• 셀메드
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• 제2권2호
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• pp.20.1-20.5
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• 2012

$Gynura$ $segetum$ (Lour.) Merr. ($Compositae$) is a well recognized medicinal plant in Indonesia and Malaysia. It is believed to have an anticoagulant effect and is used in treating snake-bites, inflammations and other skin afflictions. This study was carried out to evaluate the antimicrobial effects of $Gynura$ $segetum$ leaves extracts and its fractions. The chemical compositions of the active extracts were also determined. The antimicrobial activities of different solvent extracts of leaves of $Gynura$ $segetum$ were evaluated using the agar well-diffusion method. The Minimum Inhibitory Concentration (MIC) of the active subfractions was determined by the tube dilution method. Gas Chromatography-mass spectrometry (GC-MS) analysis was carried out to identify the chemical compositions of the active extracts. The ethyl acetate fraction and its subfraction E4 performed potent antimicrobial activities and fifteen known chemical constituents were identified by GCMS analysis as 4-vinylphenol, 1-tetradecene, phenol, 2,4-bis(1,1-dimethylethyl), 1-hexadecene, E-15-heptadecenal, hexadecanoic acid, 1,2-benzenedicarboxylic acid, dibutyl ester, 1-docosene, octadecanoic acid, 1-eicosene, cyclotetracosane, 1,2-benzenedicarboxylic acid, bis(2-ethylhexyl)ester, butanedioic acid, monomethyl ester, niacin and 4-hydroxy-benzoic acid. The results of this study suggested a connection between the antimicrobial activities and the chemical structures. The plant may be used as a potential source for antimicrobial agents.

• 한국식품위생안전성학회지
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• 제2권4호
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• pp.181-189
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• 1987

한국 토양균 중에서 esterase 저해제를 생산하는 균주인 Streptomyces strain DMC-498을 oatmeal yeast extract 배지에서 3일간 액내 배양하였을 때 최고의 저해작용을 나타내었으며 균사체의 메탄올 추출물로부터 저해제를 분리하였다. linoleic acid가 저해작용이 있음을 확인하였으며 50% 저해작용을 나타내는 linoleic acid의 양은 $0.045\;\mu\textrm{g}/ml$이었다. 활성이 보다 큰 compound A는 분자량이 500 이상이며 산소를 2개이상 함유하고 있는 환상구조의 지방족 화합물로 생각된다. 이것을 상경적 저해작용을 나타내었다. DMC-498 균주가 함유하는 지질의 주성분은 isostearic acid, isostearic acid methyl ester, linoleic acid methyl ester 및 oleic acid methyl ester이었다.

• Applied Biological Chemistry
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• 제50권3호
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• pp.233-237
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• 2007

순무 뿌리로부터 활성 물질을 분리 동정 하기 위하여 80% MeOH 수용액으로 추출하고 이를 여과, 감압 농축하여 MeOH 추출물을 얻었다. 이를 EtOAc분획, n-BuOH분획, $H_{2}O$분획으로 나누었으며, EtOAc분획과 n-BuOH분획에 대해 silica gel 및 ODS column chromatography를 실시하여 5종의 화합물을 분리 정제하였다. $^{1}H-NMR$, $^{13}C-NMR$, DEPT spectrum 및 Mass spectrum 등을 통하여 palmitic acid methyl ester(1), linolenic acid methyl ester(2), linoleic acid methyl ester(3), ${\beta}-sitosterol$(4), daucosterol(5)으로 구조를 결정하였다.

• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2283-2286
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• 2009

A convenient route for the preparation of water soluble polythiophenes is described. Reactions involving highly active zinc metal show unique properties, viz. tolerance of the ester group and regioselectivity to the thiophene ring. Poly [3-(ethyl-n-alkanoate)thiophene-2,5-diyl]s, poly [3-(n-carboxyalkyl)thiophene-2,5-diyl]s, and poly [3-(potassium- n-alkanoate)thiophene-2,5-diyl]s were easily prepared by utilizing highly active zinc.

• Biotechnology and Bioprocess Engineering:BBE
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• 제1권1호
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• pp.46-50
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• 1996

In order to design industrial scale reactors and proceises for multi-phase biocatalytic reactions, it is essential to understand the mechanisms by which such systems operate. To il-lustrate how such mechanisms can be modeled, the hydrolysis of the primary ester groups of triglycerides to produce fatty acids and monoglycerides by lipased (glycerol-ester hydrolase) catalysis has been selected as an example of multiphase biocatalysis. Lipase is specific in its behavior such that it can act only on the hydrolyzed (or emulsified) part of the substrate. This follows because the active center of the enzyme is catalytically active only when the substrate contacts it in its hydrolyzed form. In other words, lipase acts only when it can shuttleback and forth between the emulsion phase and the water phase, presumably within an interphase or boundary layer between these two phases. In industrial applications lipase is employed as a fat splitting enzyme to remove fat stains from fabrics, in making cheese, to flavor milk products, and to degrade fats in waste products. Effective use of lipase in these processes requires a fundamental understanding of its kinetic behavior and interactions with substrates under various environmental conditions. Therefore, this study focuses on modeling and simulating the enzymatic activity of the lipase as a step towards the basic understanding of multi-phase biocatalysis processes.

• 한국식품영양과학회지
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• 제30권5호
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• pp.943-948
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• 2001

마우스 뇌조직에서 지질과산화를 막아주는 것으로 알려진 청겨자채에 대해서 50%MeOH 추출물(2mg/mL)을 사용하여 소 뇌조직의 산화적스트레스를 유발한 ascorbate/Fe$^{3+}$ system에서 항산화 활성을 조사하였다. 청겨자채 추출물의 용매순차추출 후 TBARS 활성을 각각 용매 분획(100)$\mu\textrm{g}$/mL)별로 확인한 결과 각각의 용매 분획 중 n-BiOH 분획 (49%)이 가장 높았고, EtOAc(40%), H$_{2}$O(9%) 및 n-hexane (0%) 순이었다. n-BuOH 분획을 silica gel column chroma-tography를 반복하였으며, CE, TLC를 통해서 sinapic acid와 ferulic acid를 확인하였다. CE를 통하여 그 함량을 정량한 결과, 건조중량(g)당 sinapic acid는 24.3 ppm 이었고 ferulic acid는 42.8 ppm으로 나타났다. 최종 정제활성물질을 $^{1}$J-NMR(CDCL$_{3}$)와 $^{13}$C-NMR(CDCL$_{3}$)로 확인하였으며 sinapic acid methyl ester, ferulic acid acid와 ferulic acid와 RF치가 일치하는지 여부를 TLC상에서 비교하였다. 동일한 50$\mu\textrm{g}$/mL 농도에서 sinapic acid methyl ester는 40%, ferulic acid methyl ester 는 35%의 항산화 활성을 나타내었으며 이것은 시판되는 표준물질은 sinapic acid(22%)와 ferulic acid (18%)에 비해 약간 높게 나타났다. 이것은이 화합물에 라디칼을 소거하는 작용기와 관계가 있는 것으로 여겨진다. 청겨자채 추출물 중에도 항산화 활성이 비교적 널리 분포된 것으로 보아 이 성분들은 체내에서 단독으로 또는 상호작용으로 항산화 작용을 나타낼 것으로 예상된다.

• 생약학회지
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• 제26권2호
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• pp.130-138
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• 1995

Phytochemical study on the aerial parts of Solanum lyratum (Solanaceae) was carried out. On the basis of phytochemical and spectroscopic evidences, compound I was identified as mixtures of hexadecanoic acid methyl ester, 2,6,10,15-tetramethyl heptadecane, tricosane, tetracosane, pentacosane, docosanoic acid methyl ester, docosane, tricosanoic acid methyl ester, 8-hexyl pentadecane, tetracosanoic acid methyl ester, pentatriacontane, hexatriacontane, eicosane, hexacosane, hentriacontane and stigmasta-5,23-dien $3-{\beta}-ol$, and compound II, III, IV and V were identified as hexacosanoic acid methyl ester, ${\beta}-sitosterol-{\beta}-{_D}-glucoside$, $3-O-{\alpha}-{_L}-rhamnopyranosyl-(1->2)-{\beta}-{_D}-glucuronopyranosyl$ diosgenin and $3-O-{\alpha}-{_L}-rhamnopyranosyl-(1->6)-{\beta}-{_D}-glucopyranosyl$ quercetin (rutin), respectively. Rutin was identified as one of the active principles having antioxidative effect from S. lyratum.

• Bulletin of the Korean Chemical Society
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• 제12권4호
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• pp.376-379
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• 1991

Pyrazolone group containing resin was tested as an acyl carrier in solid phase peptide synthesis. Several kinds of dipeptide derivatives were prepared by aminolysis reactions of Boc-amino acid-pyrazolone resin active ester with various carboxyl protected amino acid derivatives. It was found that the rates of aminolysis reactions were largely dependent on the bulkiness of the amino acid side chains, the carboxyl protecting groups, and the swelling property of the resin. All the dipeptide derivatives were obtained in high yield in 20-30 minutes, and the pyrazolone resin could be reused repeatedly in peptide synthesis without any change of its reactivity.

• Archives of Pharmacal Research
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• 제12권1호
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• pp.58-61
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• 1989

Studies of selectivity of hydrogen bond formation in chiral solute-solvent systems have been performed by $^1H\;and\;^{13}C$ nuclear magnetic resonance techniques. These data are correlated with the results of gas chromatographic investigations of the same systems. Interactions between the optically active solvent(N-(N-benzoyl-L-amino acid)-anilide) and optically active solute (N-trifluoroacetyl -L-alanyl isopropyl ester) were examined. NMR evidence indicated that hydrogen bonding interaction occurred between two N-H portion and on peptidyl carbonyl portion in stationary phase and solute molecule on three points. The association constants of solvent-solute interaction were calculated and the structure of the diastereomeric association complex between N-(N-benzoyl-L-valyl)-anilide and N-TFA-L-alanyl isopropyl ester was proposed.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3318-3326
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• 2010

Five new series of 3,4-ethylenedioxythiophene derivatives carrying important pharamacophores, viz., amide, ester, ether and active secondary aryl moieties have been designed and synthesized through multistep reactions starting from thiodiglycolic ester and diethyl oxalate. They have been characterized by elemental and spectral data. All the target compounds have been screened for their anticonvulsant activity at three different models viz. maximal electroshock (MES), subcutaneous metrazole (scMET), and 6 Hz screen and evaluated for their neurotoxicity in rotorod model. Compound 6a emerged as lead with no neurotoxicity. All the five series of compounds are safe in the toxicity studies at the maximum dose of 300 mg/kg of body weight. Amongst the tested compounds, the ester pharmacophore with thioamide fragment has showed better activity than the other analogs.