• 제목/요약/키워드: Trans

검색결과 2,867건 처리시간 0.032초

사각형 $[Pt(II)Cl(PEt_3)_2X]$형태 착물의 계산한 쌍극자모멘트에 대한 리간드의 trans 효과 (X = H, Methyl, Phenyl Group) (The trans Effect of Ligands on the Calculated Dipole Moments for Square Planar $[Pt(II)Cl(PEt_3)_2X]$ The Complexes (X = H, Methyl and Phenyl Group)

  • 안상운;김동희;박의서
    • 대한화학회지
    • /
    • 제28권1호
    • /
    • pp.3-13
    • /
    • 1984
  • trans 사각형 $[Pt(II)Cl(PEt_3)_2X]$형태 착물을 택하여 계산한 쌍극자 모멘트에 대한 리간드의 trans효과를 고찰하여 보았다. 계산한 쌍극자모멘트는 H > Me > Ph > Cl과 같은 순서로 감소하였다. 이 순서는 쌍극자모멘트의 실험치가 감소하는 순서와 일치하며 반응속도에 의하여 결정한 trans 효과가 감소하는 순서와도 일치한다. cis 착물의 계산한 쌍극자모멘트는 trans 착물의 계산한 쌍극자모멘트 보다 훨씬 크며 이것 또한 실험적 사실과 일치한다. 그러나 trans착물의 경우와 달리 몇개의 cis착물의 계산한 쌍극자모멘트는 실험치보다 작은 값을 가진다.

  • PDF

소랄렌의 광화학 반응에 대한 Ab initio 계산 (Ab initio Calculation for Photochemistry of Psoralens)

  • 김자홍;권오형
    • 대한화학회지
    • /
    • 제53권3호
    • /
    • pp.244-256
    • /
    • 2009
  • 소랄렌과 피리디민 염기와의 $C_4$-고리화 부가반응을 통한 가닥내 교차 결합(interstrand crosslinking) 에 의해 만들어진 소랄렌 복합체를 ab initio 방법인 HF와 DFT 6-31G 방법을 이용하여 연구하였다. 소랄렌과 피리디민 염기에 의해 만들어진 광생성물인 8-MOP< >Thy, Ps< >Cyt, Ps< >Thy, Ps< >Ps, Thy< >(3, 4)Ps(12, 13)< >Thy의 최적화된(optimized) 구조를 알 수 있으며, 8-MOP< >Thy은 (trans-syn) 구조, Ps(3, 4)< >Cyt은 (trans-anti) 구조, Ps(12, 13)< >Cyt은 (trans-anti) 구조, Ps(3, 4)< >Thy은 (trans-syn) 구조, Ps(12, 13)< >Thy은 (trans-syn) 구조가 가장 유리하다. Ps(3, 4)< >Thy과 Ps(12, 13)< >Thy의 Gibbs 자유 에너지 변화(${\Delta}{G^{\circ}}$)를 비교하면 Ps(12, 13)< >Thy의 광생성물(단일부가 생성물)이 이루어진 뒤에 Ps(3, 4)< >Thy의 광고리화 부가반응 생성물(이중부가 생성물)을 형성한다는 사실을 알 수 있다. Bispsoralen(psoralen dimer)에서는 Ps(12, 13)< >Ps(12, 13)(trans-anti) 구조가 가장 유리하며, Thy< >(3, 4)Ps(12, 13)< >Thy에서는 (cis syn)(cis anti) 형태가 가장 유리하다.

trans-[Cr$(en)_2Br_2]^+$ 및 trans-$[Cr(tn)_2Br_2]+^$ 착이온의 수화반응에 미치는 압력의 영향 (Pressure Effect on the Aquation of trans-[Cr$(en)_2Br_2]^+$ and trans-$[Cr(tn)_2Br_2]+^$ Ions)

  • 정종재;박경석
    • 대한화학회지
    • /
    • 제30권4호
    • /
    • pp.341-344
    • /
    • 1986
  • 전도도법을 이용하여 trans-[Cr$(en)_2Br_2]^+$ 와 trans-$[Cr(tn)_2Br_2]+^$의 수화반응에 대한 속도상수를 온도와 압력을 변화시키면서 측정했다. 이 때 수화반응의 속도상수는 온도가 증가함에 따라 증가했고 압력이 증가함에 따라 감소하는 경향을 보였다. 이 반응의 활성화부피는 모두 양의 값으로 그 범위는 trans-[Cr$(en)_2Br_2]^+$ 과 trans-$[Cr(tn)_2Br_2]+^$에 대해 각각 1.98~2.30 c$m^3$/mole 및 1.30 ∼ 1.92c$m^3$/mole 이었으며 활성화 엔트로피는 작은 음의 값을 가졌다. 이들 결과로 보아 이 착물들의 수화반응의 메카니즘은 $I_d$매카니즘인 것으로 추정된다.

  • PDF

상업용 훈증제인 Cis-와 Trans-1,3-Dichloropropene(1,3-D)을 차별적으로 분해하는 Bacterial Consortium에 영향을 주는 다양한 이차 탄소원들의 효과 (Influence of a Variety of Second Carbon Substrates on the Bacterial Consortium Differentially Degrading Cis- and Trans-1,3-Dichloropropene (1,3-D))

  • 정근욱
    • 대한환경공학회지
    • /
    • 제22권7호
    • /
    • pp.1243-1252
    • /
    • 2000
  • 휘발성 훈증제인 cis-와 trans-1,3-D의 각각에 대한 분해력 향상은 몇몇 연구자들에 의해 이루어져왔다. 본 연구는 cis-와 trans-1,3-D에 대해 서로 다른 속도에서 각각의 분해력 증진과 미생물과의 관련성을 조사한 것으로, 미생물이 휘발성을 갖는 독성 유기화합물의 분해를 향상시키는 데 관여하고 있음이 관찰되었다. 1,3-D로 야외(field)처리되어 적응되어 왔던 토양으로부터, 1,3-D의 분해가 확인된 토양시료를 채취하여 1,3-D를 분해할 수 있는 혼합 배양세균을 분리하였다. 이렇게 분리된 혼합 배양세균은 cis-1,3-D보다는 trans-1,3-D를 더 빨리 분해 시켰으나, 미생물 성장을 위한 탄소원으로 cis-와 trans-1,3-D만이 제공되었을 때는 분해가 일어나지 않는 반면, 적절한 2차 탄소원들이 존재할 때에는 cis-와 trans-1,3-D를 분해시켰다. 따라서, cis-와 trans-1,3-D의 분해는 공동대사과정(cometabolism)인 것으로 판단된다. 두 이성질체는, 토양여과액(soil leachate), tryptone, tryptophan, alanine이 포함된 시료가 2차 탄소원으로 제공되었을 때에는 분해가 이루어졌으나, 고온고압하에서 멸균시킨 토양추출액(soil extract), glucose, yeast extract 및 indole이 포함된 시료가 2차 탄소원으로 제공되었을 때는 두 이성질체 모두를 분해시키지 못했다. 상업용 훈증제로 이용되는 cis-와 trans-1,3-D를 다른 속도로 개별적으로 분해하는 혼합 미생물군은 형태학적인 구별방법에 의해 4개의 독립된 순수 colony로 구성되어 있는 것으로 관찰되었다.

  • PDF

The Production of Methyl Trans-cinnamate in the Submerged Cultures of Tricholoma matsutake Mycelia

  • Park, Youngki;Lee, Wi Young;Ahn, Jin Kwon
    • Journal of the Korean Wood Science and Technology
    • /
    • 제35권5호
    • /
    • pp.109-117
    • /
    • 2007
  • Methyl trans-cinnamate is a significant flavor compound of Tricholoma matsutake. Attempts were made to produce this compound by culturing the mycelium using submerged culture. No methyl trans-cinnamate could be detected when the mycelium was cultured in the basal liquid medium. However, the addition of Pinus desiflora extracts to the medium, methyl trans-cinnamate was largely produced. To find out compounds or fractions inducing methyl trans-cinnamate, dichloromethane fraction obtained from the wood extracts of P. densiflora was subjected to column chromatography. Three sub-fractions were obtained from the $CH_2CI_2$ fraction. Submerged cultured mycelium treated with sub-fraction 1 has the highest content of methyl trans-cinnamate. Maximum methyl trans-cinnamate $(470.2{\mu}g/g)$ was obtained when the first sub-fraction of dichloromethane fraction of the P. densiflora wood extracts was added to the medium. This indicates that wood extracts of P. densiflora contains inducer of the methyl trans-cinnamate production in the T. matsutake submerged culture.

A Comparative Study of the Anti-Platelet Effects of cis- and trans-Resveratrol

  • Kim, Hwa;Oh, Seok-Jeong;Liu, Yingqiu;Lee, Moo-Yeol
    • Biomolecules & Therapeutics
    • /
    • 제19권2호
    • /
    • pp.201-205
    • /
    • 2011
  • Although various biological activities of resveratrol have been extensively studied, most reports have focused on trans-resveratrol and little attention has been paid to the cis-isomer. In this study, the effect of cis-resveratrol on platelet activity was examined and compared with that of the trans-isomer. Treatment with cis-resveratrol resulted in inhibition of platelet aggregation induced by thrombin, collagen or ADP, which are representative aggregation-inducing agents, and the trans-isomer elicited the same effects. These effects were concentration-dependent in the range of 1-100 ${\mu}M$. However, the potency of the cis-isomer was much lower than that of the trans-isomer; the $IC_{50}$ values for the cis-isomer versus the trans-isomer were $31{\pm}12$ vs $151{\pm}3$, $161{\pm}3$ vs $91{\pm}4$, and $601{\pm}15$ vs $251{\pm}6\;{\mu}M$ for thrombin-, collagen- and ADP-induced aggregation, respectively. These results indicate that cis-resveratrol has a less potent anti-platelet activity, compared with the trans-isomer, and raise the possibility that the biological activities of the cis-isomer may be different from those of the trans-isomer. It will be necessary to evaluate the activity of cis-resveratrol independently of the trans-isomer.

Tetrahymena thermophila의 group I intron에 의한 trans-splicing 반응에 미치는 표적 RNA 구조의 영향분석 (Effects of Substrate RNA Structure on the Trans-splicing Reaction by Group I Intron of Tetrahymena thermophila)

  • 이성욱
    • 미생물학회지
    • /
    • 제35권3호
    • /
    • pp.211-217
    • /
    • 1999
  • 표적 RNA 의 구조가 Tetrahymena thermophila 의 group I intron 에 의한 trans-splicing 반응에 미치는 영향을 분석하기 위해 강력한 stem-loop 형태의 안정된 구조를 갖고 있는 표적 RNA mapping 분석 방법을 이용한 결과 in vitro 뿐만 아니라 in vivo 에서도 stem 부위의 염기들에 반해 loop 부위의 염기들이 ribozyme 에 의해 잘 인지되었으며 이러한 결과는 그러한 부위들을 인지할 수 있는 ribozyme 들에 의한 trans-cleavage 그리고 trans-splicing 반응을 수행함으로써 검증하였다. 또한 이러한 trans-splicing 반응은 정확하게 일어남을 반응 산물의 염기서열 결정을 통해 확인하였다. 따라서 표적 RNA 의 구조가 in vitro 및 in vivo 에서의 ribozyme 활성에 매우 중요한 요인임을 확인하였다.

  • PDF

마르코스 노박(Marcos Novak)의 트렌스 건축(Trans Architecture) 개념에 관한 연구 (A Study on the concept of 'Trans Architecture' in Marcos Novak)

  • 이규홍;김개천
    • 한국실내디자인학회논문집
    • /
    • 제15권4호
    • /
    • pp.46-54
    • /
    • 2006
  • The present study examined Marcos Novak, a digital architect who has researched digital architecture and produced related works since the early 1990s. Starting from digital ideas originating from science and mathematics, he pursued 'trans architecture' based on the concept of 'architecture beyond the boundary of architecture' and 'architecture as invisible foundation.' His concept of 'trans architecture' is considered an important viewpoint in expressing the architecture of a diversified and hybridized age like today. The objective of this study was to understand the concepts of Allobio and Eversion, which are important digital terms forming the background of Novak's trans architecture, and to analyze architecture philosophy and architecture design concepts observed in his works through Novak's digital terminology centering on the concept of trans architecture pursued by him. Through this, we purposed to analyze the concept of architectural space, methods of form creation and the characteristics of trans architecture space, which were unique to Novak, the leader of digital architecture, and ultimately to provide basic materials on Novak. Novak's trans architecture represents digital architecture in the contemporary diversified and hybridized age, and his works involve various different digital elements and ideas, scientific paradigms, mathematic algorithms, 4 dimensional geometry, etc. In this sense, he is regarded as a prominent leading advocate of digital architecture.

Effects of Concentrate to Roughage Ratio on the Formation of cis-9, trans-11 CLA and trans-11-Octadecenoic Acid in Rumen Fluid and Plasma of Sheep When Fed High Oleic or High Linoleic Acid Oils

  • Wang, J.H.;Choi, S.H.;Song, M.K.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제16권11호
    • /
    • pp.1604-1609
    • /
    • 2003
  • A metabolism trial with four ruminally fistulated sheep was conducted in a $4{\times}4$ Latin square design to examine the effect of concentrate to roughage ratio (70:30 vs. 85:15) and oil source (soybean oil vs. rapeseed oil) on the ruminal fermentation pattern and $C_{18}$-fatty acids composition including trans11-$C_{18:1}$ (trans11-ODA) and cis9, trans11-18:2 (cis9, trans11-CLA) in the rumen fluid and plasma. Oil was added to the concentrate at 5% level of the total diet (DM basis) and chopped rye grass hay was fed as roughage. An increased level of concentrate (85%) within supplemented oil slightly lowered pH but increased ammonia concentration. Supplementation of rapeseed oil relatively increased pH and ammonia concentration. Higher concentrate level resulted in increased tendencies of total VFA concentration while oil source did not affect the total VFA concentration and VFA proportion. Whole tract digestibilities of DM, CP, EE, NDF and OM in diets slightly increased at higher concentrate level. Proportions of oleic acid ($C_{18:1}$) and linoleic acid ($C_{18:2}$) in the rumen fluid were influenced by the fatty acid composition of oil source but oil source did not affect the in vitro formations of trans11-ODA and cis9, trans11-CLA. Slightly increased trans11-ODA and cis9, trans11-CLA proportions, however, were observed from the sheep fed high roughage diet supplemented with both soybean oil and rapeseed oil. The $C_{18:1}$ and $C_{18:2}$ composition in supplemented oils responded to those in plasma of sheep. Effects of concentrate to roughage ratio and oil source on trans11-ODA and cis9, trans11-CLA proportions in plasma were found to be small. Proportion of cis9, trans11-CLA in plasma tended to be increased from the sheep fed high roughage diet and collection time at 9h post feeding.

유지의 가열 및 저장에 따른 Trans 지방산 생성에 관한 연구(I) -일부 이화학적 특성 및 Trans 지방산 함량변화를 중심으로- (A Study on the Formation of Trans Fatty Acids with Heating and Storage of Fats and Oils (I) - The Change of Physicochemical Characteristics and Total Trans Fatty Acids Content -)

  • 김덕숙;구본순;안명수
    • 한국식품조리과학회지
    • /
    • 제6권2호
    • /
    • pp.37-50
    • /
    • 1990
  • The cause and the degree of the cis to trans isomerization were investigated about soybean oil (SBO), corngerm oil (CGO), cottonseed oil (CSO), margarine (MG) and shortening (ST). All samples treated with various conditions were analyzed to determine physicochemical characteristics (AV, POV, IV, RI), fatty acid composition, total trans fatty acid content and change of trans fatty acid composition by GLC, IR and HPLC. The results were obtained as follows; 1. Physicochemical constants were changed with a gentle slope according to incubating period at 40${\pm}$2$^{\circ}C$ and physicochemical constants of margarine and shortening were changed, significiantly. 2. The saturation degree in the unsaturated fatty acid composition determined by GLC gradually were increased during incubation and heating periodically. For palmitic-and stearic acid content at the samples stored in the incubator, the saturation degrees were gradually increased. But for the case of heat treatment, they were increased more rapidly than other fatty acids. 3. Total trans fatty acid contents in each samples were determined by GLC, IR and HPLC, the amount of trans fatty acids were measured with discrepancy. It was caused by deviation of analytical instruments, methods and the kinds of samples. Trans fatty acids were measured more definitly in IR more than GLC and HPLC. On the other hand, total trans fatty acid contents in average levels for SBO, CGO, CSO, MG and ST stored for 35 days and heated for 24 hours were 1.3%, 1.1%, 0.9%, 22.6% and 13.8%, and 3.6%, 3.0%, 2.8%, 41.2% and 20.8%, respectively.

  • PDF