• 제목/요약/키워드: methyl acetate

검색결과 371건 처리시간 0.031초

한국산 산초열매와 나무의 휘발성 향기성분 (Volatile Flavor Components of Korean Sancho Fruit and Tree(Zanthoxylum schinfolium))

  • 이종원
    • 한국식품영양학회지
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    • 제11권5호
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    • pp.493-498
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    • 1998
  • An attempt was in this to analyzer volatile flavor components of sancho(Zanthoxylum schinfolium). Essential oils in sancho tree and fruit isolated by a simulataneous steam distillation (SDE) methods using n-pentane/diethyl ether as solvent. A total of 57 and 44 components were identified by gas chromatography(GC) and combined gas chromatography spectrometry (GC-MS), respectively. Granyl acetate(29.23%) geraniol (6.80%, p-isopropyl-2-chclohexenone(5.53%), phellandral (4.10%) in sancho fruit and 4, 6, 6-trimethyl-bicyclo(7.47%), T-carvelo(4.60%, ${\alpha}$-cypernone(3.58%) in sancho tree were found to be major volatile flavor. 22 compnents including myrcene, limonene, 1, 8-cinol in sancho fruit and 10 components including 4-(1-methylethyl)-cyclohexanol, methyl undecyl ketone in sancho tree were identified. The contents of unsaturated fatty acids of palmitic acid(24.34%), myristic acid(3,68%) in sancho tree was higher than that of the sancho fruit.

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Model-on-demand Predictive Control of Polymerization Reactor Systems

  • Hur, Su-Mi;Park, Myung-June;Rhee, Hyun-Ku
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.97.2-97
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    • 2001
  • This work is concerned with the improvement of the productivity and the product quality in the polymerization reactors by using model-on-demand predictive control(MoDPC). This technique is applied to a continuous styrene polymerization reactor and a semibatch methyl methacrylate (MMA)/vinyl acetate(VAc) copolymerization reactor. The regress is constructed with the most influential variables the conversion and the jacket inlet temperature for the styrene polymerization reactor, and the free volume and the reactor temperature for the MMA/VAc copolymerization reactor through open loop operations. From the simulation results for setpoint tracking and disturbance rejection problems, it is demonstrated that the MoDPC shows ...

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한국산 재배대황엽의 약효성분 -엽의 안트라퀴논- (Pharmaco-Constituents of Korean Cultivated Rhubarb Leaves -The Anthraquinones from Leaves-)

  • 함인혜;김일혁
    • 약학회지
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    • 제38권4호
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    • pp.410-417
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    • 1994
  • As one of the studies for Korean cultivated Rhubarb, which has been used stomachic bitter, laxative and purgative, etc, MeOH extract of the leaves was fractionated with ether, ethylacetate. From the ether fraction of MeOH extract, two anthraquinone derivatives, 1,6,8-trihydroxy-3-methyl anthraquinone(emodin, $C_{15}H_{10}O_5$), 1,6,8-trihydroxy-3-hydroxymethyl anthraquinone (citrerosein, $C_{15}H_{10}O_6$) and from the ethyl acetate fraction of MeOH extract, one anthraquinone derivative, emodin-8-${\beta}$-D-glucopyranoside$(C_{21}H_{20}O_{10})$ were isolated and identified through the physico-chemical properties and spectroscopic evidences(UV, IR, NMR, Mass), respectively.

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사방오리 잎의 Triterpenoid 및 Flavonoid 화합물 (Triterpenoids and Flavonoids Isolated from the Leaves of Alnus firma)

  • 유영법;;;;박종철
    • 생약학회지
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    • 제38권1호
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    • pp.76-83
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    • 2007
  • In this study, three triterpenoids, two steroids and nine flavonoids were isolated from the leaves of Alnus firma Sieb. et Zucc. On the basis of spectroscopic evidences, the structures of these compounds were established as ${\beta}$-amyrin acetate, ${\beta}$-amyrin, ${\beta}$-sitosterol, alnustic acid methyl ester, ${\beta}$-sitosterol glucoside, pinocembrin, alnustinol, quercetin, quercetin-3-O-${\alpha}$-L-arabinofuranoside, quercetin-3-O-${\alpha}$-L -rhamnopyranoside, quercetin-3-O-${\beta}$-D-glucopyranoside, myricetin-3-O-${\beta}$-D-galac-topyranoside, (+)-catechin and (-)-epicatechin.

Riboflavin 이 지질대사에 미치는 영향 (Effect of Riboflavin on Lipid Metabolism)

  • 박란숙
    • Journal of Nutrition and Health
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    • 제19권3호
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    • pp.169-176
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    • 1986
  • The effect of riboflavin feeding on lipid emtabolism in rat were studied. 70 male Sprague-Dawley rats were divided into 7 diet group ; control, riboflavin, cholesterol, MLHP (methyl linoleate hydroperoxide) cholesterol plus MLHP, cholesterol plus riboflavin, cholesterol plus MLHP plus riboflavin. After 4 weeks formular feeding sera of animals were collected, then checked cholesterol, triglyceride, phospholipid levels and lipoprotein by use of cellulose acetate papter. The results were as follows ; 1) Marked increase of triglyceride and phospholipid levels were found in the group feeding with cholesterol, cholesterol plus MLHP. 2) Combined riboflavin feeding prevented the increase of triglyceride and phospholipid levels in the group of cholesterol, cholesterol plus MLPH. 3) Also combined riboflavin feeding prevented the increase of $\beta$-lipoprotein fraction in cholesterol feeding group. Our results demonstrate that riboflavin has an inhibitory effects on the derangements of lipid metabolism due to administration of cholesterol, cholesterol plus MLHP.

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Pytochemical Constituents of the Aerial Parts from Solidago virga-aurea var. gigantea

  • Choi, Sang-Zin;Choi, Sang-Un;Lee, Kang-Ro
    • Archives of Pharmacal Research
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    • 제27권2호
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    • pp.164-168
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    • 2004
  • The chromatographic separation of the MeOH extract of the aerial parts of Solidago virga-aurea var. gigantea $M_{IQ}$ . (Compositae) led to the isolation of six terpenoids and four phenolic compounds, trans-phytol (1), ent-germacra-4(15),5,10(14 )-trien-1$\alpha$-ol (2), $\beta$-amyrin acetate (3), ent-germacra-4(15),5,10(14)-trien-1$\beta$-ol (4), $\beta$-dictyopterol (5), oleanolic acid (6), kaempferol (7), kaempferol-3-O-rutinoside (8), methyl 3,5-di-O-caffeoyl quinate (9), and 3,5-di-O-caffeoyl quinic acid (10). Their structures were established by chemical and spectroscopic methods. Compounds 4, 5, and 10 showed moderate cytotoxicity against five cultured human tumor cell lines in vitro with its E $D_{50}$ values ranging from 1.52∼18.57 $\mu\textrm{g}$/mL.L.

수입 과일중 2,4-D의 잔류분석법 및 잔류량 연구 (Studies on the Analytical Methods and Quantity of Residual 2,4-D in Imported Fruits)

  • 홍무기
    • 한국식품위생안전성학회지
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    • 제9권2호
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    • pp.89-94
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    • 1994
  • A simple, safe, and sensitive gas chromatographic method using packed column and electron capture detector to analyze 2, 4-D herbicide in imported lemon, grapefruit, and orange was described and its usefulness evaluated. In this scheme of analysis the acid herbicide was converted into its alkyl esters by an one-step reaction prior to analysis. The herbicide in the fruits was extracted with ethyl acetate and partitioned against dichloromethane for purification, and the extracts finished partitioning were derivatized with alcohol, using sulfuric acid as a catalyst to form the corresponding alkyl derivatives. The analytical scheme studiedwas found to be applicable for the herbicide in the fruits without a column clean-up procedure. The mean recoveries of the herbicide for lemon samples fortified at 0.1 mg/kg and 1.0 mg/kg were 93% and 95%, respectively. The detection limit was 0.5 $\mu\textrm{g}$/kg for 2.4-D methyl ester.

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VDCN계 공중합체의 비선형 유전 특성 (Nonlinear Dielectric Properties of VDCN Copolymers)

  • 강대하;박상호
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제51권7호
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    • pp.279-286
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    • 2002
  • Linear and nonlinear complex permittivities were measured for copolymers of vinylidene cyanide(VDCN) with vinyl acetate(VAc), vinyl propionate(VPr), vinyl bezoate(VBz), styrene(St) and methyl methacrylate(MMA). Experimental results are well fitted by the function (equation omitted) except at low frequency where dc conduction dominates. The analysis of dielectric relaxation mechanism by combined knowledge about linear and nonlinear dielectric permittivities and dipoles give us informations about electrical and thermal motions in these copolymers. According to the analysis it could be found that the variation for temperature of the dielectric relaxation strength in these copolymers is related to the interaction between dipoles and the nonlinear dielectric effect factor R$_{s}$ is proportional to square of the dipolar correlation factor R$_{p}$././.

유기 Hectorite Gel의 Rheology에 미치는 극성연가제에 관한 연구

  • 김창규
    • 대한화장품학회지
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    • 제10권1호
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    • pp.49-74
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    • 1984
  • Rheology of gels prepared with stearyl dimethyl benzyl ammonium hectorite (SDBAH) and various polar additives in n-butyl acetate was investigated by measuring the viscosity and rheogram. Including generally recognized polar additives, additional studies on the rheogram and viscosity were made with ether-type methyl cellosolve and carbitol, with dimethyl sulfoxide (DMSO) having sulfonyl group, and furthermore with above-mentioned polar additives containing small quantity of water, It was observed that molecular size, dipole moments and dielectric constants of polar additives had a great influence on viscosity increase and rheology of SDBAH gel, and the increase of SDBAH interlayer spacing was important factor in gel formation and viscosity change. It was also shown that thixotropy effect was increased with the increase of polar additive concentration, finally changed to rheopexy from thixotropy as the concentration of polar additives was increased more than about 40% of SDBAH weight. In addition thixotropy changed to rheopexy as the increase of shear rate. It was further found that the aqueous solutions of polar additives (water content, 5-25%) had more effects on rheology than additives without water, and particularly 95clo DMSO solution was the most effective. And the optimum concentration of polar additives showing maximum viscosity in the same SDBAH concentration system was examined.

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Rapid Gas Chromatographic Profiling and Screening of Acidic Non-Steroidal Antiinflammatory Drugs in Biological Samples

  • Kim, Kyoung-Rae;Shin, You-Jin;Shim, Won-Hee;Myung, Seoung-Won
    • Archives of Pharmacal Research
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    • 제17권3호
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    • pp.175-181
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    • 1994
  • The solid-phase extraction (SPF) with subsequent tert-butyldimethylsilyl (TBDMS) derivatization was investigated for the rapid profiling and screening of various carboxylated non-steroidal antiinflammatory drugs (NSAIDs) simultaneously in biological fluid samples. Compared to the conventional SPF in adsorption mode using Chromosorb 102, Chromosorb 107, Carbopak B and Thermosorb, the SPF in partition mode using Chromosorb P as the adsorbent, and ethyl acetate/methylene chloride as the eluting solvents provided hightest overall recovenies of the NSAIDs from aqueous solutions with good precision. The solid-phase extracted NASIDs were silylated with N-methyl-N-(tert-butyldimethylsily)trifuoroacetamide to TBDMS derivatives and directly analyzed by capillary gas chromatography and gs chromatography-mass spectrometry. The usefulness of the present method was examined for the profilling and screening of saliva, serum and urine samples for various NSAIDs simultaneously.

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