-[14]-decane)^{2+},\;{beta}-Ni(rac-[14]-decane)^{2+},\;and\;Ni(meso-[14]-decane)^{2+}\;at\;15^{\circ}C$ was 4.7, 5.3, 6.2, 7.5, 9.4, and 9.8, respectively. The values of $K_1$ decreased with increasing temperature. From the temperature effect on equilibrium constant ($K_1$), thermodynamic parameters $({\Delta}H^{\circ},\;{\Delta}S^{\circ},\;{\Delta}G^{\circ})$ for reaction were evaluated and the reaction of $NiL_m{^{2+}}\;and\;CN^-$ ion was exothermic. $NiL_m{^{2+}\;reacts\;with\;CN^-$ ion to give $Ni(CN)_4{^{2-}}$ ion and macrocyclic ligand $(L_m)$. The kinetics of formation of the $Ni(CN)_4{^{2-}}$ ion of varying the $[CN^-],\;[HCN],\;and\;[OH^-]$ have been investigated at 3∼$25^{\circ}C\;and\;0.5M\;NaClO_4$. Maintaining a constant $[CN^-],\;k_{obs}/[CN^-]^2$ increases linearly with increasing [HCN]. In the presence of large quantities of $[OH^-],\;k_{obs}/[CN^-]^2$ also increases linearly with $[OH^-]$. From the temperature effect on kinetic constant (k_{obs})$, parameter of activation $({\Delta}H^{\neq},\;{\Delta}S^{\neq})$ of reaction of $NiL_m{^{2+}}\;with\;CN^-$ ion were determined. For the $Ni(rac-1[14]7-diene)^{2+},\;Ni(meso-1[14]7-diene)^{2+},\;{\alpha}-Ni(rac-[14]-decane)^{2+},\;{\beta}-Ni(rac-[14]-decane)^{2+},\;and\;Ni(meso-[14]-decane)^{2+}\;series\;{\Delta}H^{\neq}$ gradually decrease as the d-d transition energy, $ν(cm^{-1})$ decrease. And the reaction of the five $NiL_m{^{2+}}\;with\;CN^-$ ion take place by way of equal paths.

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Simultaneous Determination of Valproic Acid and its Toxic Metabolites, 4-ene-VPA and 2,4-diene-VPA in Rat Plasma using a Gas Chromatographic-mass Spectrometric Method

  • Lee, Min-Sun;Lee, Young-Joo;Chung, Bong-Chul;Jung, Byung-Hwa
    • Journal of Pharmaceutical Investigation
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    • v.40 no.3
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    • pp.155-160
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    • 2010
  • A gas chromatographic-mass spectrometric (GC-MS) method was developed for the simultaneous determination of valproic acid (VPA) and its toxic metabolites, 4-ene-VPA and 2,4-diene-VPA in rat plasma. Extraction was performed in weak acidic condition (pH 5.2) to avoid degradation of 4-ene-VPA and 2,4-diene-VPA. The recoveries for 4-ene-VPA and 2,4-diene-VPA were more than 70% and that for VPA was 33-42%. R value for each compounds exceeded 0.998 in calibration curve during all the analysis. Accuracy and precision ranged from 88.3 to 113.2% and from 2.16 to 14.2%, respectively The method was successfully applied to monitor plasma concentrations of VPA, 4-ene-VPA and 2,4-diene-VPA after intravenous administration of VPA at the dose of 100 mg/kg, suggesting that these toxic metabolites may involved in the hepatotoxicity induced by VPA.

Studies on it's Practical Application to Auto Pneumatic Tyre and Manufacture of CBR (cis-1,4-polytutadiene Rubber) (Part. 3) On the Blend of Diene rubber and Turfdene rubber (CBR의 제조(製造) 및 이를 자동차(自動車) Tyre에 활용(活用)하는데 관(關)한 연구(硏究)(제3보(第三報)) Diene rubber와 Turfdene rubber와의 blend에 관(關)하여)

  • Lee, Hyun-O;Lee, Young-Kil
    • Elastomers and Composites
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    • v.7 no.1
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    • pp.21-37
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    • 1972
  • We have studied the blending effects of Diene NF 35R and Turfdene 1000R at various blending ratios 100/0, 70/30, 50/50, 30/70, 0/100, and of carbon black NAF and ISAF at various compounding ratios of 55 PHR, 65PHR, 75PHR for tyre tread rubber. As the results, it was found that; 1. For tyre tread rubber, as the blending ratio, Diene NF 35R/Turfdene 1000R, indicated 30/70, the physical properties we examined were most excellent. 2. Excellent result was obtained in case of carbon black compounding ratio of 63PHR. The compounding of ISAF made better result than that of HAF for tensile strength, tearing strength, and abrasion quantity. 3. Heat buildup obtained from compounding carbon black HAF indicated low temperature than that from compounding carbon black ISAF. As the compounding amount of carbon black increased, the heat buildup improved, and as the blending amount of Diene NF 35R decreased, the heat buildup dropped. 4. Carbon black was more efficient to Turfdene 1000R than to Diene NF 35R. 5. In this pysical properties, mooney viscosity, and mooney scorch time, as the compounding amount of carbon black increased, the values of mooney viscosity increased, but that of mooney scorch time dropped.

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Studies on it's Practical Application to Auto Pneumatic Tyre and Manufacture of CBR (Part 2.) On the Blend of Diene Rubber and SBR (CBR의 제조(製造) 및 이를 자동차(自動車) tyre에 활용(活用)하는데 관(關)한 연구(硏究) (제2보(第二報)) Diene rubber와 SBR와의 blend에 관(關)하여)

  • Lee, Hyan-O;Lee, Young-Kil
    • Elastomers and Composites
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    • v.6 no.2
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    • pp.47-63
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    • 1971
  • We have studied the blending effects of Diene 33R and styrenebutadiene rubber at various blending ratios of 100/0, 70/30, 50/50, 30/70, 0/100, and of carbon black HAF and ISAF at various compounding ratios of 55 PHR, 65 PHR, 75 PHR for tyre tread rubber. As the results, it was found that ; 1. For tyre tread rubber, when the blending ratio, Diene NF 35R/SBR 1778, indicated 30/70, the physical properties we examined were most excellent. 2. Excellent result was obtained in case of carbon black compounding ratio of 65 PHR. The compounding of ISAF made better result than that of HAF for abrasion quantity, tearing strength, and tensile strength. 3. Heat buildup obtained from compounding carbon black HAF indicated low temperature than that from compounding carbon black ISAF. As the compounding amount of carbon black increased, the heat buildup improved. And as the blending amount of Diene NF 35R decreased, the heat buildup dropped. 4. Carbon black was more efficient to SBR than to Diene Rubber. 5. It is a shortage that elongation revealed low price.

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Antioxidant and Pro-oxidant Activities of Hamcho (Salicornia herbacea L.) (함초의 항산화 및 산화 촉진 효과)

  • Kim, Ilrang
    • The Korean Journal of Food And Nutrition
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    • v.28 no.1
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    • pp.40-46
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    • 2015
  • Hamcho (Salicornia herbacea) extracts were evaluated for total polyphenol content, antioxidant and pro-oxidant activities. The total polyphenol content was 1.81 g and 0.72 g per 100 g of dried sample in water and ethanol extracts respectively. Both water and ethanol extracts of Hamcho significantly exhibited antioxidant activity. The scavenging activity of hydroxyl radical was 13.8~26.2% and 14.2~16.0% in water and ethanol extracts respectively. The inhibitory effect of conjugated diene formation was 24.6~39.1% and 28.4~39.6% in water and ethanol extracts respectively. However, pro-oxidative effect was also observed in the Hamcho extracts. The Hamcho water extract showed the pro-oxidant effect by enhancing the formation of hydroxyl radical and conjugated diene. The ethanol extract of Hamcho induced conjugated diene formation at 0.5 mg/mL but not at 1 mg/mL. The hydroxyl radical formation was not induced by the Hamcho ethanol extract. Taken together, these results show that Hamcho extracts can act as pro-oxidants by generating hydroxyl radical or conjugated diene in addition to their antioxidant properties. Therefore, this study suggests that the physiological properties of Hamcho and its use as food materials should be considered with caution because antioxidant dietary plants such as Hamcho possess possible adverse effects induced by pro-oxidant activity.

Phytochemical Study on the Rhizome of Atractylodes japonica from Korea (한국산 창출의 성분연구)

  • Yim, Dong-Sool;Yu, Seung-Cho;Chi, Hyung-Joon
    • Korean Journal of Pharmacognosy
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    • v.19 no.4
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    • pp.228-232
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    • 1988
  • From the rhizome of Atractylodes japonica Koidzumi (Compositae) which is the original plant of oriental medicine 'Cang-Zhu', four essential oil compounds were isolated. Three of them were identified as atractylon, hydroxyatractylon and $5{\alpha}H,\;10{\beta}-selina-4(14),\;7(11)-diene-8-one$, which were already known as the constitutents of Atractylodes Rhizoma. The fourth is a novel polyacetylene type compound, and the structure is postulated as 1, 4-diacetoxytetradeca-6, 12-diene-8, 10-diyne by the spectral data.

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