• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1243-1249
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• 2006

Volatile flavor compounds in commercial crab-like flavorants were compared by mean of solid phase microextraction(SPME) and liquid continuous extraction (LLCE)/GC/MSD methods. A total of 86 volatile flavor compounds were detected. Of these, 71 were positively identified consisting mainly of sulfur-containing compounds (13), aldehydes (3), ketones (2), esters (26), alcohols (5), aromatic compounds (3), terpenes (8), acids (2) and miscellaneous compounds (9). SPME method was more effective than LLCE method in detection of volatile components in commercial crab-like flavorants. Eight S-, N-containing compounds such as dimethyl sulfide, dimethyl disulfide, dipropyl disulfide, 3-(methylthio)propyl acetate, 3-(methylthio) propanal, 3-(methylthio) propanol, 2-methyl-3-(methylthio) pyrazine and 2-methyl-5-(methylthio) pyrazine, 8 esters such as styrallyl acetate, ethyl acetate, isoamyl acetate, benzyl acetate, ethyl pentanoate, butyl pentanoate, isoamyl pentanoate and furfuryl acetate were considered as major components in crab-like flavorants.

• The Korean Journal of Food And Nutrition
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• v.13 no.5
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• pp.483-489
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• 2000

Wild Chopi leaves were harvested near Chounghwa Mt. Sangju city in Kyungpook province. Chopi leaves were dried naturally and crushed with and without blanching. From mechanical analysis(GC). fifty five peaks were identified as volatile materials in no blanching leaf. Among the fifty five peaks, twenty three peaks were identified as hydrocarbones(dodecane, sabinene, myrcene etc.), ten peaks as alcohols (isobutylalcohol. cis-pentenol, 1-pentenol, 1-penten-3-ol etc.), seven peaks as aldehydes (3-methylbua-tanal, hexanal, 2,6-dimethyl hept-5-al etc.), four peaks as ketones(3-hydroxy-2-butanone, 2-nonanone, 2-undecanone, 2-tridecanone) and six peaks as esters ( cis-3-hexenyl acetate, linalyl acetate. citronellyl acetate, nervy acetate etc.). Other peaks were founded as 3-cyano-2,5-dimethylpyrazine, dimethyl sulfide, chloroform, 1,8 cineole. Thirty five peaks were identified as volatile materials in blanching leaf. Twenty peaks were identified as hydrocarbones(1,1-oxybis-ethane, $\alpha$-pinene, camphene. myrcene, $\beta$-phellan-drene, $\beta$-caryophyllene etc.), as alcohol(L-linalool, (-)-isopulgerol, $\alpha$-terpineol. citronellol etc.), as aldehydes(nonanal, citronellal), as ketones(2-undecanone, 2-tridecanone etc.) and as esteres(citronellyl acetate. cis-3-hexenyl acetate, neryl acetate etc.). Other peaks were found as 3-cyano-2,5-dimethyl-pyrazine. The amount of volatile materials such as $\alpha$-pinene, myrcene, $\beta$-phellanderene, L-linalool, citronellal, citronellyl acetate, $\beta$-caryophyllene were detected abundantly among the volatile materials.

• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.1900-1906
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• 2012

Three carbazole chromophores featuring dicyano, cyano, ethyl acetate and dimethyl acetate groups as an acceptor moiety with a ${\pi}$-conjugated spacer and $N$-methyl dibenzo[$b$]pyrole as donor were synthesized by Knovenagel condensation and characterized by IR, $^1HNMR$, $^{13}CNMR$, UV-vis, fluorescence spectroscopy, electrochemistry and theoretical B3LYP/6-$311G^*$ level whilst NLO properties and spectroscopic quantities were calculated. Calculations showed remarkable trend with HOMO located on the donor moiety and LUMO on the acceptors dicyano methylene, cyano, ethyl acetate methylene and dimethyl acetate methylene. In agreement with the calculations, solvatochromic, behavior intramolecular charge transfer band was observed in the visible region.

• Korean Journal of Medicinal Crop Science
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• v.10 no.4
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• pp.298-302
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• 2002

The essential oils were isolated by hydrodistillation and their composition determined capillary GC method with standards. The essential oil content showed significant differences between the two populations on the vegetative organs. The essential oil level of the leaves and roots was considerably higher in the Korean population at full flowering and waxy ripening stage but essential oil content of the roots was significantly higher in the Hungarian taxon at leaf rosette stage. We observed the essential oil accumulation tendency was mianly dependent on plant organs and intra-specific taxon during the vegeation period. Butylidene-phthalide was proved to be the main component of the oil in both population roots (50.9-73.3%), while dimethyl-acetate was showed as a major compound on the over-ground parts (56.7-62.0%). The qualitative composition of the essential oil in the reproductive organs concerning the identified compounds was the same as the vegetative parts with the main component ${\alpha}-phellandrene$ (4.8-28.1%) and butylidene-phtalide (9.7-16.1%), The quantitative composition showed some changes during the ontogenesis phases. Most characteristic ones are the decreasing proportion of dimethyl-acetate (from 7.3% to 1.1%) and the appearance of ${\alpha}-pinene$ (from 0.5% to 1.5%) only after fruit setting in both population.

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.549-554
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• 1990

Glycosidically bound fraction was separated from apricot by Amberlite XAD-2 adsorption and eluted with methanol. Aglycones were liberated from the bound fraction by enzymatic hydrolysis, acid hydrolysis or by means of simultaneous distillation-extraction at pH 3.0. A total of 40 components were identified in three bound volatile fractions. Besides linalool oxide, linalool. ${\alpha}-terpineol$, nerol, geraniol, benzyl alcohol and 2-phenylethyl alcohol, previously reported as glycosidically bound volatiles, the following components were identified for the first time as glycosidically bound volatiles in apricot: 2,6-dimethyl-3,7-octadiene-2,6-diol , 3.7-dimethyl-1,5-octadiene-3,7-diol, (E)- and (Z)-2.6-dimethyl-2,7-octadiene-1,6-diol, $3,4-didehydro-{\beta}-ionol,\;3-oxo-{\alpha}-ionol$, $3-hydroxy-7,8-dihydro-{\beta}-ionol,\;3-oxo-7,8-dihydro-{\alpha}-ionol ,\;3-hydroxy-{\beta}-ionone$, eugenol, 4-hydroxyethylphenyl acetate and 2,3-dihydrobenzofuran.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.149.2-149
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• 2003

비조사 김치와 2.5, 5 및 10 kGy로 방사선 조사된 김치로부터 SDE 방법으로 추출한 휘발성 유기화합물을 분석하여 변화를 확인하였다. 김치의 주요 휘발성 유기화합물로 ethyl formate, ethyl acetate, ethanol, dimethyl disulfide, methyl 2-propenyl disulfide가 다량 함유되어 있었고, ethyl methyl disulfide, 4-cyano-1-butene, pentane dinitrile 등도 상당량 함유되어 있었다. Ethyl formate, ethyl acetate, ethanol은 조사선량이 증가함에 따라 상당량 증가하는 것으로 확인되었으며, dimethyl disulfide, ethyl methyl disulfide, methyl propyl disulfide, pentane dinitrile, S-methyl methyl thiosulfonate 등도 선량이 증가함에 따라 함량이 증가하였다. 1-Penten-3-ol은 조사선량에 따라 감소하였다.

• Natural Product Sciences
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• v.3 no.2
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• pp.104-105
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• 1997

In the course of continous work on tubers of Gastrodia elata, a new constituent was isolated from the ethyl acetate soluble fraction prepared from the methanol extract. The structure of the compound was identified as ${\alpha},{\alpha}'-[bis-2-(5-carboxaldehydo)furanyl]-dimethyl$ ether from the elemental analytical and spectroscopic data. This compound was once isolated from Cirsium chlorolepis and named as cirsiumaldehyde. This is the first furan type compound isolated from Gastrodia elata.

• Archives of Pharmacal Research
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• v.15 no.1
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• pp.87-90
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• 1992

The syntheses of novel heterocyclic base modified pyrimidine nucleosides are described. 5, 6-dimethyl-4-hydroxy-3-methoxy-1-$(\beta$-D-ribofuranosyl)2(1H)-pyridinone 7 was synthesized by condensation of silylated 5, 6-dimethyl4-hydroxy-3-methoxy-2(1H)-pyridione 7 was synthesized by condensation of silylated 5, 6-dimethyl-4-hydroxy-3-methoxy-2(1H)-pyridinone with $\beta$-D-ribofuranose-1-acetate-2, 3, 5-tribenzoate in dichloroethane in the presence of Lewis acid followed by debenzoylation. The 2, 2'-anhydro-5, 6-dimethyl-2-hydroxy-3-methoxy-1-$\beta$-D-arabinofuranosyl-4-pyridinone 8 was obtained from the reaction of the free ribonucleoside 7 and diphenyl carbonate in DMF. None of these compounds showed any significant antiviral ad antitumor activities in vitro tests.

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.144-150
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• 2013

The kinetics of the transesterification of dimethyl terephthalate (DMT) with ethylene glycol (EG) was studied in a batch reactor. Bishydroxyethyl terephthalate (BHET), which is poly(ethylene terephthalate) (PET) monomer, can be produced by the transesterification reaction. Zinc acetate was used as a catalyst. Previous kinetic studies was carried out in a semi-batch reactor where generated methanol was removed so that reverse reactions were not considered in the kinetic expressions, resulting in inaccuracy of the kinetic model. Mathematical models of a batch reactor for the tranesterification reaction were developed and used to characterize the reaction kinetics and the composition distribution of the reaction products. More accurate models than previous ones were obtained and found to have a good agreement between model predictions and experimental data. Effect of process variables on the esterification reaction was investigated based on the experimental and simulation results.

• Journal of the Korean Chemical Society
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• v.30 no.6
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• pp.548-552
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• 1986

A stereoselective synthesis of 3-phenoxybenzyl (${\pm}$)-cis and trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-1-cyclopropanecarboxylic acid starting from readily available 2-methyl-3-buten-2-ol($\underline{2}$) is described. Allylic rearrangement of 2-methyl-3-buten-2-ol, in the presence of acetic acid and acetic anhydride gave 3-methyl-2-butenyl acetate($\underline{3}$). The [3,3] sigmatropic rearrangement of the allyl acetate($\underline{3}$), as the silylketene acetal, produced the ${\gamma},\;{\delta}$-unsaturated acid($\underline{4}$). Treatment of 3,3-dimethyl-4-pentenoic acid($\underline{4}$) with SOCl2 followed by esterification with 3-phenoxybenzyl alcohol yielded 3, 3-dimethyl-4-pentenoic acid ester($\underline{5}$). Addition of carbon tetrachloride to the olefin ester($\underline{6}$) furnished 4,6,6,6-tetrachloro-3,3-dimethylhexanoic acid ester ($\underline{7}$). Cyclization with potassium t-butoxide and elimination of hydrogen chloride afforded 3-phenoxybenzyl (${\pm}$) cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-1-cyclopropanecarboxylic acid.