• Title/Summary/Keyword: $\alpha,\beta$-Elimination

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Purification and Characterization of Dermatan Sulfate from Eel Skin. Anguilla japonica

  • Lee, In-Seon;Sakai-Shinobu;Kim, Wan-Seok;Nakamura-Ayako;Imanari-Toshio;Toida-Toshihiko;Kim, Yeong-Shik
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.316.1-316.1
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    • 2002
  • Dermatan sulfate (DS) was isolated from eel skin (Anguilla japonica) bv actinase and endonuclease digeslions followed by ${\beta}$-elimination reaction and DEAE-Sephacel chromatography. DS was a major glycosaminoglycan in eel skin with 88% of the total uronic acid. The content of IdoA2S$\alpha$1longrightarrow4GalNAc4S sequence in eel skin. which is known to be a binding site to heparin cofactor II. was two times higher than that of dermatan sulfate from porcine skin. The anti-lla activity of eel skin dermatan sulfate mediated through heparin cofactor ll(NCL) was 25 units/mg. whereas DS from porcine skin shows 23.2 units/mg. The average molecular weight was determined as 14 kDa by gel chromatography on a TSKgel G3000SWXL column. Based on H1 NMR spectroscopy. we suggest that 3-sulfated and/or 2.3-sulfated ldoA residues are present in the chain.

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Biosynthesis of L-Azetidine-2-Carboxylic Acid In Actinoplanes ferrugineus

  • Lee, Kang-Man
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1986.12a
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    • pp.505.2-506
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    • 1986
  • L-Azetidine-2-carboxylic acid (A-2-C), a four-membered cyclic imino acid has been identified in certain plants, and the microorganism Actinoplanes ferrugineus. The imino acid A-2-C has a physiological significance as an antgaonist of proline during peptide synthesis. The biosynthetic mechanism for the formation of A-2-C has not been studied in any detail. By using various amino acids such as methionine and S-adenosyl-L-methionine labeled with deuterium or carbon-14, the details of the biosynthetic pathway and a possible mechanism for the formation of L-A-2-C in .4. ferrugineus have been unravelled, Both in vivo and in vitro experimental results suggest the biosynthesis of L-A-2-C is mediated by a confactor containing a carbonyl group, probably pyridoxal Phosphate. S-Adenosyl-L-methionine, which seems to be the direct biosynthetic substrate, has undergone a f-displacement by an ${\alpha}$-amino group of the amino acid portion of the substrate S-adenosyl-L-methionine potentially via a vinylglycine intermediate. The overall stereochemical events at the ${\beta}$-carbon of the substrate have been shown to inversion of configuration. The overall stereochemical events at the -position of the sub- strate have also been shown to occur with inversion of configuration. The ${\beta}$, ${\gamma}$-elimination reaction of the substrate seems to follow a cisoidal-type mechanism and the addition portion of the reaction a transoidal-type mechanism . The assignment of the proton NMR of A-2-C has been deduced by apply- ing NOE difference experiments, Gd(III) line-broadening experiments and 2D-NOESY experiments of regio-and stereospecificially deuterated A-2-C's.

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Stage and Tissue Specific Expression of Four TCR Subunits in Olive Flounder (Paralichthys olivaceus)

  • Lee, Young Mee;Lee, Jeong-Ho;Noh, Jae Koo;Kim, Hyun Chul;Park, Choul-Ji;Park, Jong-Won;Hwang, In Joon;Kim, Sung Yeon
    • Development and Reproduction
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    • v.17 no.4
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    • pp.329-335
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    • 2013
  • TCR subunits are members of membrane-bound receptors which allow the fast and efficient elimination of the specific fish pathogens have regulated function in adaptive immunity. Sequence structure of TCR subunits have been reported for various teleosts, but the information of each TCR subunit functional characterization through expression analysis in fish was unknown. In this study, we examined the gene expression of TCR subunits in the early developmental stages and observed transcript levels in various tissues from healthy adult olive flounder by RT-PCR. The mRNA expression of alpha subunit was already detected in the previous hatching step. But the transcripts of another TCR subunit were not observed during embryo development and increased after hatching and maintained until metamorphosis at the same level. It was found that all TCR subunits mRNAs are commonly expressed in the immune-related organ such as spleen, kidney and gill, also weak expressed in fin and eye. TCR alpha and beta subunit were expressed in brain, whereas gamma and delta were not expressed same tissue. The sequence alignment analysis shows that there are more than 80% sequence homology between TCR subunits. Because it has a high similarity of amino acid sequence to expect similar in function, but expression analysis show that will have may functional diversity due to different time and place of expression.

Maillard Reaction Products Formed from D-Glucose-Glycine, System and Their Formation Mechanism (D-Glucose-Glycine 계의 Maillard 반응생성물 및 그 생성기구)

  • KIM Seon-Bong;PARK Yeung-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.19 no.1
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    • pp.45-51
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    • 1986
  • Equimolar aqueous solutions of D-glucose and glycine were heated at $50^{\circ}C\;and\;95^{\circ}C$ at pH 6.7. The headspace volatiles and the ether extracts from the reaction mixture were analyzed by gas chromatography and gas chromatography-mass spectrometry using a fused silica capillary column. The major components formed were identified as diacetyl, three furfurals, two pyrroles, one furanone, two pyranones and two amides. In order to elucidate the formation mechanisms of the amides formed front amino-carbonyl reaction, two model systems were adopted. N-butylacetamide were formed as major components from diacetyl-butylamine ana glyoxal-butylamine systems, respectively. The results obtained suggest that such ${\alpha}-dicarbonyls$ as 3-deoxy-D-erythro-2,3-hexodiulose and diacetyl generated in the amino-carbonyl reaction react with amino compounds, amides then being formed by cleavage of the C-C bond in the ${\alpha}-dicarbonyls$.

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Antioxidative and Anti-proliferative Effects on MCF-7 Human Breast Cancer Cells of Ikiyangyoung-Tang (익기양영탕(益氣養榮湯)의 항산화 및 유방암 세포주 생장 억제 효과에 미치는 영향)

  • Park, Kyung-Mi;Cho, Seong-Hee;Lee, Jin-A
    • The Journal of Korean Obstetrics and Gynecology
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    • v.20 no.1
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    • pp.32-49
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    • 2007
  • Purpose: Breast cancer is the most common disease in Korean women. Despite remarkable improvements in treatment strategies against various cancer during the past 40 years, breast cancer still remains as one of the main causes of cancer mortality among women in the whole world. This study was carried out to investigate antioxidative and anti-proliferative effects on MCF-7 human breast cancer cells of Ikiyangyoung-Tang extract. Methods: We measured a content of polyphenol and flavonoid in the Ikiyangyoung-Tang extract, eliminative ability of DPPH radical, ABTS free radical and hydrogen peroxide, antioxidative effects of linoleic acid, cytotoxicity on MCF-7 human breast cancer cells. MCF-7 cells were cultured in Dulbecco's modified Eagle's medium/F12(DMEM/F12) supplemented with 10 % fetal bovine serum(FBS; Gibco) and antibiotics. Results : The extract of Ikiyangyoung-Tang contains polyphenol of 168.3${\pm}$12.8 ${\mu}$g/mg and flavonoid of 84.3${\pm}$3.4 ${\mu}$g/mg. Above results show profitable abilities of elimination of ${\alpha}$-${\alpha}$-Diphenyl-${\beta}$-picrylhydrazyl(DPPH) radical, ABTS free radical and hydrogen peroxide. Also, the extract of Ikiyangyoung-Tang strongly inhibits the proliferation of MCF-7 cells in a dose ependent manner. And. it has cytotoxicity on NIH3T3 cells. Conclusion : It can be concluded that Ikiyangyoung-Tang extract has an antioxidative effect and antiproliferative effect on MCF-7 human breast cancer cells.

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Synergistic effects of oxytetracycline and tiamulin against swine respiratory bacteria and their pharmacokinetics in the pigs (돼지호흡기세균에 대한 oxytetracycline과 tiamulin의 시험관내 상승작용 및 돼지에서의 약물동태학)

  • Park, Seung-chun;Yun, Hyo-in;Lee, Keun-woo
    • Korean Journal of Veterinary Research
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    • v.42 no.1
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    • pp.45-54
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    • 2002
  • The study was carried out to characterize the pharmacokinetics after intravenous (iv, 20 mg/kg) and oral (p.o. 100 mg/kg) administration as oxytetracycline (OTC) and tiamulin (TIA) mixture in swine and to determine interaction between OTC and TIA against various pig pathogenic bacteria. The antibacterial effects of OTC in combination with TIA in vitro showed synergistic effect against Salmonella typhimurium 1925, Pasteurella multocida Type A, P. multocida Type D, Krebsiella Pneumoniae 2001, K. Pneumoniae 1560, K. Pneumoniae 2208, Haemophillus pleuropneumonia S 2, and H. pleuropneumonia S 5, but against additive effect E. coli K88ab and S. choleraesuis on the basis of fractional inhibitory concentration (FIC) index. On the while, after i.v. and p.o. administration of OTC and TIA mixture, each OTC and TIA concentrations in plasma were fitted to an open two-compartment model. After i.v. administration of OTC-TIA mixture, the mean distribution half-life ($T_{1/2{\alpha}}$) of OTC and TIA in plasma showed 0.29 h and 0.17 h, and the mean elimination half-life ($T_{1/2{\beta}}$) of those was 4.36 h and 6.64 h, respectively. The mean volume of distribution at steady state ($Vd_{ss}$) of OTC and TIA was $0.85{\ell}/kg$ and $2.44{\ell}/kg$, respectively. After oral administration of OTC and TIA mixture, the mean maximal absorption concentrations ($C_{max}$) of OTC and TIA were $0.60{\mu}g/m{\ell}$ at 1.07 h ($T_{max}$) and $1.68{\mu}g/m{\ell}$ at 1.85 h ($T_{max}$), respectively. The mean elimination half-life ($T_{1/2{\beta}}$) of those showed 6.84 h and 6.36 h. In conclusion, we could suggest in this study that the combination of OTC and TIA may be recommended for the antibacterial therapy against polymicrobial infections, and both OTC and TIA showed large distribution to tissues and high $C_{max}$ after p.o. administration.

Inhibitory Effect of Sageretia theezans against the Production of Pro-Inflammatory Mediators through the Inhibition of NF-κB and MAPK, and Activation of Nrf2/HO-1 Signaling Pathways in LPS-Stimulated RAW264.7 cells

  • Kim, Ha Na;Park, Su Bin;Kim, Jeong Dong;Jeong, Hyung Jin;Jeong, Jin Boo
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2018.10a
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    • pp.98-98
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    • 2018
  • In this study, we evaluated the anti-inflammatory effect of extracts of leaves (ST-L) and branches (ST-B) from Sageretia theezans in LPS-stimulated RAW264.7 cells. ST-L and ST-B significantly inhibited the production of the pro-inflammatory mediators such as NO, iNOS, COX-2, $IL-1{\beta}$ and IL-6 in LPS-stimulated RAW264.7 cells. ST-L and ST-B blocked LPS-induced degradation of $I{\kappa}B-{\alpha}$ and nuclear accumulation of p65, which resulted to the inhibition of $NF-{\kappa}B$ activation in RAW264.7 cells. ST-L and ST-B also attenuated the phosphorylation of ERK1/2, p38 and JNK in LPS-stimulated RAW264.7 cells. In addition, ST-L and ST-B increased HO-1 expression in RAW264.7 cells, and the inhibition of HO-1 by ZnPP reduced the inhibitory effect of ST-L and ST-B against LPS-induced NO production in RAW264.7 cells. Inhibition of p38 activation and ROS elimination attenuated HO-1 expression by ST-L and ST-B, and ROS elimination inhibited p38 activation induced by ST-L and ST-B. ST-L and ST-B dramatically induced nuclear accumulation of Nrf2, but this was significantly reversed by the inhibition of p38 activation and ROS elimination. Collectively, our results suggest that ST-L and ST-B exerts potential anti-inflammatory activity by suppressing $NF-{\kappa}B$ and MAPK signaling activation, and activating HO-1 expression through the nuclear accumulation of Nrf2 via ROS-dependent p38 activation. These findings suggest that ST-L and ST-B may have great potential for the development of anti-inflammatory drug to treat acute and chronic inflammatory disorders.

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Pharmacokinetics of oxytetracycline in rabbits after intravenous and intramuscular administrations (토끼에서 oxytetracycline의 정맥 및 근육 투여시의 약물동태학)

  • Kim, Eun-jung;Yun, Hyo-in;Park, Seung-chun;Oh, Tae-kwang;Cho, Chun-hyung
    • Korean Journal of Veterinary Research
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    • v.34 no.2
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    • pp.259-266
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    • 1994
  • The study was carried out to determine the pharmacokinetic parameters after intravenous(iv) and intramuscular(im) administration (10mg/kr) in healthy rabbits. The results obtained through the experiments were summarized as follows: 1. Bioassay (Bacillus cereus 11778) was evaluated very useful for the determination of oxytetracycline(OTC) in the rabbit serum and tissues, with the detection limit of $0.125{\mu}g/ml$. 2. The pharmacokinetic profiles of OTC (10mg/kg, iv) in rabbits were best described with a two compartment open model $(C=29.5e^{-4,3t}{\pm}3.6^{-0.2t})$, whereas that of OTC (10mg/kg, im) showed a one compartment curve fitting. 3. Following iv administration, a rapid distribution phase was predominant [$t_{\frac{1}{2}}({\alpha}):1.43{\pm}0.98hr$ (♂), $0.5{\pm}0.1hr$(♀)], and then more slow elimination phase ensued [$t_{\frac{1}{2}}({\beta}):4.52{\pm}0.76hr$(♂), $7.32{\pm}2.52hr$(♀)]. Other computer generated pharmacokinetic values were as follows:C1 [$67.76{\pm}18.59ml/kg/h$(♂), $76.03{\pm}22.98ml/kg/h$ (♀)] Vd [$257.74{\pm}180.47ml/kg$ (♂), $92.33{\pm}23.62$ (♀)] AUC [$25.6{\pm}4.44mgh/L$ (♂), $39.6{\pm}12.13mgh/l$ (♀)]. There were no statistical significance between both sexes for all the parameters at the confidence level of 95%. 4. After im administaration, the absorption from the injection sites was very rapid [ Ka:$0.18{\pm}0.03h^{-1}$ (♂), $0.24{\pm}0.02h^{-1}$ (♀)] followed by a monoexponential elimination fashion. The time to peak blood level (Tmax) were calculated $1.64{\pm}0.15hr$ and $1.34{\pm}0.24hr$, in the male and female, respectively. The peak levels (Cmax) at the corresponding time were $1.69{\pm}0.23{\mu}g/ml$ (♂) and $2.08{\pm}0.16{\mu}g/ml$ (♀), with no statistical differences (p>0.05).

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Studies on the ${\beta}-Tyrosinase$ -Part 2. On the Synthesis of Halo-tyrosine by ${\beta}-Tyrosinase$- (${\beta}-Tyrosinase$에 관한 연구 -제2보 ${\beta}-Tyrosinase$에 의한 Halogen화(化) Tyrosine의 합성(合成)-)

  • Kim, Chan-Jo;Nagasawa, Toru;Tani, Yoshiki;Yamada, Hideaki
    • Applied Biological Chemistry
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    • v.22 no.4
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    • pp.198-209
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    • 1979
  • L-Tyrosine, 2-chloro-L-tyrosine, 2-bromo-L-tyrosine, and 2-iodo-L-tyrosine were synthesized by ${\beta}-tyrosinase$ obtained from cells of Escherichia intermedia A-21, through the reversal of the ${\alpha},{\beta}-elimination$ reaction, and their molecular structures were analyzed by element analysis, NMR spectroscopy, mass spectrometry and IR spectroscopy. Rates of synthesis and hydrolysis of halogenated tyrosines by ${\beta}-tyrosinase$, inhibition of the enzyme activity by halogenated phenols, and effects of addition of m-bromophenol on the synthesis of 2-bromotyrosine were determined. The results obtained were as follows: 1) In the synthesis of halogenated tyrosines, the yield of 2-chlorotyrosine from m-chlorophenol were approximately 15 per cent, that of 2-bromotyrosine from m-bromophenol 13.8 per cent, and that of 2-iodotyrosine from m-iodophenol 9.8 per cent. 2) Rate of synthesis of halogenated tyrosines by ${\beta}-tyrosinase$ was slower than that of tyrosine and the rates were decreased in the order of chlorine, bromine and iodine, that is, by increasing the atomic radius. Relative rate of 2-chlorotyrosine synthesis was determined to be 28.2, that of 2-bromotyrosine to be 8.13, and that of 2-iodotyrosine to be 0.98, respectively, against 100 of tyrosine. However 3-iodotyrosine was not synthesized by the enzyme. 3) The relative rate of 2-chlorotyrosine hydrolysis by ${\beta}-tyrosinase$ was 70.7, that of 2-bromotyrosine was 39.0, and that of 2-iodotyrosine was 12.6 against 100 of tyrosine, respectively. The rate of hydrolysis appeared to be decreased in the order of chlorine, bromine and iodine, that is, by increasing the atomic radius or by decreasing the electronegativity. But 3-iodotyrosine was not hydrolyzed by the enzyme. 4) The activity of ${\beta}-tyrosinase$ was inhibited by phenol markedly. Of the halogenated phenols, o-, or m-chlorophenol and o-bromophenol gave marked inhibition on the enzyme action, however inhibition by iodophenol was not strong. Plotting by Lineweaver-Burk method, a mixed-type inhibition by m-chlorophenol was observed and its Ki value was found to be $5.46{\times}10^{-4}M$. 5) During the synthesizing reaction of 2-bromotyrosine by the enzyme, sequential addition of substrate which was m-bromophenol with time intervals and in a small amount resulted in better yield of the product. 6) The halogenated tyrosines which were produced by ${\beta}-tyrosinase$ from pyruvate, ammonia and m-halogenated phenols were analysed to determine their molecular structures by element analysis, NMR spectroscopy, mass spectrometry, and IR spectroscopy. The result indicated that they were 2-chloro-L-tyrosine, 2-bromo-L-tyrosine, and 2-iodo-L-tyrosine, respectively.

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Studies on Cysteine desulfhydrase Produced by Bacteria(Part II) Enzymatic Preparation of L-Cysteine Derivatives by Cysteinedesulfhydrase from Aerobacter aerogenes. (Bacteria가 생산하는 Cysteinedesulfhydrase에 관한 연구(제이보) L-Cysteine 유도체의 효소적 합성에 관하여)

  • 최용진;양한철
    • Microbiology and Biotechnology Letters
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    • v.2 no.1
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    • pp.45-50
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    • 1974
  • 1 With cysteinedesulfhydrase (E. C.4.4.1.1.) from Aerobactor aerogenes, an enzyme which catalyzes the stoichiometric conversion of L-cysteine to pyruvate, ammonia and sulfide, reversibility of the degradation of L-cysteine was investigated. It was found that the enzyme also catalized the reverse reaction of $\alpha$, $\beta$-elimination to synthesize L-cysteine derivatives from pyruvate, ammonia and sulfides when large amounts of substrates were added to the reaction mixtures. 2. The synthetic reaction by cysteinedesulfhydrase proceeded linearly with incubation time and enzyme concentrations. The optimal pH for the synthetic reaction was 10.0. 3. The results of the isolation and identification of the products showed that the L-cysteine derivatives synthesized by this enzymatic method were identical with S-methyl-L-cysteine and S-ethyl-L-cysteine respectively.

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