• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.2
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• pp.136-146
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• 1987

Flavor components were trapped by stimultaneous steam distillation-extraction method for investigating it in the bellflower roots and fractionated into four groups such as a neutral, a basic, a phenolic and an acidic fraction. An acidic fraction methylated with diazomethane solution and three others were analysed by GC and GC-MS equipping a fused silica capillary column, and S-containing compounds in these were detected with a flame photometric detector (FPD). The total of one hundred and three compounds from the bellflower roots were identified: they were 6 aliphatic hydrocarbons, 10 aromatic hydrocarbons, 2 terpene hydrocarbons, 12 alcohols, 8 terpene alcohols, 17 aldehydes, 3 terpene aldehydes, 5 ketones, 5 esters, 3 furans, 2 thiazoles, 2 lactones, 2 sulfides, 9 phenols, l2 carboxylic acids and 5 others. The greater part of the others except carboxylic acids were identified from a neutral fraction of which was assumed to be indispensable for the reproduction of bellflower root odor in a sensory evaluation. As a result of a sensory evaluation, 1-hexanal, trans-2-hexenal, 1-hexanol, cis-3-hexenol, trans-2-hexenol, 1-octen-3-ol and so forth identified in a neutral fraction were considered to be the key compounds of grass-like odor in the bellflower roots.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.366-371
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• 2007

The volatile components in Eoyuk-jang, a traditional Korean fermented food, were isolated using solvent extraction, and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 36 components, including 11 aliphatic hydrocarbons, 4 acids, 2 ketones, 5 phenols, 7 alcohols, 1 pyrazines, 4 pyrones and furanones, and 2 miscellaneous components, were found in Eoyuk-jang; among them, butanoic acid was quantitatively dominant. In addition, the aroma-active compounds were determined by gas chromatography-olfactometry (GC-O) using aroma extract dilution analysis (AEDA). A total of 20 aroma-active compounds were detected by GC-O. Butanoic acid (rancid) and methional (cooked potato-like) were the most potent aroma-active compounds with the highest FD factors $(Log_3$, FD), followed by 2-methyl-2-butanol (soysauce-like), 3-hydroxy-2-butanone (buttery), and 2-furanmethanol (burnt sugar-like).

• Korean Journal of Food Science and Technology
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• v.40 no.5
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• pp.497-502
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• 2008

The volatile components in Gamdongchotmoo kimchi, unfermented and fermented for 3 or 25 days, were extracted via solvent-assisted flavor evaporation (SAFE), and then analyzed via gas chromatography/mass spectrometry (GCMS). A total of 57 components, including 14 S-containing compounds, 22 terpene hydrocarbons, 13 aliphatic hydrocarbons, 4 alcohols, and 4 miscellaneous components, were detected in Gamdongchotmoo kimchi. Among them, the S-compounds were quantitatively dominant. The aroma-active compounds were also determined via gas chromatography-olfactometry (GC-O), using aroma extract dilution analysis (AEDA). A total of 16 aroma-active compounds were detected via GC-O. The most intense aroma-active compounds in Gamdongchotmoo kimchi included 4-isothiocyanato-1-butene ($Log_3$ FD factor 7, rancid), an unknown($Log_3$ FD factor 7, spicy) and another unknown ($Log_3$ FD factor 7, seasoning-like). In addition, other aroma-active compounds, including dimethyldisulfide ($Log_3$ FD factor 6, rotten onion-like/sulfury), 2-vinyl-[4H]-1,3-dithiin ($Log_3$ FD factor 5, spicy/garlic-like), and an unknown ($Log_3$ FD factor 5, rancid/cheese-like) might be crucial to the flavor characteristics of Gamdongchotmoo kimchi.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.98-101
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• 1991

To investigate the aroma difference of commercial Korean green tea caused by manufacturing process and harvesting time, analysis of aroma concentrates of steamed green teas(1st tea, 2nd tea) and parched green teas(1st tea, 2nd tea) was accomplished. Steamed green tea, which had a briskness, greenish odor and sweet-floral odor, contained large amounts of terpene alcohols such as linalool, nerolidol, ketones such as cis-jasmone, 2,6,6-trimethyl-2-hydroxycyclohexanone and indole, Parched green tea, which had a slightly greenish odor and floral, roast odor, contained large amounts of terpene alcohols such as linalool, geraniol, aromatic alcohols such as benzylalcohol, phenylethanol and phenol, indole. Almost same tendency of odor component change of 1st tea and 2nd tea differed to harvesting time being observed in steamed tea and parched tea. In 2nd tea of both samples, aliphatic alcohols such as 1-penten-3-ol, cis-2-penten-1-al and two 2, 4-heptadienal(cis, trans and trans, trans) increased remarkably. It seems that these four components effects on the grade of the odor.

• Journal of the Korean Chemical Society
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• v.21 no.2
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• pp.108-120
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• 1977

The approximate rates and stoichiometries of the reaction of lithium borohydride, with fifty two selected organic compounds containing representative functional groups under the standard condition (tetrahydrofuran, $0^{\circ}$), were studied.Among the active hydrogen compounds,primary alcohols and compounds containing an acidic proton liberated hydrogen relatively fast, but secondary and tertiary alcohols very sluggishly. All the carbonyl compounds examined were reduced rapidly within one hour. Especially, among the ${\alpha}{\beta}$-unsaturated carbonyl compounds tested, the aldehydes consumed one hydride cleanly, however the cyclic ketones consumed more than one hydride even at $-20^{\circ}$. Carboxylic acids were reduced very slowly, showing about 60% reduction in 6 days at $25^{\circ}$, however acyl chlorides reduced immediately within 30 minutes. On the other hand, the reductions of cyclic anhydrides proceeded moderately to the hydroxy acid stage, however the further reductions were very slow. Aromatic and aliphatic esters, with exception of the relatively moderate reduction of acetate, were reduced very slowly, however lactones were reduced at a moderate rate. Epoxides reacted slowly, but amides and nitriles as well as the nitro compounds were all inert to this reagent. And cyclohexanone oxime and phenyl isocyanate were reduced very sluggishly. Last of all, all sulfur compounds studied were inert to this hydride.

• Analytical Science and Technology
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• v.17 no.1
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• pp.37-44
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• 2004

An alcohol oxidase from Hansenula polymorpha was strongly induced when cells were grown with 0.5% methanol supplementation as the carbon source. The induced Hansenula polymorpha alcohol oxidase was purified to electrophoretic homogeneity by using DEAE-Sephacel and Mono Q column chromatographys. The enzyme oxidized mainly primary aliphatic alcohols and exhibited high substrate specificity towards ethanol and methanol. The activity of the enzyme optimally proceeded at pH 8.5 and $50^{\circ}C$. The midpoint of the temperature-stability curve for the enzyme was approximately $52^{\circ}C$ and the enzyme was not completely inactivated even at $65^{\circ}C$ temperature. The enzyme showed resistance toward detergents and highly stable over 7 weeks of storage condition. This Hansenula polymorpha alcohol oxidase may be useful for the enzymatic determination of alcohol and for the industrial production of alcohols and aldehydes.

• Bulletin of the Korean Chemical Society
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• v.13 no.5
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• pp.531-537
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• 1992

The approximate rates and stoichiometry of the reaction of excess potassium 2-thexyl-1,3,2-dioxaborinane hydride(KTDBNH) with 55 selected compounds containing representative functional groups under standardized conditions (tetrahydrofuran, TEX>$0^{\circ}C$, reagent : compound=4 : 1) was examined in order to define the characteristics of the reagent for selective reductions. Benzyl alcohol and phenol evolve hydrogen immediately. However, primary, secondary and tertiary alcohols evolve hydrogen slowly, and the rate of hydrogen evolution is in order of $1^{\circ}$> $2^{\circ}$> $3^{\circ}$. n-Hexylamine is inert toward the reagent, whereas the thiols examined evolve hydrogen rapidly. Aldehydes and ketones are reduced rapidly and quantitatively to give the corresponding alcohols. Cinnamaldehyde is rapidly reduced to cinnamyl alcohol, and further reduction is slow under these conditions. The reaction with p-benzoquinone dose not show a clean reduction, but anthraquinone is cleanly reduced to 9,10-dihydro-9,10-anthracenediol. Carboxylic acids liberate hydrogen immediately, further reduction is very slow. Cyclic anhydrides slowly consume 2 equiv of hydride, corresponding to reduction to the caboxylic acid and alcohol stages. Acid chlorides, esters, and lactones are rapidly and quantitatively reduced to the corresponding carbinols. Epoxides consume 1 equiv hydride slowly. Primary amides evolve 1 equiv of hydrogen readily, but further reduction is slow. Tertiary amides are also reduced slowly. Both aliphatic and aromatic nitriles consume 1 equiv of hydride rapidly, but further hydride uptake is slow. Analysis of the reaction mixture with 2,4-dinitrophenylhydrazine yields 64% of caproaldehyde and 87% of benzaldehyde, respectively. 1-Nitropropane utilizes 2 equiv of hydride, one for hydrogen evolution and the other for reduction. Other nitrogen compounds examined are also reduced slowly. Cyclohexanone oxime undergoes slow reduction to N-cyclohexylhydroxyamine. Pyridine ring is slowly attacked. Disulfides examined are reduced readily to the correponding thiols with rapid evolution of 1 equiv hydrogen. Dimethyl sulfoxide is reduced slowly to dimethyl sulfide, whereas the reduction of diphenyl sulfone is very slow. Sulfonic acids only liberate hydrogen quantitatively without any reduction. Finally, cyclohexyl tosylate is inert to this reagent. Consequently, potassium 2-thexyl-1,3,2-dioxaborinane hydride, a monoalkyldialkoxyborohydride, shows a unique reducing characteristics. The reducing power of this reagent exists somewhere between trialkylborohydrides and trialkoxyborohydride. Therefore, the reagent should find a useful application in organic synthesis, especially in the field of selective reduction.

• Archives of Pharmacal Research
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• v.7 no.1
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• pp.1-9
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• 1984

Polyethylene glycol 20, 000 and 6, 000 were found to have an upper consolute temperature, called "cloud point", and the effects of various additives on the polythylene glycols were investigated in this study. Electrolytes lowered the cloud point in proportion to their concentrations through dehydration and electrostriction. It was found that anions played a more important role than cations and the effects of both the cations and the anions clearly followed the classical Hofmeister series. However, the Schultze Hardy rule holds for the effect of anions, and fails for the effect of cations. Salts of large polarizable anions such as iodide and thiocynate rather raised the cloud point, and their effects were ascribed to the fact that they break the water structure and weaken hydrophobic bonding of the polyxyethylene moiety. Nitrates of polyvalent cations also raised the cloud point. This was ascribed to the complex formation between the polyvalent cations and ether oxygens of the polyoxyethylenes. This explained the failure 'of the Schultz-Hardy rule for cations. Uncharged aromatic compounds drastically lowered the clound point, while aliphatic alcohols slightly lowered the cloud point, This result suggests that there might be some interaction between ether oxygens and aromatic nucleus.c nucleus.

• Bulletin of the Korean Chemical Society
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• v.25 no.4
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• pp.501-505
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• 2004

Esterification of aliphatic or aromatic carboxylic acids with alcohols using 2-(4-nitrobenzenesulfonyl)-4,5-dichloropyridazin-3(2H)-one (3) in the presence of base in organic solvents gave the corresponding esters in excellent yields

• KEPCO Journal on Electric Power and Energy
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• v.2 no.3
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• pp.447-452
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• 2016

It is imperative to develop an effective pathway to depolymerize lignin into liquid fuel that can be used as a bioheavy oil. Lignin can be converted into liquid products either by a solvent-free thermal cracking in the absence air, or thermo-chemical degradation in the presence of suitable solvents and chemicals. Here we show that the solvent-assisted liquefaction has produced promising results in the presence of metal-based catalysts. The supercritical ethanol is an efficient liquefaction solvent, which not only provides better solubility to lignin, but also scavenges the intermediate species. The concentrated sulfuric acid hydrolysis lignin (CSAHL) was completely liquefied in the presence of solid catalysts (Ni, Pd and Ru) with no char formation. The effective deoxy-liquefaction nature associated with scEtOH with aid hydrodeoxygenation catalysts, resulted in significant reduction in oxygen-to-carbon (O/C) molar ratio up to 61%. The decrease in oxygen content and increase in carbon and hydrogen contents increased the calorific value bio-oil, with higher heating value (HHV) of $34.6MJ{\cdot}Kg^{-1}$. The overall process is energetically efficient with 129.8% energy recovery (ER) and 70.8% energy efficiency (EE). The GC-TOF/MS analysis of bio-oil shows that the bio-oil mainly consists of monomeric species such as phenols, esters, furans, alcohols, and traces of aliphatic hydrocarbons. The bio-oil produced has better flow properties, low molecular weight, and high aromaticity.