• 제목/요약/키워드: methyl esters

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Phytochemical and Antioxidant Activity of Spathodea campanulata P. Beauvois. Growing in Egypt

  • Nazif, Naglaa M.
    • Natural Product Sciences
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    • 제13권1호
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    • pp.11-16
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    • 2007
  • Alcoholic extract of Spathodea campanulata P. aerial parts, and two of the isolated fractions from celite column showed strong antioxidant activity (92, 94 & 89% RSA, Radical Scavenging Activity). Phytochemical investigation of chloroform/EtOAc faction of this column led to the isolation of phenolic acids, caffiec acid (1), and ferulic acid (2), fraction EtOAc/MeOH on further fractionation afforded 3 Flavonoids, kampferol 3-O-glucoside (3), quercetin 3-methyl ether (4) and 8-methoxy kampferol 3-O-glucoside (5). The isolated constituents were identified by co chromatography with authentic samples, TLC, PC., UV, MS and $^1H-NMR$. Also the lipoidal matter of the plant was studied. The unsaponifiable matter was found to be mixture of hydrocarbons from $(C_{14}-C_{28})$, cholesterol, campasterol, stigmasterol, and ${\alpha}-amyrin$. Fatty acid methyl esters were found to contain 12 fatty acids. The fatty acids containing $C_{18}$ farmed ca.65% of the total mixture.

Biosynthesis of Indole-3-acetic Acid in Ginseng Growth-promoting Pseudomonas fluorescens KGPP 207

  • Leonid, N.Ten;Lee, Mee-Kyoung;Lee, Mi Ja;Park, Hoon
    • Journal of Applied Biological Chemistry
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    • 제43권4호
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    • pp.269-272
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    • 2000
  • The ginseng growth-promoting bacterium Pseudomonas fluorescens KGPP 207 synthesized indole-3- acetic acid (IAA) from L-tryptophan, indole-3-pyruvic acid (IPyA), and indole-3-acetaldehyde (IAAld), but not from indole-3-acetamide (lAM) and other intermediates of various IAA biosynthetic pathways in the experiment with indole compound supplemented cell suspensions. TLC, HPLC, and GC-MS analyses revealed the presence of IPyA, indole-3-ethanol, indole-3-lactic acid and its methyl ester, IAA and its methyl, and ethyl esters in the culture supernatant of the bacterium. IAAld was detected in the supernatant using sodium bisulfite and TLC. The results indicate that unlike gall-forming bacteria which can synthesize IAA by lAM, the indole-3-pyruvic acid pathway is the route for IAA biosynthesis in this beneficial strain of P. fluorescens.

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부추(Allium tuberosum Rottler)의 휘발성 향기성분 (Volatile Flavor Components of Leek(Allium tuberosum Rottler))

  • 김경수;박은령;조정옥;김선민;이명렬
    • 한국식품영양과학회지
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    • 제27권4호
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    • pp.563-567
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    • 1998
  • Volatile flavor components of edible portion of leek(Allium tuberosum R.) were extracted by SDE(simultaneous steam distillation and extraction) method using the mixture of n-pentane and diethylether (1 : 1, v/v) as an extract solvent and analyzed by GC-FID and GC/MS. Identification of the volatile flavor components was mostly based on the RI of GC and mass spectrum of GC/MS. A total of sixty-five components from leek extract were classified as 28 sulfur-containing compounds, 12 aldehydes, 9 alcohols, 4 lactones and esters, 3 acids and hydrocarbons, and 2 miscellaneous compouds. The sulfur-containing compounds were predominant in leek extract. Dimethyl disulfide(19.47%) and dimethyl trisulfide(17.38%) were the main compounds and trans-1-propenyl methyl disulfide, trans-2-hexenal and methyl allyl disulfide were also detected large amounts in leek.

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Acylthiocholine들의 합성 (Synthesis of Acylthiocholines)

  • 정대일;이용균
    • 생명과학회지
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    • 제12권1호
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    • pp.26-31
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    • 2002
  • 촉매화된 acetylcholine esterase가수분해의 기질로 사용될 choline ester를 두 가지 방법으로 합성하였다. 먼저, ethylene sulfide를 출발물질로 하여 2-chloroethyl thiohex-anoate, 2-chloroethyl thioheptanoate, 2-chloroethyl thiooc-tanoate를 각각 합성하였고 여기에 trimethyl amine을 첨가하여 hexanonyl thiocholine, octanonyl thiocholine을 합성하였다. 두 번째 방법으로 ethylene sulfide에 dimethyl amine을 첨가시켜 acid anhydride로 acylation 시킨 후 methyl iodide를 첨가하여 heptanoyl thiocholine, decanoyl thiocholine을 합성하였다. 합성된 hexanonyl thiocholine을 기질로 하여 butyrylcholine esterase와의 반응을 연구 하고자 한다. 또한 본 연구에서는 한국 과학 기술원 도핑컨트롤 센터와 연계하여 acetylcholine esterase와 기질인 acyl-thiocholine과의 입체적으로 둘러싸인 acyl-binding site를 분자 조형하고자 노력 중에 있다.

Rate and Product Studies with 2-Methyl-2-Chloroadamantane under Solvolytic Conditions

  • Lee, Young-Hoon;Seong, Mi-Hye;Lee, Eun-Sung;Lee, Yong-Woo;Won, Ho-Shik;Kyong, Jin-Burm;Kevill, Dennis N.
    • Bulletin of the Korean Chemical Society
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    • 제31권5호
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    • pp.1209-1214
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    • 2010
  • Reactions of 2-methyl-2-chloroadamantane (1) in a variety of pure and binary solvents have been studied at various temperatures and pressures up to 80 MPa. The sensitivity (m) to changes in solvent ionizing power of the Grunwald-Winstein equation, and the activation volume (${\Delta}V^{\ddag}$) are calculated from the specific rates. An excellent linear relationship (R = 0.997) for 1, log (k/$k_0$) = $0.80Y_{Cl}$ + 0.11, and the activation volume, ${\Delta}V^{\ddag}$ = -15.2 ~ -10.2 $mL{\cdot}mol^{-1}$ were observed. These values are similar to those for solvolyses of 1-adamantyl halides over the full range of solvents, suggesting that the unimolecular mechanism involving ion pairs is rate-determining. These observations are also compared with those previously reported for the corresponding 1-adamantyl derivatives and chloroformate esters.

유화전이에스테르화에 의한 대두유의 biodiesel화

  • 강영민;김해성
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2001년도 추계학술발표대회
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    • pp.787-790
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    • 2001
  • 대두유의 유화전이에스테르화에 의한 바이오디젤의 생산기술을 연구개발함에 있어서 지방산메틸에스테르의 수율에 미치는 메탄올 몰비, 알칼리 촉매량, 유화제 첨가량 및 반응시간의 영향을 규명하고 유화전이에스테르화 공정의 반응조건을 최적화한 결과, 반응온도 $45^{\circ}C$, 대두유에 대한 에탄올 몰비 1:6, 대두유에 대한 유화제의 첨가량 l(v/v)%에서 0.8wt% 수산화캄륨과 1.2wt% 소디움메톡시드로 대두유를 각각 30분과 50분간 전이에스테르화 하여 $95{\sim}96%$수준의 총괄수율을 얻었다.

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Correlation of the Rates of Solvolysis of Methyl Fluoroformate Using the Extended Grunwald-Winstein Equation

  • Seong, Mi-Hye;Choi, Song-Hee;Lee, Yong-Woo;Kyong, Jin-Burm;Kim, Dong-Kook;Kevill, Dennis N.
    • Bulletin of the Korean Chemical Society
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    • 제30권10호
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    • pp.2408-2412
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    • 2009
  • The specific rates of solvolysis of methyl fluoroformate have been measured at $40.0\;{^{\circ}C}$ in several hydroxylic solvents. Analysis with the extended Grunwald-Winstein equation leads to sensitivities toward changes in solvent nucleophilicity (l) of $1.33\;{\pm}\;0.10$ and toward changes in solvent ionizing power (m) $0.73\;{\pm}\;0.06$. For methanolysis, a solvent deuterium isotope effect of 3.98 is compatible with the incorporation of general-base catalysis into the substitution process. For four representative solvents, studies were made at several temperatures and activation parameters determined. These observations are also compared with those previously reported for alkyl halogenoformate esters and mechanistic conclusions are drawn.

Physiological and Functional Properties of Salicornia herbacea (Tungtungmadi) Leaf Extracts

  • Min, Jin-Gi;Son, Kwang-Tae;Kim, Ji-Hoe;Kim, Tae-Jin;Park, Jeong-Heum
    • Preventive Nutrition and Food Science
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    • 제7권3호
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    • pp.261-264
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    • 2002
  • The physiologically relevant functional properties of various solvent extracts from Salicornia herbacea leaves were investigated by measuring lipid peroxidation, DPPH radical scavenging, nitrite scavenging, and xanthine oxidase inhibition. Ethyl ether, chloroform, ethyl acetate and n-butanol fractions obtained from the 80% aqueous ethanol extracts of Salicornia herbacea leaves showed strong antioxidative activities in linoleic acid methyl esters. Peroxide values (POV) were not significantly different among the samples treated with the different fractions; the incubation time required to reach a peroxide value of 80 meq/kg was about 40 hrs. However, control linoleic acid methyl esters had POV of more than 480 meq/kg after 40 hrs. The DPPH radical scavenging activity of the ethyl acetate fraction was much more effective than diethyl ether, n-butanol, chloroform and water fractions, with an $IC_{50}$/ of 279 $\mu\textrm{g}$/mL, but less effective than ascorbic acid ($IC_{50}$/ : 67 $\mu\textrm{g}$/mL). The nitrite scavenging activities of all fractions increased as pH decreased. Among the fractions, nitrite scavenging activities of diethyl ether and ethyl acetate fractions at pH 1.2 were highest at 59.0 and 56.2%, respectively. The diethyl ether fraction obtained from the 80% aqueous ethanol extract of Salicornia herbacea loaves was the most effective inhibitor of xanthine oxidase of all the solvent extracts at 84% inhibition for a 1 mg/mL concentration. These results suggest that Salicornia herbacea leaf extracts may be effective antioxidants, not only in food stability, but also in human health.

지역별 소규모 농가 생산 전통 고추장의 휘발성 성분에 관한 연구 (Volatile Components of Traditional Gochujang Produced from Small Farms according to Each Cultivation Region)

  • 홍여주;손성혜;김하윤;황인국;유승석
    • 동아시아식생활학회지
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    • 제23권4호
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    • pp.451-460
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    • 2013
  • The purpose of this study is to investigate the volatile compounds of Korean traditional gochujang from various districts. The volatiles from each traditional gochujang are being extracted by simultaneous steam distillation extraction (SDE), and analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Twenty compounds are identified as major volatile components which include 8 esters, 4 alcohols and 4 acids. The most traditional gochujang possesses more volatile components rather than commercial gochujang products. Most acids come from fatty acids and the alcohols derive from the oxidative degradation of linolenic acid. The most abundant volatile compounds for both traditional and commercial gochujang include 10 compounds such as 2-methyl-1-propanol, hexanal, 2-methyl-1-butanol, octanoic acid ethyl ester, as well as the various type of acids and esters. They represent most of the total GC peak areas, respectively. From the results, the characteristics of the flavors for traditional gochujang from each district are not clear but have shown various components than the commercial products.