• Title/Summary/Keyword: methyl ester

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Fatty Acid and Sterol Composition of Leaf Protein Coagulated at Different pH (여러 pH에서 가열응고(加熱凝固)시켜 조제(調製)한 녹엽단백질(綠葉蛋白質)의 지방산(脂肪酸)과 Sterol조성(組成))

  • Kim, Jong Kyu
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.12 no.3
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    • pp.259-263
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    • 1983
  • This experiment was carried out to investigate the effect of pH at coagulation on fatty acid and sterol composition of green LPC. Green juice of Italian ryegrass, red clover, oats and alfalfa was adjusted at pH 4, 6, 8 and heated at $85^{\circ}C$ for ten minutes. Green LPC was taken from the above green juice. The results obtained were as follows. 1. Green LPC of Italian ryegrass, oats and alfalfa contained much on the order of linoleic acid, palmitic acid and linolenic acid. Methyl ester of these three fatty acid accounted for 70.4% to 86.2% of total fatty acid methyl ester. Green LPC of red clover contained much palmitic acid, linoleic acid, and linolenic acid. These three fatty acid methyl ester accounted for 82.5% to 86.2% of total fatty acid methyl ester. 2. Linolenic acid was highest in the green LPC of red clover, oats and alfalfa which was adjusted at pH 8 and heated and coagulated, and next at pH 6, and pH 4, respectively. Linolenic acid was highest in the green LPC of Italian ryegrass which was adjusted at pH 6, next pH 8, and pH 4. 3. Green LPC of red clover and alfalfa contained cholesterol. The all green LPC contained campesterol, stigmasterol and sitosterol. 4. Sterol was highest in the green LPC of Italian ryegrass, red clover and oats which was adjusted at pH 8 and next at pH 4, and pH 6, respectively. Sterol was highest in the green LPC of alfalfa which was adjusted at pH 8, and next at pH 6, and pH 4, respectively.

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Gas-Liquid Chromatographic Determination of Haloxyfop-R and lts Methyl Ester Residues in Soils and Soybeans (토양과 대두중 Haloxyfop-R 및 Haloxyfop-R-methyl의 기체크로마토그래피를 이용한 잔류분석)

  • Lee, Young-Deuk
    • Korean Journal of Environmental Agriculture
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    • v.16 no.4
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    • pp.333-340
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    • 1997
  • An analytical method was developed to determine residues of haloxyfop-R and its methyl ester in soils and soybeans using gas-liquid chromatography (GLC) with electron capture detector (ECD). Soil or soybean sample was acidified and extracted with acetone. The extract was then subjected to ion-associated partition to individually separate haloxyfop-R and the neutral methyl ester. One phase containing haloxyfop-R was methylated with $BF_3$/methanol, partitioned to n-hexane and analyzed by GLC/ECD. The other phase containing the methyl ester was further purified by Florisil column chromatography prior to GLC determination. No cross contamination was found between two phases containing each of the acid and methyl ester, thus two compounds can be separately determined as the identical haloxyfop-R-methyl. Overall recoveries of haloxyfop-R from fortified samples averaged 88.2${\pm}$3.9% (n=12) and 88.3${\pm}$4.0% (n=6) for soils and soybeans respectively, and those of haloxyfop-R-methyl showed mean values of 89.2${\pm}$4.0% (n=12) and 85.6${\pm}$5.6% (n=6). Detection limits of both haloxyfop-R and its methyl esterwere 0.005㎎/㎏ and 0.01㎎/㎏ for soil and soybean samples respectively.

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cis-trans Isomeric and Substituent Effects on the Lanthanide Induced Shifts in 2-Phenylcyclopropanic System

  • So, Jung-Ho;Cho, Nam-Sook
    • Bulletin of the Korean Chemical Society
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    • v.5 no.6
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    • pp.226-230
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    • 1984
  • LIS's of cis and trans-methyl-2-phenylcyclopropanecarboxylate, cis and trans-t-butyl-2-phenylcyclopropanecarboxylate, cis and trans-N,N-dimethylcyclopropanecarboxamide, trans-2-phenylcyclopropyl methyl ketone and trans-2-phenylcyclopropyl t-butyl ketone have been studied. The LIS's hold the McConnell-Robertson relation and are mainly influenced by the steric effect. LIS's of trans isomers are larger than those of cis isomers. In trans isomers, the LIS's decrease in the following order: methyl ketone > methyl ester > N,N-dimethyl amide > t-butyl ketone${\sim}$t-butyl ester.

Synthesis and Characterization of Soybean-based Ester Insulation Oils (대두유 에스테르계 절연유의 합성과 분석)

  • Han Dong-Hee;Cho Han-Goo;Han Se-Won;Oh Dae-Hee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.1
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    • pp.40-45
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    • 2006
  • Electrical insulation is one of the most important parts in a high voltage apparatus. Traditionally mineral oils and synthetic esters have been widely used as dielectric coolants for power transformers. Recently, researchers are interested in the environmentally friendly vegetable oil from the environmental viewpoint. This paper reports on the synthesis and characterization of soybean based ester oils. Two different types of soybean based transformer oils, named as methyl ester and isopropyl ester were synthesized. The synthesis of these esters was achieved by transesterification reactions between soybean oil and alcohol in the presence of catalyst. The GC and NMR spectroscopic analysis of the esters have been performed. It was observed that isopropyl ester has better thermal resistance than methyl ester by TGA. Also, two esters have a good breakdown voltage and electrical resistance.

Glycoside Fatty Acid Polyester Synthesis by Emulsion Process (유화공정에 의한 글리코시드 지방산 폴리에스테르의 합성)

  • Kim, Hae-Sung
    • Journal of the Korean Applied Science and Technology
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    • v.19 no.2
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    • pp.137-144
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    • 2002
  • Methyl glycoside oleic acid polyester was successfully prepared from methyl glycosides and methyl oleate by emulsion interesterification in the presence of methyl fructoside oleic acid polyester as an emulsifier. Emulsion interesterification process was optimized to obtain 98% yield of methyl glycoside polyester within $3{\sim}5hr$ at temperatures as relatively low as $90{\sim}150^{\circ}C$ and $20{\sim}200mmHg$ pressure with a five-fold molar ratio of oleic acid methyl ester to methyl glycoside in the presence of 2(w/w)% potassium carbonate and 2O(v/v)% methyl fructoside polyester based on oleic acid methyl ester.

Enantioselective Hydrolysis of (R,S)-Naproxen Methyl Ester Using Two-step Acetone-treated Candida rugosa Lipase (2단계 아세톤 침전법으로부터 얻어진 Candida rugosa Lipase를 이용한 (R,S)-Naproxen Ester의 광학선택성 수화반응)

  • 이은교;최순자;정봉현
    • Microbiology and Biotechnology Letters
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    • v.28 no.4
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    • pp.223-227
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    • 2000
  • A novel two-step acetone treatment method was developed to enhance the enantioselectivity of Candida rugosa lipase (CRL) toward the hydrolysis of racemic naproxen methyl ester. The acetone-teated CRL was considerably more enantioselective than the crude CRL, yielding an enantiomeric excess of 98~100%. The crude and acetone-treated CRLs were subjected to anion exchange chromatography, and their chromatography profiles were compared. In consequence, both chromatography profiles were found to be almost identical, resulting in two separate lipase peaks (lipase A and B). The lipase B, which is known to be less enantioselective, was treated with acetone using a two-step treatment method. The enantioselectivity of acetone-treated lipase B was dramatically increased, yielding an enantiomeric excess of 99%.

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The Chemical Constituents of Bezoar Bovis (우황 (Bezoar Bovis)의 성분연구)

  • In Kyu Kim;Sun Ku Park;Hyun Cheol Oh;Kyu Wan Kim
    • Journal of the Korean Chemical Society
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    • v.35 no.3
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    • pp.249-252
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    • 1991
  • Two new metabolites have been characterized from the methylene chloride extracts of Bezoar Bovis, a well known oriental drug : 8-octadecenoic methyl ester and cholesta-3,5-diene. Their structures were deduced from $^1$H-NMR and GC-mass spectra.

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Antioxidant Caffeic acid Derivatives from Leaves of Parthenocissus tricuspidata

  • Saleem, Muhammad;Kim, Hyoung-Ja;Jin, Changbae;Lee, Yong-Sup
    • Archives of Pharmacal Research
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    • v.27 no.3
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    • pp.300-304
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    • 2004
  • Five caffeic acid derivatives; methyl ester of caffeoylglycolic acid (1), dimethyl ester of caffeoyltartaric acid (2), dimethyl ester of caffeoyltartronic acid (3), monomethyl ester of caffeoyltartronic acid (4), methyl ester of caffeic acid (5), and some other secondary metabolites including; quercetin, quercetin 3-O-$\beta$-D-glucuronide methyl ester, kaempferol, 3,5,7,4'-O-tetramethylkaempferol, $\beta$-sitosterol glucoside, 2$\alpha$-hydroxyursolic acid and 2,24-dihydroxyursolic acid, have been isolated and characterized. All the isolated compounds were characterized with the help of NMR spectroscopy and mass spectrometry. Structure of compound 3 was also confirmed by a single X-ray crystallographic technique. Isolates were evaluated for anti-oxidant activities and most of the tested compounds were found to be potent in DPPH free radical scavenging ($IC_{50}{\;}={\;}4.56-14.17{\;}{\mu\textrm{g}}/mL$) and superoxide anion scavenging ($IC_{50}{\;}={\;}0.58-7.39{\;}{\mu\textrm{g}}/mL$) assays.

A Micro-quantification of Abscisic Acid from Plant Tissue by Pentafluorobenzyl Esterification Using GLC (Pentafluorobenzyl ester 화(化)에 의(依)한 미량(微量) Abscisic Acid 의 GLC 분석법(分析法))

  • Jeong, Young-Ho;Hong, Moo-Ki;Song, Byung-Hun
    • Korean Journal of Environmental Agriculture
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    • v.4 no.2
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    • pp.114-117
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    • 1985
  • A new method for micro-quantification of abscisic acid from plant tissue is described. GLC-ECD method of abscisic acid pertafluorobenzyl ester synthesized by reaction of plant extract with pentafluorobenzyl bromide showed higher sensitivity than that of abscisic acid methyl ester, and the detection limit of abscisic acid by the described method was as low as 5 pg.

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Lipase를 이용한 피마자유의 methanolysis

  • Yang, Jung-Seok;Jeon, Gyu-Jong;Heo, Byeong-Gi;Yang, Ji-Won
    • 한국생물공학회:학술대회논문집
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    • 2001.11a
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    • pp.621-634
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    • 2001
  • The characteristics of enzymatic methanolysis of castor oil were investigated as a clean technology. Among 16 lipases tested in this study, Novozym 435 showed the highest activity in methanolysis. Solvents had different effects on the methanolysis of castor oil according to weight percent (wt%) of Novozym 435. Heptane showed best activity with 1 wt% of Novozym 435, while isopropyl ether gave the best yield of ricinoleic acid methyl ester with 0.5 wt% of that. Ricinoleic acid methyl ester was obtained in 86% of yield through the methanolysis of castor oil catalyzed by Novozym 435 (1.0 wt%) during 24hr.

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