• Title/Summary/Keyword: Amino acid derivatives

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Synthesis of Ketoconazole Derivatives

  • Ryu, Jae-Chun;Lee, Kwang-Jae;Lee, Sang-Hee
    • Bulletin of the Korean Chemical Society
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    • v.24 no.4
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    • pp.460-466
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    • 2003
  • For the drug master file (DMF) of ketoconazole, four impurities (1-4) contained in ketoconazole were synthesized. During the synthesis of 2, a new synthetic method of 1,4-dihydropyrazine was established. To oxidize the aminoalcohol (2j) to the aminal (2j-1), the standard Swern oxidation condition was modified to mask the nucleophilicity of the amino group temporarily using one equivalent of acetic acid. Derivative 3 was synthesized via regioselective bromination at the 2 position of the 4-aminophenol derivative (3a) using $Br_2$ in the presence of p-TsOH. The etherification of aryl bromide with the phenol derivative (1f) was accomplished by a modification of the general Cu-mediated reaction condition using excess 1f itself as a solvent at elevated temperature (190 ℃).

Enhanced thermostability and substrate susceptibility of esteraseusing directed evolution

  • Choe, Gi-Seop;Kim, Ji-Hui;Kim, Geun-Jung;Yu, Yeon-U
    • 한국생물공학회:학술대회논문집
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    • 2003.10a
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    • pp.480-484
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    • 2003
  • A stereoselective-hydrolysing enzyme was cloned from Pseudomonas fluorescens KCTC1767 which had high enantiomeric activity toward (S)-ketoprofen ethyl ester. Analyses of typical properties resulted in low thermostability and substrate specificity. A round error-prone PCR and StEP(STaggered Extension Process) was adopted to evolute this character. As a result, the best clone 6-52 was selected which was represented to increased thermostability(40 fold) compared to wild type enzyme in $50^{\circ}C$. Additionally, specific activity toward (S)-ketoprofen ethyl ester and p-nitrophenyl derivatives improved 3 fold and 1.5 fold, respectively. DNA sequence analyses was showed some exchanged amino acid residue that was L120p, 1208v, T249A, D287H and T357A. Which the 120th's leucine substituted for proline was presumed structurally important residue concerning with catalytic activity.

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Preparation and Characterization of Silk Fibroin Nanoparticles

  • Kweon, Hae-Yong;Yeo, Joo-Hong;Woo, Soon-Ok;Han, Sang-Mi;Jo, You-Young;Lee, Kwang-Gill
    • International Journal of Industrial Entomology and Biomaterials
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    • v.20 no.1
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    • pp.25-28
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    • 2010
  • Silk fibroin was conjugated with methoxypoly(ethylene glycol) derivatives to prepare silk nanoparicles. Conjugation of SF with PEG was examined with various instrumental analyses. Nuclear magnetic resonance spectrometry and amino acid analysis showed that serine and tyrosine residues in SF were reacted with PEG and resulted in increasing molecular weight. The sizes and shapes of SF nanoparticles observed by transmission electronmicroscope were ranged about 150-400 nm in diameter and spherical morphology. UV/VIS spectrometry showed SF nanoparticles might be outer PEG and inner SF structure.

Compositional Sugar Analysis of Antitumor Polysaccharidees by High Performance Liquid Chromatography and Gas Chromatography

  • Kim, Yeong-Shik;Park, Kyung-Shin;Park, Ho-Koon;Kim, Sung-Whan
    • Archives of Pharmacal Research
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    • v.17 no.5
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    • pp.337-342
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    • 1994
  • Carbohydrate analysis is important in studying structure and activity of complex polysaccharides. New analytical method was applied to get an information on the composition of polysaccharides showing antitumor activity. Monosaccharides were labeled with 7-amino-1, 3-naph-thalenedisulfonic acid (7-AGA) by reductive amination and separated by HPLC. Five kinds of polysaccharides from Basidiomycetes were hydrolyzed and analyzed in combination with electrophresis and HPLC. At the same time, alditol acetate derivatives were prepared and analyzed by gas chromatography. Two different techniques using different derivatization methods showed very similar results. The monosaccharides from Coriolus versicolor and Cordyceps militaris were glucose and galactose. Phellinus linteus composed of glucose, glactose, mannose, arabinose and fucose. The HPLC method with fluorescence detector was very sensitive compared to other methods.

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Synthesis of Certain Mercapto and Aminopyrimidine Derivatives as Potential Antimicrobial Agents

  • El-Kerdawy, M.M.;Eisa, H.M.;El-Emam, A.A.;Massoud, M.A.;Nasr, M.N.
    • Archives of Pharmacal Research
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    • v.13 no.2
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    • pp.142-146
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    • 1990
  • Reaction of ethyl 4-chloro-2-phenylpyrimidine-4-carboxylate (4) with 5-chloro-2-methylthiophenol or 3-aryl-4-phenyl-1, 2, 4-triazole-5 thiol yielded the corresponding thioethers (5) and (8a, b), respectively. Careful alkaline hydrolysis of (5) yielded the corresponding carboxylic acid (6). Reaction of (4) with p-aminoacetophenone yielded compound (10) which was reacted with certain aromatic aldehyde to afford the$\alpha,\beta$-unsaturated ketones (11a-d). Condensation of (11a-d) with malononitrile or phenylhydrazine yielded the 2-amino-3-cyanopyridines (12a-f) or the 2-pyrazolines (13a, b) respectively. Seven representative compounds were tested for their in vitro antimicrobial activity against some pathogenic micro-organisms, some of them were proved to be active.

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Activated Nitrites in Heterocyclic Synthesis: Syntheses of Thiazole, Pyrazole and 4H-l,4-Benzothiazine Derivatives

  • El-Taweel, Fathy Mohamed Abdel-Aziz;Hadi-Mashaly, Mohamed-Abdel;Ali-Elagamey, Abdel-Ghani
    • Archives of Pharmacal Research
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    • v.13 no.3
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    • pp.261-264
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    • 1990
  • 4-Arylazo-3-phenyl-5-aminopyrazoles (5a, b) and substituted hydroxythiazoles 8a, b were synthesized from the reaction of 4a, b with hydrazine hydrate and mercaptoacetic acid respectively. Compounds 5a, b and 8a, b were also obtained from coupling of 2a, b with 6 and 7, respectively. 4H-1, 4-Benzothiazine 11 was prepared from 1 and 10. The resaction of the diazonium salts 2a-c with diethyl 3-amino-2-cyanopenet-2-en-1, 5-dicarboxylate 12 was also reported.

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Nitrogen Compounds of Korea ginseng and Their Physiological Significance (고려인삼의 함질소 화합물과 생리학적 중요성)

  • Park, Hoon;Cho, Byung-Goo;Lee, Mee-Kyoung
    • Journal of Ginseng Research
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    • v.14 no.2
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    • pp.317-331
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    • 1990
  • Nitrogen compounds of Panax ginseng and their biological activities in plant and animal were reviewed. Major nitrogen combounds found in P. ginseng are free amino acids, Water soluble teins, insoluble proteins and peptides. Minor nitrogen compounds are dencichine. glycol)roteins. amines, alkaloides, methoxy or alkyl pyrazine derivatives. free nucleosides and nllrleir arid bases. 4-me- thymi-5-thiazoleethanol and pyroglutamic acid. The contents of total nitrogen and protein in root increased until 13 years old rvhich was the highest age tinder investigation. Soluble protein content increased With the root weight and was higher in xylem pith than cortex-epidermis indicating the rlosc relation with root growth. Arginine which covered 58% of total free amino aroids may serve as a storage nitrogen. Arginine seems to be changed into proline in rhizome, threonine in stem and again threoning and arginine in leaf. The greater the root weight the higher the polyaminc content. Polyamine stimulated the growth of root callus. Physiological roles of other minor nitrogen compounds are unknown although dencichine content is relatively high (0.5% d.w.). biochemical and pharmatological activities of some nitrogen compounds for animal were more investigated than physiological roll iota plant itself. Radiation and U.V. protective function (heat stable protein), insulin-like activity in lipogenesis and lipolysis (adenosine and pyroglutamic acid), depression of blood sugar content (glycopeptide). hemostatir and nellrotoxic activity (denrichine) and. sedative and hypnotic activity (4-methyl-5-thiazoleethilnol) are reported. Heat stable protein increased with root age. The traditional quality critsria appear to be well in accordance with biological activities of nitrogen compounds. Chemical stlldies of nitrogen compounds seem relatively rare, probably dole to difficulty of isolation, subsequently the investigations of biological activities are little.

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Changes of Some Physicochemical Properties of Yoghurt made from ${\beta}$-Galactosidase-treated Commercial Milks (${\beta}$-Galactosidase 처리 시유로 제조한 요구르트의 이화학적 성분 변화)

  • Lee, In-Seon;Kim, Sang-Hee;Ha, Jae-Ho;Kang, Kook-Hee
    • Korean Journal of Food Science and Technology
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    • v.21 no.6
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    • pp.795-799
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    • 1989
  • This study was carried out to hydrolyze lactose in commercial milk by ${\beta}-galactosidase$ from Kluyveromyces fragilis and to compare some physicochemical properties of yoghurts made from control and lactase-treated commercial milks. Quantitative analysis of sugars was performed by gas liquid chromatograph (GLC) on trimethylsilyl (TMS) derivatives. In commercial milk, 94.6% of lactose was hydrolyzed after 2 hours incubation at $40^{\circ}C$ with 6.0 units/ml of ${\beta}-galactosidase$. pH, titratable acidity and viable cell number of yoghurt made from lactase-hydrolyzed (LH) commercial milk were 4.1, 1.04% and $6.5{\times}10^8/ml$ of Str. thermophilus, $8.9{\times}10^8/ml$ of L. bulgaricus after 8 hours incubation at $40^{\circ}C$, respectively, The total contents of amino acid were 2.63% in control and 2.19%. in LH yoghurt. The total contents of free amino acid were 26.95 mg% in control and 17.55mg% in LH yoghurt. Analysis of free fatty acids resulted in that the contents of short chain fatty acids in LH yoghurt were a little higher than those in control. Both in control and LH yoghurt, the palmitic acid content was highest and that was followed by oleic and myristic acid.

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Flavor Compounds of Dried Shellfishes 1. Changes of Nitrogenous Compounds in Shellfishes During Drying Process (패류 건제품의 향기성분에 관한 연구 1. 건조가공에 따른 패류의 함질소화합물의 조성변화)

  • JE Yoi-Kwon;KIM Young-Sook;LEE Jong-Ho;JUNG Byung-Chun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.29 no.4
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    • pp.546-555
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    • 1996
  • Level of nitrogenous compounds in dried shellfish related to the formation of flavors during processing and storage was investigated. Fresh samples of blue mussel, short-necked calm and pacific oyster showed relatively low levels of ATP, ADP and AMP, but high levels of iMP and inosine. Relatively high content of TMAO in fresh samples was markedly reduced in the samples broiled samples, but TMA content was rather elevated in the samples broiled, which was a lowered result of TMAO content. The degree of reduction of TMAO and enhancement of TMA contents was relatively small in the hot-air dried samples during storage periods. Glycinebetaine content in fresh samples was slightly decreased by boiling and broiling. Contrast to glycinebetaine content, hormaline and trigonelline contents were severely reduced by boiling and broiling. Twenty-nine kinds of amino acids and their derivatives were identified in the sample of blue mussel, short-necked calm. Among them, glycine, alanine, arginine, glutamic acid and lysine were major amino acids, but contents of these amino acids was greatly decreased in the samples after drying and boiling processes.

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The Effect of Newly Synthesized Compounds on the Photosynthetic Electron Transport of Cyanobacteria (Anacystis nidulans $R_2$) (신규(新規) 합성화합물들이 cyanobacteria의 광합성전자전달계에 미치는 영향)

  • Hwang, I.T.;Kim, J.S.;Cho, K.Y.;Yoneyama, K.;Yoshida, S.
    • Korean Journal of Weed Science
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    • v.13 no.2
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    • pp.89-95
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    • 1993
  • The Inhibiting activity of newly synthesized phenol (E-series) and triazine (T-series) derivatives was evaluated by using thylakoid membranes extracted from cyanobacteria (Anacystis nidulans $R_2$). There were no significant differences between phenol derivatives and dinoseb to the thylakoid membrane extracted from wild type in the Hill reaction. However, a phenol derivative, E-24 which has no -Cl at phenyl ring, did not show any activity. The longer the length of R substituents was in phenol derivatives, the lower inhibiting activity was in the Hill reaction. Triazine derivatives, T-27, T-28, T-40, T-41, T-47 and T-48 were also compared with diuron and atrazine. Among triazine compounds, T-27 and T-28 showed 10 and 30 times activity as high as atrazine to wild type, respectively. Other triazine derivatives, T-40, T-41, T-47 and T-48 showed low inhibiting activity to wild and mutant type. A structural difference of T-27 and T-28 from T-40, T-41, T-47 and T-48 was the presented of -C-NH-. Both T-27 and T-28 were very closely associated with serine, an amino acid located at the 264th position of D1 protein because of the resistant ratio(R/S) to mutant G-264 were higher than that of atrazine.

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