• 제목/요약/키워드: isomer

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Determination of Stereochemical Structure of a Grandidentatin Isomer from Populus alba × glandulosa Bark (현사시나무 수피에서 분리한 Grandidentatin Isomer의 입체구조결정)

  • Kwon, Dong-Joo;Kim, Hyun-Seok;Lee, Phil-Ho;Bae, Young-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.1
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    • pp.114-120
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    • 2009
  • The bark of Populus alba ${\times}$ glandulosa was collected, air-dried and extracted with 70% aqueous acetone. Then it was successively partitioned with n-hexane, $CH_2Cl_2$, EtOAc and $H_2O$. Repeated Sephadex LH-20 column chromatography and preparative TLC on the EtOAc soluble fraction gave a grandidentatin isomer. The structure was elucidated as grandidentatin A (cis-2-hydroxycyclohexyl 6-O-p-coumaroyl-${\beta}$-D-glucopyranoside) on the basis of spectroscopic evidences such as $^1H$-NMR, $^{13}C$-NMR, 2D-NMR and MALDI TOF-MS spectrum followed by acid hydrolysis. Grandidentatin A was identified here for the first time in Populus alba ${\times}$ glandulosa bark, and to the bset of our knowledge it has not been reported in any other literature.

Effect of Isomers of Conjugated Linoleic Acid on Porcine Preadipocyte Differentiation (Conjugated Linoleic Acid(CLA) 이성체가 돼지 지방전구세포의 분화에 미치는 영향)

  • Moon, H.S;Chung, C.S.
    • Journal of Animal Science and Technology
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    • v.46 no.6
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    • pp.967-974
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    • 2004
  • The current study was undertaken to determine the effect of various conjugated linoleic acid (CLA) isomers on differentiation of pig preadipocyte during culture. Preadipocyte(stroma-vascular cell) was isolated from the backfat of newborn pigs and cultured to differentiate into mature fat cell. Different doses of CLA isomers were treated to the culture media at different times. Cell differentiation was determined by measuring the glycerol3-phosphate dehydrogenase activity of the cultured preadipocytes. Twenty and fifty $\mu$M of trans110_cis 12 isomer of CLA inhibited differentiation of pig preadipocyte whereas cis9-cis II isomer stimulated the differentiation. Both cis9-transII and trans9-trans11 isomers showed no effect. Effect of CLA isomer was more evident at the early stage of culture(day 0-8), than the late stage(day 8-14). These results suggest that each CLA isomer has different effect on pig preadipocyte differentiation.

Change of Fragrant Components by Flowering Stages in Lilium Oriental Hybrid 'Casa Blanca' (오리엔탈 나리 '카사블랑카'의 개화단계별 향기성분 변화)

  • Rho, A Ran;Pak, Chun Ho
    • Horticultural Science & Technology
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    • v.19 no.2
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    • pp.163-169
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    • 2001
  • This experiment was conducted to find out suitable extraction time of available fragrant component in Lilium Oriental Hybrida 'Casa Blanca' based on qualitative and quantitative variation of its fragrant component in its flowering stages. The content of essential oil in its flowering stages increased with the progress of flowering stages except flower bud stage and it had the most oil content in its stage after full bloom. The analysis of the essential oil in Lilium Oriental Hybrida 'Casa Blanca' in its flowering stages shows that its main constituents were farnesol (18.96%), benzyl salicylate (13.81%), butyl-hydroxy toluene (12.87%), geranyl linalool isomer (7.46%), isoeugenol (7.17%) in its each stage. Benzenoids had much content at half bloom stage and full bloom stage while fatty acid derivatives had much content at initial flowering stage and after flowering stage. Most benzenoids such as butyl-hydroxy toluene and isoeugenol, which are some of main constituents of Lilium Oriental Hybrida 'Casa Blanca' had strong antioxidant effect. So they were expected to be used as antioxidant agents for food, feed, vegetable oil. The content of monoterpene compounds like geranyl linalool isomer increased at its later stage. Sesquiterpene such as farnesol, which is main component of lily existed only at full bloom stage. Therefore farnesol and geranyl linalool isomer of Lilium Oriental Hybrida 'Casa Blanca' are expected to be used for important spices with good fragrance. The suitable extraction time for the usable main constituents of Lilium Oriental Hybrida 'Casa Blanca' is as follows; farnesol and benzyl salicylate: at full bloom stage, butyl-hydroxy toluene: at half bloom stage, geranyl linalool isomer and isoeugenol: at stage after full bloom. Finally there was variation in essential oil components and contents of Lilium Oriental Hybrida 'Casa Blanca' in its flowering stages and they are expected to be used usefully for flavor industry, food industry, aromatherapy, when they are extracted at their suitable extraction time.

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Alkylation of Benzene over Zeolites with 1-Dodecene (제올라이트 촉매상에서 1-Dodecene을 이용한 벤젠의 알킬화 반응)

  • Shin, Heung-Seon;Lee, Dong-Kyu
    • Journal of the Korean Applied Science and Technology
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    • v.16 no.2
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    • pp.117-125
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    • 1999
  • The alkylation benzene with 1-dodecene of Mordenite, Zeolite ${\beta}$ and Zeolite Y was studied in the stirring batch reactor. The kinds of zeolites were found to have influenced the reaction conversion and distribution of phenyldodecane isomer in the product. Compared to the alkylation conducted over Zeolite Y and Zeolite ${\beta}$, the alkylation over Mordenite exhibited higher distribution of 2-phenyldodecane and the alkylation conducted over Zeolite Y and Mordenite, the alkylation over Zeolite ${\beta}$ exhibited higher distribution of heavy alkylate which formed through oligomerization reaction readily deactivated the Lewis acid sites. A special feature of the effect of the benzene to 1-dodecene ratio the reaction conversion and selectivity of phenyldodecane isomer was found. At alkylation of benzene with 1-dodecene over Zeolite ${\beta}$, when the catalyst content in the system was high, the reaction will reach the optimal conversion at the higher B/D. When the benzene to 1-dodecene ratio was high, the selectivity of phenyldodecane isomer is high. It was also found that at the similar reaction conversion there was the same product distribution regardless of D/C ratio.

Multi-analysis of the Organochlorine Pesticides in Ginseng at Gyeongbuk, Korea (경북지역 인삼 중 유기염소계 농약의 다성분 분석)

  • Park Moon-Ki;Kim Jung-Ho
    • Journal of Environmental Science International
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    • v.14 no.2
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    • pp.193-199
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    • 2005
  • To obtain the residual organochlorine pesticides in the ginseng, the methods of multi-analysis for BHC's isomer, DDT's isomer and other organochlorine pesticides by GC-ECD are surveyed. The relative retention time for $\alpha-BHC,\;\beta-BHC,\;\delta-BHC\;and\;\gamma-BHC$ is 1.000, 1.025, 1.034 and 1.056, respectively. The relative retention time for o,p-DDE, p,p-DDE, o,o-DDD, o,p-DDT, o,p-DDD, and p,p-DDT is 1.199, 1.230, 1.242, 1.286, 1.329 and 1.333, respectively. The BHC isomers, DDT's isomer and other organochlorine pesticides are separated with multianalysis condition. The qualified defection concentration for $\alpha-BHC$, Quintozene, Aldrin, Captan, $\alpha-Endosulfan$, and Dieldrin is 0.95ng/g, 0.27ng/g, 1.04ng/g, 0.63ng/g, 0.55ng/g and 0.62ng/g, respectively. The qualified defection concentration for Fenhexamid, Endrin, $\beta-Endosulfan$, o,p-DDT, Endosulfan-sulfate is 5.71ng/g, 0.61ng/g, 0.48ng/g, 0.44ng/g and 0.51ng/g, respectively. BHC, Aldrin, Dieldrin, Endrin and DDT, which were Korea Food & Drug Administration advisory pesticides, are not detected in soil environment. Also it's residual organochlorine pesticides are not polluted in the ginseng on Sangju Korea.

Characterization of Bioactive Compounds of Domestic Tomato Varieties (국내산 토마토 품종의 생리활성 물질의 특성)

  • Ahn, Jun-Bae
    • Culinary science and hospitality research
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    • v.24 no.1
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    • pp.63-72
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    • 2018
  • The aim of this study was to investigate bioactive compounds from three domestic tomato varieties (Rafito, Momotaro TY Winner, and Medison). Lycopene, ${\beta}-carotene$ and polyphenols were quantified and identified using HPLC and LC-MS/MS. The levels of lycopene ranged from 28.36 mg/100 g to 60.18 mg/100 g. The content of ${\beta}-Carotene$ ranged from 2.00 mg/100 g to 2.92 mg/100 g. Ten kinds of polyphenol compounds were identified: caffeic acid-hexose isomer (I), caffeic acid-hexose isomer (II), 3-caffeoylquinic acid, 5-caffeoylquinic acid, caffeoylquinic acid isomer, quercetin-3-apiosylrutinoside, quercetin-3-rutinoside, di-caffeoylquinic acid, tri-caffeoylquinic acid, and naringenin chalcone. The level of 5-caffeoylquinic acid was the highest in domestic tomato varieties, ranging from 12.71 mg/100 g to 28.40 mg/100 g. The content of quercetin-3-rutinoside ranged from 3.74 mg/100 g to 17.64 mg/100 g. The contents of 3-caffeoylquinic acid and quercetin-3-apiosylrutinoside were 1.01~2.31 mg/100 g and 5.84~6.83 mg/100 g, respectively. Arrestingly naringenin chalcone was found only in Medison variety (36.82 mg/100 g). These results revealed that domestic tomato can be a good source of bioactive compounds for human health.

Conjugated Linoleic Acid Reduction of Vascular Endothelial Growth Factor Expression in Murine Mammary Tumor Cells through Alteration of Prostaglandin E2

  • Kim, Jung-Hyun;Hubbard, Neil E.;Lim, Debora;Erickson, Kent L.
    • Preventive Nutrition and Food Science
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    • v.11 no.1
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    • pp.1-5
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    • 2006
  • Conjugated linoleic acid (CLA) is a group of positional and geometric isomers of linoleic acid that have been used to reduce the incidence, growth and metastasis of breast, colon, prostate and gastric cancer in animals. CLA could reduce tumor growth by altering angiogenesis; a process requiring associated angiogenic factors such as vascular endothelial growth factor (VEGF). In this study, we determined whether CLA could modulate the expression of VEGF in murine mammary tumor cells and adipocytes. The c9, t11-CLA isomer reduced VEGF transcripts and protein when mammary tumor cells were stimulated with PMA. That isomer also reduced VEGF expression in un stimulated mouse 3T3-L1 adipocytes. Since VEGF can be regulated by cyclooxygenase-2 (COX-2), we determined whether CLA could alter COX-2 enzyme expression and $PGE_2$ production. The c9, t11-CLA isomer reduced not only COX-2 enzyme expression but also $PGE_2$ production. Thus, c9, t11-CLA could modulate neovascularization by alteration of VEGF expression from mammary tumor cells and adipocytes by reducing COX-2 metabolites.

Comparative Kinetic Studies of Two Staphylococcal Lipases Using the Monomolecular Film Technique

  • Sayari, Adel;Verger, Robert;Gargouri, Youssef
    • BMB Reports
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    • v.34 no.5
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    • pp.457-462
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    • 2001
  • Using the monomolecular film technique, we compared the interfacial properties of Staphylococcus simulans lipase (SSL) and Staphylococcus aureus lipase (SAL). These two enzymes act specifically on glycerides without any detectable phospholipase activity when using various phospholipids. Our results show that the maximum rate of racemic dicaprin (rac-dicaprin) hydrolysis was displayed at pH 8.5, or 6.5 with Staphylococcus simulans lipase or Staphylococcus aureus lipase, respectively The two enzymes interact strongly with egg-phosphatidyl choline (egg-PC) monomolecular films, evidenced by a critical surface pressure value of around $23\;mN{\cdot}m^{-1}$. In contrast to pancreatic lipases, $\beta$-lactoglobulin, a tensioactive protein, failed to inhibit Staphylococcus simulans lipase and Staphylococcus aureus lipase. A kinetic study on the surface pressure dependency, stereoselectivity, and regioselectivity of Staphylococcus simulans lipase and Staphylococcus aureus lipase was performed using optically pure stereoisomers of diglycerides (1,2-sn-dicaprin and 2,3-sn-dicaprin) and a prochiral isomer (1,3-sn-dicaprin) that were spread as monomolecular films at the air-water interface. Both staphylococcal lipases acted preferentially on distal carboxylic ester groups of the diglyceride isomer (1,3-sn-dicaprin). Furthermore, Staphylococcus simulans lipase was found to be markedly stereoselective for the sn-3 position of the 2,3-sn-dicaprin isomer.

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A Study for the Standardization of Elsholtzia ciliata (Thunb.) Hylander and Elsholtzia splendens Nakai ex F. Maekawa

  • Yun, Jong-Seong;Lee, Sang-In;Rhee, Jae-Seong;Park, Ho-Koon
    • The Journal of Korean Medicine
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    • v.19 no.1
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    • pp.19-26
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    • 1998
  • The purpose of present study is to clarify the differences between EIslwitzia Ciliata (Thunb.) Hylander(향유) and Elsholtzia splendens Nakai ex F. Maekawa (꽃향유) for standardization and the proper usage as medicinal herbs. The major ingredients of both species were isolated by distillation and extraction. The qualitative and quantitative analyses of major distillates were carried out by the use of GC/MS. There was a significant difference between the components of Elsholtzia ciliata and Elsholtzia splendens in the aspects of major components. Several common ingredients were identified as linalool, cumene, elsholtzia ketone, naginata ketone isomer, naginata ketone, myristicin, and sesquiterpene alcohol. Comparison between Elsholtzia. ciliata and Elsholtzia splendens was done in the aspect of major compounds. Myristicin (33.7%) has been shown to be the major component in Elsholtzia ciliata whereas naginata ketone isomer (26.1%) was believed to be a major ingredient in Elsholtzia splendens. The elsholtzia ketone was also one of the major differentiating factors between Elsholtzia splendens and Elsholtzia ciliata, and the quantity is 15.1% in Elslwltzia splendens compared to 2.87% in Elsholtzia ciliata. Moreover, in the Elsholtzia splendens, 4- vinylguaiacol and isoosmorhizole were absent, but both compounds were present in the EIsholtzia ciliata.

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Isomer Formation in the Chlorination of Highmolecular Paraffinic Hydrocarbons by Various Halogenating Agents (여러 종류의 할로겐 화합물과 고분자량 파라핀계 탄화수소의 염소화에서 생기는 이성질화에 관한 연구)

  • Li-Hoan Kung
    • Journal of the Korean Chemical Society
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    • v.32 no.4
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    • pp.390-405
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    • 1988
  • The chlorination of $C_7H_16,\;C_8H_18,\;C_10H_22,\;and\;(Me_2CH)_2$ with N-Chlorosuccinimide, tert-BuOCl, $CCl_3SO_2Cl,\;CCl_4,\;CCl_3SCl,\; PCl_5,\;and\;Cl_2\;in\;C_6H_6\;or\;CS_2$ which both form loose complexes with $Cl_2$ atoms yielded mixtures of isomeric monochloroalkanes which were analyzed quantitatively. An isomer ratio differing from that known for the substitution of paraffinic hydrocarbons was observed. The isomer distribution observed is the result of the combined effects of the differing C-H dissociation energies of the different types of H atoms of the alkane and of the free energy of the attacking radical with polar effects of the attacking radical as well as of the hydrocarbon.

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