• Title/Summary/Keyword: selenium compounds

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Production of selenium peptide from yeast

  • Kim, Yeong-Ok;Kim, Eun-Gi
    • 한국생물공학회:학술대회논문집
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    • 2002.04a
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    • pp.208-210
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    • 2002
  • Baker's yeast was cultured with $Na_2SeO_3$. Selenium compounds in yeast were extracted and analyzed by size exclusion chromatography. Selenium was broadly distributed in the fraction of protein. For the inhibition test of MMP-l induction, selenium containing compounds was fractioned by ultrafiltration

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Halogenation of Aldehydes and Ketones by Selenium (IV) Oxyhalides Generated in-situ from Selenium Dioxide and Halotrimethylsilanes

  • 이종근;박인수;서종화
    • Bulletin of the Korean Chemical Society
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    • v.16 no.4
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    • pp.349-355
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    • 1995
  • Bromo-and chlorotrimethylsilane react with selenium dioxide in halocarbon solvents and generate selenium oxybromide and oxychloride, respectively. These in-situ generated oxyhalides turned out to be very efficient for selective bromination and chlorination of aldehydes and ketones. Under carefully controlled reaction conditions, second and third introduction of halogens into carbonyl compounds can be greatly suppressed, and high yields of monohalo compounds were obtained. The product ratios of this halogenation reactions can be best explained if the reactions are assumed to involve intermediate β-ketoselenenyl chlorides.

Effects of Heavy Metal Compounds (As, Cr, and Se) on the Development of Drosophila melanogasier (중금속화합물(As, Cr, Se)이 초파리 발생계에 미치는 영향)

  • 김기원;정연태;박승택;김정중
    • The Korean Journal of Zoology
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    • v.30 no.2
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    • pp.99-106
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    • 1987
  • It is the purpose to investigate the physiological toxity and mutagenicity by heavy metal compounds such as potasium dichromate, sodium arsenite and selenium dioxide on the development of Drosophila melanogaster. These chemical compounds were highly toxic at every developmental stage of Drosophila. The relative values of fecundity, viability and developmental time obtained on food media containing 5 different levels of potasium dichromate (500, 600, 700, 800, and 900 ppm), also 5 different levels of sodium arsenite and selenium dioxide (10, 15, 20, 25 and 30 ppm). Resulting in the relative values of fecundity and viability generally decreased, on the contrary developmental time generally reduced as the concentration of chemicals in the food increased. A significant reduction in the fecundity was observed between 800 and 900 ppm (p<0. 01) on the potasium dichromate media, between 15 and 20 ppm (p<0. 05) on the sodium arsenite media, between 20 and 25 ppm (p<0. 02) on the selenium dioxide media. A significant reduction in the viability was observed between 700 and 800 ppm (p<0. 01) on the potasium dioxide media, between 25 and 30 ppm (p<0. 01) on the sodium arsenite media, between 20 and 25 ppm (p<0. 01) on the selenium dioxide media. The developmental time was significantly reduced between 800 and 900 ppm (p<0. 001) on the potasium dioxide media, between 15 and 20 ppm (p<0. 001) on the sodium arsenite media, and between 25 and 30 ppm (p<0. 01) on the selenium dioxide media.

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Substrate Specificity of the Human Flavin-containing Monooxygenase for Organic Selenium Compounds (사람 Flavin-containing Monooxygenase의 셀레니움화합물에 대한 기질 특이성에 관한 연구)

  • Kim, Young-Mi
    • Environmental Analysis Health and Toxicology
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    • v.15 no.4
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    • pp.139-145
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    • 2000
  • The Flavin-containing monooxygenase (FMOs) (EC1.14.13.8) are NADPH-dependent flavoenzymes that catalyze oxidation of soft nucleophilic heteroatom centers in a range of structurally diverse compounds, including foods, drugs, pesticides, and other xenobiotics. In humans, FMO3 is quantitatively a major human liver monooxygenase. In the present study, the baculovirus expression vector system was used to overexpress human FMO3 in insect cells for catalytic studies. Six commercially available organic selenium compounds were examined for substrate activity with microsomes isolated from Spodoptera frugiperda (Sf)9 cells infected with human FMO3 recombinant baculovirus. While none of the aromatic heterocyclic selenides tested showed detectable activity, all dialkyl- and alkylaryl-selenides free from ionic groups catalyzed the NADPH- and O$_2$-dependent oxidation. Kinetic constants demonstrate that (based on Km) dialkyl-and alkylaryl- selenides are better substrates for human FMO3 than analogous nitrogen or sulfur compounds .

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EFFECT OF SELENIUM COMPOUNDS ON CHEMOPREVENTION AND TUMOR INVASION

  • Chung, An-Sik;Uhee Jung;Yoon, Sang-Oh
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.10a
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    • pp.11-12
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    • 2001
  • Selenium is known to have both chemopreventive and therapeutic benefits of cancer. Recent studies have implicated that apoptosis is one of the most plausible mechanism of chemopreventive effects of selenium compounds and tumor invasion is a new factor involved in chemotherapy. In the present study, we demonstrate that Se-methylselenocysteine(MSC), one of the most effective selenium compound sat chemoprevention, induces apoptosis in HL-60 cells and that ROS plays a crucial role in MSC-induced apoptosis.(omitted)

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ANTIMUTAGENIC STUDY OF SELENIUM COMPOUNDS

  • Bronzetti, Giorgio;Leonardo Caltavuturo, Marco Cini;Croce, Clara Della
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.10a
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    • pp.10-10
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    • 2001
  • Selenium is an essential nutritional element for several animal species and human. It has been also seen, that low levels of selenium in the diet can cause many diseases. This metalloid was defined like a "double face" element because it possesses antioxidant, antimutagen, anticarcinogen but also mutagenic and carcinogenic effects. The most important metabolic role of selenium in the animal species is its presence in the Glutathione Peroxidase(GSH-Px). (omitted)

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Regulation of Cumulus Expansion of Porcine Cumulus-Oocyte Complexes in vitro: Involvement of cAMP and Calcium (돼지 난구세포의 분산조절에 관한 연구 : cAMP와 Calcium의 작용)

  • 권혁방;이원교;김남중;김문규;나철호
    • The Korean Journal of Zoology
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    • v.30 no.2
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    • pp.107-116
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    • 1987
  • It is the purpose to investigate the physiological toxity and mutagenicity by heavy metal compounds such as potasium dichromate, sodium arsenite and selenium dioxide on the development of Drosophila melanogaster. These chemical compounds were highly toxic at every developmental stage of Drosophila. The relative values of fecundity, viability and developmental time obtained on food media containing 5 different levels of potasium dichromate (500, 600, 700, 800, and 900 ppm), also 5 different levels of sodium arsenite and selenium dioxide (10, 15, 20, 25 and 30 ppm). Resulting in the relative values of fecundity and viability generally decreased, on the contrary developmental time generally reduced as the concentration of chemicals in the food increased. A significant reduction in the fecundity was observed between 800 and 900 ppm (p<0. 01) on the potasium dichromate media, between 15 and 20 ppm (p<0. 05) on the sodium arsenite media, between 20 and 25 ppm (p<0. 02) on the selenium dioxide media. A significant reduction in the viability was observed between 700 and 800 ppm (p<0. 01) on the potasium dioxide media, between 25 and 30 ppm (p<0. 01) on the sodium arsenite media, between 20 and 25 ppm (p<0. 01) on the selenium dioxide media. The developmental time was significantly reduced between 800 and 900 ppm (p<0. 001) on the potasium dioxide media, between 15 and 20 ppm (p<0. 001) on the sodium arsenite media, and between 25 and 30 ppm (p<0. 01) on the selenium dioxide media.

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ESTIMATION OF THE BEHAVIORS OF SELENIUM IN THE NEAR FIELD OF REPOSITORY

  • Kim, Seung-Soo;Min, Jae-Ho;Baik, Min-Hoon;Kim, Gye-Nam;Choi, Jong-Won
    • Nuclear Engineering and Technology
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    • v.44 no.8
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    • pp.945-952
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    • 2012
  • The sorption of selenium ions onto iron and iron compounds as a disposal container material and its corrosion products, and onto bentonite as a buffer material, was studied to understand the behaviors of selenium in a waste repository. Selenite was sorbed onto commercial magnetite very well in solutions at around pH 9, but silicate hindered their sorption onto both magnetite and ferrite. Unlike commercial magnetite and ferrite, flesh synthesized magnetite, green rust and iron greatly decreased selenium concentration even in a silicate solution. These results might be due to the formation of precipitates, or the sorption of selenide or selenite onto an iron surface at below Eh= -0.2 V. Red-colored Se(cr) was observed on the surface of a reaction bottle containing iron powder added into a selenite solution. Silicate influences on the sorption onto magnetite and iron for selenide are the same as those for selenite. Even though bentonite adsorbed a slight amount of selenite, the sorption cannot be ignored in the waste repository since a very large quantity of bentonite is used.

Hg(0) Removal Using Se(0)-doped Montmorillonite from Selenite(IV)

  • Lee, Joo-Youp;Kim, Yong Jin
    • Bulletin of the Korean Chemical Society
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    • v.34 no.12
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    • pp.3767-3770
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    • 2013
  • Potassium methylselenite ($KSeO_2(OCH_3)$) was reduced to elemental selenium, Se(0), and then doped onto montmorillonite K 10 (MK10) clay to examine the interaction between elemental mercury (Hg(0)) vapor and Se(0) in an effort to understand the possible heterogeneous reaction of Hg(0) vapor and Se(0) solid. The clay was used as a cost-effective support material for uniform dispersion of Se(0). The Se(0)-doped MK10 showed an excellent reaction performance with Hg(0) under an inert nitrogen gas at 70 and $140^{\circ}C$ in our lab-scale fixed-bed system. However, the precursor, $KSeO_2(OCH_3)$-doped MK10 showed a negligible reaction performance with Hg(0), suggesting that the oxidation state of selenium plays a key role in the reaction of Hg(0) vapor and selenium compounds.