• 제목/요약/키워드: $K_{trans}$

검색결과 1,862건 처리시간 0.023초

$TiO_2$-Mediated Photoreactions of Cinnamic Acid and Related Compounds in Methanol

  • Kim, Sung-Sik;Kim, Hyun-Jin;Lee, Hye-Jong;Park, Sang-Kyu
    • Journal of Photoscience
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    • 제10권2호
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    • pp.181-184
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    • 2003
  • Photochemical reactions of some organic molecules on titanium dioxide were investigated in methanol. A methanolic solution of trans-cinnamic acid and titanium dioxide was irradiated with 300 nm UV lamps for 24 h to afford methyl cinnamate. In the case of trans-cinnamamide, the major product was found to be 3-phenylpropionamide, i.e., a saturation product of ethylenic double bond. However, irradiation of urocanic acid, caffeic acid, ethyl cinnamate, trans-chalcone, trans-cinnamonitrile, trans-stilbene or trans, trans-1,4-diphenyl-1,3-butadiene on titanium dioxide under the same conditions did not give any noticeable products. Meanwhile, when irradiated some aromatic aldehydes, such as trans-cinnamaldehyde, l-naphthaldehyde, and 2-naphthaldehyde in methanol, vicinal diols and alcohols derived from the diols were produced. On the other hand, irradiation of 9-anthraldehyde and titanium dioxide in methanol afforded only alcohols, in which diol was not observed.

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Microbial Metabolism of trans-2-Dodecenal

  • Kim, Hyun-Jung;Park, Hae-Suk;Lee, Ik-Soo
    • Natural Product Sciences
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    • 제17권1호
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    • pp.19-22
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    • 2011
  • Microbial metabolism of trans-2-dodecenal (1) was studied. Screening studies have revealed a number of microorganisms that are capable of metabolizing trans-2-dodecenal (1). Scale-up fermentation with Penicillium chrysogenum resulted in the production of two microbial metabolites. These metabolites were identified using spectroscopic methods as trans-2-dodecenol (2) and trans-3-dodecenoic acid (3).

Gas Chromatographic Method for Analysis of Fatty Acids in Milk Fat with a Single Injection

  • Hwang, Keum-Taek;Shin, Min-Kyeong
    • Preventive Nutrition and Food Science
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    • 제11권3호
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    • pp.253-256
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    • 2006
  • The purpose of this study was to develop a gas chromatographic (GC) method to analyze fatty acids in milk fat with a single injection. The single-injection GC method we developed for analyzing fatty acid composition can separate a wide range of fatty acid methyl esters from butyric acid to docosahexaenoic acid. It separated 6 isomers of 18:1 (cis-6, cis-9, cis-11, trans-6, trans-9 and trans-11), 4 isomers of 18:2 (cis-9-cis-12, trans-9-trans-12, cis-9-trans-12 and trans-9-cis-12), and 4 isomers of conjugated 18:2 (cis-9- trans-11, trans-9-cis-11, cis-10-trans-12 and trans-10-cis-12).

목재부후균에 의한 trans,trans-farnesol의 생물변환 (Biotransformation of trans,trans-farnesol by Wood Rot Fungi)

  • 김영훈;이수연;박미진;최인규;이재원
    • 미생물학회지
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    • 제48권1호
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    • pp.37-41
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    • 2012
  • 본 연구에서는 sesquiterpene류의 생물학적 변환을 위한 생촉매로서 목재부후균을 선발하고 생물변환 가능성을 확인하였다. Sesquiterpene류 합성 전구체로 알려진 trans,trans-farnesol을 기질로 하여 총 19종의 목재부후균에 대해여 저항성 실험을 실시하였다. 기질의 농도를 달리하여 저항성 테스트를 실시하여 생물변환 가능성을 갖는 5종의 균주를 선발하였으며 선정된 균주를 이용하여 액체배지 조건에서 trans,trans-farnesol의 생물변환을 시도하였다. GC/MS를 이용하여 분석한 결과 Laetiporus sulphureus var. miniatus (jungh) Imaz, Coriolus versicolor (L. Fr). Prlar, Fomitopsis pinicola, Lampteromyces japonicas 등 4개의 균주에서 각각 nerolidol, eicosane, isoborneol, isocyclocitral 등의 대사산물을 확인할 수 있었다. 이와 같은 결과로 sesquiterpene류의 생물학적 변환을 위한 생촉매로서 목재부후균의 가능성을 확인하였다.

Analysis of Trans Fat in Edible Oils with Cooking Process

  • Song, Juhee;Park, Joohyeok;Jung, Jinyeong;Lee, Chankyu;Gim, Seo Yeoung;Ka, HyeJung;Yi, BoRa;Kim, Mi-Ja;Kim, Cho-il;Lee, JaeHwan
    • Toxicological Research
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    • 제31권3호
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    • pp.307-312
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    • 2015
  • Trans fat is a unsaturated fatty acid with trans configuration and separated double bonds. Analytical methods have been introduced to analyze trans fat content in foods including infrared (IR) spectroscopy, gas chromatography (GC), Fourier transform-infrared (FT-IR) spectroscopy, reverses-phase silver ion high performance liquid chromatography, and silver nitrate thin layer chromatography. Currently, FT-IR spectroscopy and GC are mostly used methods. Trans fat content in 6 vegetable oils were analyzed and processing effects including baking, stir-frying, pan-frying, and frying on the formation of trans fat in corn oil was evaluated by GC. Among tested vegetable oils, corn oil has 0.25 g trans fat/100 g, whereas other oils including rapeseed, soybean, olive, perilla, and sesame oils did not have detectable amount of trans fat content. Among cooking methods, stir-frying increased trans fat in corn oil whereas baking, pan-frying, and frying procedures did not make changes in trans fat content compared to untreated corn oils. However, the trans fat content was so low and food label can be declared as '0' trans based on the regulation of Ministry of Food ad Drug Safety (MFDS) (< 2 g/100 g edible oil).

Methyl Linoleate에 대한 Phenol성 물질의 항산화성과 산화 생성물 (Antioxidative Effectiveness and Oxidized Products in Mixture of Methyl Linoleate and Phenolic Compounds)

  • 김정숙;이기동;권중호;윤형식
    • 한국식품과학회지
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    • 제25권4호
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    • pp.379-385
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    • 1993
  • Phenol성 물질로서 hydroxyl기가 두개인 caffeic acid와 세개인 phloroglucinol을 methyl linoleate에 첨가하여 산화시키면서 활성화 효과와 산화생성물을 분석하였다. Methyl linoleate에 대한 $37^{\circ}C,\;3{\sim}9$일간의 산화반응에서 caffeic acid 및 phloroglucinol 첨가군은 ${\alpha}-tocopherol$ 첨가군에 비해 높은 항산화성을 나타내었다. 이 때 산화생성물로서는 methyl linoleate(ML)군은 methyl-8-(2-furyl)-octanoate, 9,13-trans, cis hydroperoxide isomer 9,13-trans, trans hydroperoxide isomer 및 9-TMSO-12, 13-epoxy-10-octadecenoate로 나타났으며, 기간이 경과함에 따라 9,13-trans, trans isomer에 대한 9,13-trans, cis isomer의 비율이 낮아졌다. Caffeic acid 첨가군(CML)에서는 methyl-8-(2-furyl)-octanoate, 9-trans, cis hydroperoxide isomer 및 9-trans, trans hydroperoxide isomer였으며, 13-hydroxy isomer는 검출되지 않았다. Caffeic acid의 농도를 높일수록 9-trans, trans isomer에 대한 9-trans, cis isomer의 비율이 높아지는 것으로 나타났으며, 이 때 가장 주된 산화물인 caffeic quinone이 생성되는 것으로 보아 caffeic acid와 같은 o-dihydroxy cinnamate들은 lipid media에서 산화가 쉽게 일어나는 것으로 나타났다. 또한 phloroglucinol 첨가군(PML)의 산화 생성물들은 methyl-8-(2-furyl)-octanoate, 9-trans, cis hydroperoxide isomer, 9-trans, trans hydroperoxide isomer 및 9-hydroxy-12,13-epoxy-10-octadecenoate로서 CML군과 유사한 경향을 보였으나 phloroglucinol은 반응 9일째에도 산화되지 않았다.

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일반 고체지와 저트랜스 고체지를 이용한 베이커리 제품의 특성 비교 (Comparison of the Bakery Products Made Commercial Fat or Low Trans Fat)

  • 황부연;김유미;이기택
    • 동아시아식생활학회지
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    • 제17권1호
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    • pp.64-71
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    • 2007
  • Breads and cookies made with conventional or low-trans fat(margarine and shortening) were analyzed by determining their trans fat content, textural properties and color values after production. The trans fatty acids content in conventional margarine was three times higher than that of low-trans margarine. Moreover, the content of trans fatty acids in the conventional shortening was 49 times higher than that of low-trans shortening. The trans fatty acid contents of cookies and breads made with low-trans fat, can be reduced more than 2 to 75 times compared to cookies and breads made with conventional fat. In the produced cookies and breads, the color values and textural properties(hardness, springiness, cohesiveness, gumminess and chewiness) did not differ significantly when the conventional fat or low-trans fat was used.

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$trans-[Cr(tmd)_2F_2]^+$$trans-[Cr(tmd)_2FCl]^+$ 착이온의 수화반응에 미치는 압력의 영향 (Pressure Effect on the Aquation of $trans-[Cr(tmd)_2F_2]^+\;and\;trans-[Cr(tmd)_2FCl]^+$ Ions)

  • 정종재;김한태;백성오
    • 대한화학회지
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    • 제33권2호
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    • pp.164-167
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    • 1989
  • 분광광도법을 이용하여 $trans-[Cr(tmd)_2FX]^+(X=F^-,\;Cl^-)$ 착이온의 압력과 온도변화에 따른 수화반응의 속도상수를 구하였다. 속도상수의 변화로부터 열역학적 인자를 구하고 이 값을 이용하여 두 착물의 반응메카니즘을 구하였다. 수화반응의 속도는 온도와 압력이 증가함에 따라 증가하였으며, 이 반응의 활성화엔트로피와 활성화부피는 각각 $trans-[Cr(tmd)_2F_2]^+$착이온의 경우 5.2eu와 $-3∼-2\;cm^3mol^{-1}$ 이고 trans-[Cr(tmd)_2FCl]^+$ 착이온의 경우는 -16.62eu와 $-8∼-7\;cm^3mol^{-1}$ 이었다. 이 값들로 보아 $trans-[Cr(tmd)_2F_2]^+$착이온의 수화반응은 교환회합(Ia) 메카니즘으로 진행되고 $trans-[Cr(tmd)_2FCl]^+$ 착이온의 수화반응은 해리(D) 메카니즘으로 진행되는 것으로 생각된다.

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Preparation of a Large Quantity of CIS-9, trans-11 and trans-10, cis-12 Conjugated Linoleic Acid(CLA) Isomers from SYnthetic CLA

  • Kim, Seck-Jong;Park, Kyung-Ah;Park, Jung-H.Y.;Kim, Jeong-Ok;Ha, Yeong-Lae
    • Preventive Nutrition and Food Science
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    • 제5권2호
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    • pp.86-92
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    • 2000
  • Conjugated linoleic acid(CLA) refers to a collective term of positional and geometric isomers of linoleic acid, which are different in their biological activities. The predominant isomer of CLA in animal tissues is cis-9, trans-11; smaller amounts of trans-10, cis-12 CLA isomers, CLA methyl ester (CLA-ME) was chemically syn-thesized from linoleic acid by the alkaline isomerization method. The synthetic CLA-ME, mainly composed of cis-9, trans-11 CLA and trans-10, cis-12 CLA, was dissolved in acetone, stored at 68$^{\circ}C$ for 1 day, and the supernatant(cis-9, trans-11 CLA-Me) was separated from the precipitate (trans-10, cis-12 CLA-Me). After the processes were repeated three times at -68$^{\circ}C$, the whole processes were repeated three times at -71$^{\circ}C$ in order to increase the purity of these two isomers. The cis-9, trans-11 CLA-Me and trans-10, cis-12 CLA isomers were further purified by the urea adduct. Purities of the cis-9, trans-11 CLA-Me and trans-10, cis-12 CLA-Me were 90.3 and 99.9%, respec-tively. This method could be employed for the preparation of a large quantity of highly purified cis-9, trans-11 CLA-Me or trans-10, cis-12 CLA-Me from synthetic CLA-Me.

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Effect of Forage to Concentrate Ratio and Monensin Supplementation on cis-9, trans-11 Conjugated Linoleic Acid and trans-11 Octadecenoic Acid Concentrations of Ruminal Contents and Plasma in Sheep

  • Zhang, Yuzhi;Kong, Xianghao;Zhu, Xiaoping;Wang, Runlian;Yan, Yichai;Jia, Zhihai
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권5호
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    • pp.699-704
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    • 2006
  • Twenty-four cannulated Small-tailed Han${\times}$Poll Dorset wethers (BW $47.5{\pm}2.1kg$) were used to determine the effects of forage to concentrate ratio (40:60 vs. 70:30), monensin supplementation (0, 15 or 30 ppm, DM basis) and interactions of these two factors on cis-9, trans-11 conjugated linoleic acid (cis-9, trans-11 CLA) and trans-11 octadecenoic acid (trans11-$C_{18:1}$) concentrations in ruminal contents and plasma in sheep. The experiment was designed as a $2{\times}3$ factorial. The diet contained Chinese wild rye grass hay (Aneurolepidium Chinese), cracked corn, soybean meal, NaCl, limestone and trace mineral premix. Dietary crude fat and linoleic acid ($C_{18:2n-6}$) were adjusted with soybean oil to about 7.0% and 24.0 mg/g (DM basis), respectively. High forage diets increased (p<0.001) the concentrations of trans11-$C_{18:1}$ and cis-9, trans-11 CLA in ruminal contents and plasma. Monensin supplementation increased (p<0.001) the concentration of trans11-$C_{18:1}$ in ruminal contents, but had no effect on that of cis-9, trans-11 CLA. Concentrations of trans11-$C_{18:1}$ (p<0.019) and cis-9, trans-11 CLA (p<0.022) in plasma increased with dietary monensin levels. Interactions of forage: concentrate ratio and monensin level tended to affect the concentrations of trans11-$C_{18:1}$ (p<0.091) and $C_{18:2n-6}$ (p<0.083) in ruminal contents. Increasing forage levels increased the concentrations of trans11-$C_{18:1}$ and cis-9, trans-11 CLA in the rumen. Supplementing with monensin increased the ruminal production of trans11-$C_{18:1}$ and concentrations of trans11-$C_{18:1}$ and cis-9, trans-11 CLA in plasma.