• Title/Summary/Keyword: Sulfoxide

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Expression, subcellular localization, and antioxidant role of mammalian methionine sulfoxide reductases in Saccharomyces cerevisiae

  • Kwak, Geun-Hee;Kim, Jae-Ryong;Kim, Hwa-Young
    • BMB Reports
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    • v.42 no.2
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    • pp.113-118
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    • 2009
  • Despite the growing body of evidence suggesting a role for MsrA in antioxidant defense, little is currently known regarding the function of MsrB in cellular protection against oxidative stress. In this study, we overexpressed the mammalian MsrB and MsrA genes in Saccharomyces cerevisiae and assessed their subcellular localization and antioxidant functions. We found that the mitochondrial MsrB3 protein (MsrB3B) was localized to the cytosol, but not to the mitochondria, of the yeast cells. The mitochondrial MsrB2 protein was detected in the mitochondria and, to a lesser extent, the cytosol of the yeast cells. In this study, we report the first evidence that MsrB3 overexpression in yeast cells protected them against $H_2O_2$-mediated cell death. Additionally, MsrB2 overexpression also provided yeast cells with resistance to oxidative stress, as did MsrA overexpression. Our results show that mammalian MsrB and MsrA proteins perform crucial functions in protection against oxidative stress in lower eukaryotic yeast cells.

A Study on the Rearrangement of 1,3-Oxathiolane Sulfoxides (1,3-옥사티올란술폭시드의 전위에 관한 연구)

  • Wha Suk Lee;Hoh Gyu Han;In Kyu Kim
    • Journal of the Korean Chemical Society
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    • v.33 no.2
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    • pp.238-246
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    • 1989
  • 1,3-Oxathiolane sulfoxide 4 in which the sulfoxide oxygen and the 2-methyl group are on the same face of the oxathiolane ring undergoes a sigmatropic rearrangement to produce a ring expansion product. The structure of this product would be dihydro-1,4-oxathiin 6 or isomeric exo compound 7. This paper describes physical and chemical methods to determine the correct structure of the two alternatives. Thus, $^1HNMR$, UV spectroscopies, and mass spectrometry showed that the product actually obtained had the structure 6. It was also found that from deuteration reactions of the product the compound 7 was initaly formed and then tautomerized to endo compound 6.

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Nucleophilic Substitution Reactions of α-Chloroacetanilides with Pyridines in Dimethyl Sulfoxide

  • Dey, Shuchismita;Adhikary, Keshab Kumar;Kim, Chan-Kyung;Lee, Bon-Su;Lee, Hai-Whang
    • Bulletin of the Korean Chemical Society
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    • v.26 no.5
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    • pp.776-780
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    • 2005
  • The kinetic studies of the reactions of $\alpha$-chloroacetanilides $(YC_6H_4NRC(=O)CH_2Cl;\;R=H\;(4)\;and\;CH_3$ (5)) with pyridines have been carried out in dimethyl sulfoxide at 95 ${^{\circ}C}$. The pyridinolysis rates are faster with 4 than with 5 whereas the aminolysis rates with benzylamines are faster with 5 than with 4. The Brønsted ${\beta}_X$ values are in the range from 0.30 to 0.32 and the cross-interaction constants, $\rho_{XY}$, are small negative values; $\rho_{XY}$ = -0.06 and -0.10 for 4 and 5, respectively. Based on these and other results, the pyridinolyses of $\alpha$-chloroacetanilides are proposed to proceed via a stepwise mechanism with rate-limiting addition of the nucleophile to the carbonyl group to form zwitterionic tetrahedral intermediate ($T^{\pm}$) followed by a bridged type transition state to expel the leaving group.

The Preparation and its Chemical Properties of Palladium Complexes with a series of Cycloamine (Cycloamine 계의 팔라듐 착물의 합성과 그 화학적 성질)

  • Sang-Oh Oh;Duck-Young Chung
    • Journal of the Korean Chemical Society
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    • v.29 no.4
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    • pp.406-413
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    • 1985
  • We synthesized Pd(II) complexes containing sulfoxide and cycloamine series on the basis of the fact that many workers had the foresight to suggest anticancer activites using Pd(II) complexes with sulfur, nitrogen, or nucleic acid relatives as ligands particulary. The identification and characterization of these complexes are followed; content rates of atoms and molecular weights are confirmed by Elemental Analysis and Mass spectra, bonding of metal and ligands by UV-Vis. spectra and NMR spectra, and donor sites of ligands and configuration of complexes by IR spectra. These are yellow crystals, soluble in methanol and chloroform, and insoluble in H2O and the other common organic solvents.

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Synthesis and Tautomerism of Novel Quinoxalines (Part II) (새로운 Quinoxaline류의 합성과 토토머화 현상 (제2보))

  • Ho Sik Kim;Kyung Ok Choi;Woo Sung Lim
    • Journal of the Korean Chemical Society
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    • v.47 no.4
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    • pp.345-353
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    • 2003
  • The reaction of 6-chloro-3-methoxycarbonylmethylene-2-oxo-1,2,3,4-tetrahydroquinoxaline(5) or 3-methoxycarbonylmethylene-6-nitro-2-oxo-1,2,3,4-tetrahydroquinoxaline(6) with hydrazine hydrate gave 3-hydrazinocarbonylmethylene-2-oxo-1,2,3,4-tetrahydroquinoxalines(7, 8). The reaction of compound 7 or 8 with substituted benzaldehydes or heteroaromatic aldehydes afforded quinoxalines(9-14). Compounds showed the tautomerism between the enamine and methylene imine forms, and between the enamine, methylene imine and enaminol forms in dimethyl sulfoxide solution. The tautomer ratios were determined by the 1H NMR.

Antibacterial Effect of Fructose Laurate Synthesized by Candida antarctica B Lipase-Mediated Transesterification

  • Lee, Ki Ppeum;Kim, Hyung Kwoun
    • Journal of Microbiology and Biotechnology
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    • v.26 no.9
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    • pp.1579-1585
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    • 2016
  • Sugar esters are valuable compounds composed of various sugars and fatty acids that can be used as antibacterial agents and emulsifiers in toothpaste and canned foods. For example, fructose fatty acid esters suppress growth of Streptococcus mutans, a typical pathogenic bacterium causing dental caries. In this study, fructose laurate ester was chosen as a target material and was synthesized by a transesterification reaction using Candida antarctica lipase B. We performed a solvent screening experiment and found that a t-butanol/dimethyl sulfoxide mixture was the best solvent to dissolve fructose and methyl laurate. Fructose laurate was synthesized by transesterification of fructose (100 mM) with methyl laurate (30 mM) in t-butanol containing 20% dimethyl sulfoxide. The conversion yield was about 90%, which was calculated based on the quantity of methyl laurate using high-performance liquid chromatography. Fructose monolaurate (Mr 361) was detected in the reaction mixture by high-resolution mass spectrometry. The inhibitory effect of fructose laurate on growth of oral or food spoilage microorganisms, including S. mutans, Bacillus coagulans, and Geobacillus stearothermophilus, was evaluated.

The Effects of Dimethyl-Sulfoxide on the In vitro Maturation and Fertilization of Bovine Oocytes and the Subsequent Development

  • Tsuzuki, Y.;Duran, D.H.;Kuroki, Y.;Uehara, F.;Ashizawa, K.;Fujihara, N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.11 no.3
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    • pp.307-310
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    • 1998
  • The present studies were undertaken to evaluate the effects of a low concentration of dimethyl-sulfoxide (DMSO) on in vitro maturation and development of bovine oocytes fertilized in vitro. Significantly more oocytes reached the metaphase stage of the second meiotic division in TCM-199 supplemented with $50{\mu}M$ DMSO than in the control medium (p < 0.05), and the highest rates of development up to the blastocyst stage were obtained when $50{\mu}M$ DMSO was added to the maturation and culture media (p < 0.05). The avarage of cell numbers of the blastocysts, expanded and hatched blastocysts cultured with $50{\mu}M$ DMSO were 81.7, 125.7 and 129.9 cells, respectively. The proportion of blastocysts with normal chromosome numbers was 90.5%. These results suggest that the addition of $50{\mu}M$ DMSO is beneficial for the maturation of bovine oocytes and production of the blastocysts with high quality.