• Title/Summary/Keyword: S/R

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GENTRAL SEPARABLE ALGEBRAS OVER LOCAL-GLOBAL RINGS I

  • Kim, Jae-Gyeom
    • Bulletin of the Korean Mathematical Society
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    • v.30 no.1
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    • pp.61-64
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    • 1993
  • In this paper, we show that if R is a local-global domain then the Question holds. McDonald and Waterhouse in [6] and Estes and Guralnick in [5] introduced the concept of local-global rings (so called rings with many units) independently. A local-global ring is a commutative ring R with 1 satisfying; if a polynomial f in R[ $x_{1}$, .., $x_{n}$] represents a unit over $R_{P}$ for every maximal ideal P in R, then f represents a unit over R. Such rings include semilocal rings, or more generally, rings which are von Neumann regular mod their Jacobson radical, and the ring of all algebraic integers.s.s.

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Analysis of Higher Order Structure of 5S rRNA from Pseudomonas Alcaligenes by using($\eta^{6}$-mesitylene) manganese-(Ⅰ) Tricarbonyl hexafluorophosphate (($\eta^{6}$-Mesitylene) manganese-(Ⅰ) Tricarbonyl hexafluorophosphate를 사용한 Pseudomonas Alcaligenes 5S rRNA의 고차원 구조 분석)

  • Kim, Sang Bumn;Park, In Won
    • Journal of the Korean Chemical Society
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    • v.42 no.2
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    • pp.209-213
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    • 1998
  • The higher order structure of Pseudomonas alcaligenes 5S rRNA has been investigated by using ($\eta^{6}$-mesitylene) manganese (Ⅰ) tricarbonyl hexafluorophosphate[MTH-Mn (Ⅰ)], dimethylpyrocarbonate, potassium permanganate as chemical probes. The sequences cleaved strongly by MTH-Mn (Ⅰ) on the tertiary structure of the 5S rRNA are $G_{12}AUGG_{16}$ of loop a, $G_{51}AAGUGAAGC_{60}$ of the region b-C, $U_{65}-AGCG_{69}$. of the region B-a, and $G_{72}AUGG_{76}$ of loop d. Based on such cleavage patterns of 5S rRNA by MTH-Mn(Ⅰ) and other chemical probes, we presume that the sequences strongly cleaved form pocket-like structure as in the the corner of L structure of $tRNA^{Phe}$. We also presume that the region b-C and loop d together play a role of hinge in forming the pocket-like structure in the 5S rRNA.

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Novel Anthracene Derivatives Isolated from Rice Hulls of Oryza sativa and Their Growth Inhibitory Activity of Radish Seed

  • Jeong, Il-Min;Lim, Yoong-Ho;Ali, Mohd;Sultana, Shahnaz;Ahmad, Ateeque
    • Bulletin of the Korean Chemical Society
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    • v.27 no.7
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    • pp.995-1000
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    • 2006
  • Three new compounds orizaanthracenol (1-methoxyanthracen-2-ol, 1), 1-hydroxy-7-((2S,3R,4R,5S)-2'',3'',4''-trihydroxy-5''-(hydroxymethyl)tetrahydro-2H-pyran-1-yloxy)anthracen- 2-yl 3',7'-dimethyloctanoate (2) and 1-hydroxy-7-((2S,3R,4R,5S)-2'',3'',4''-trihydroxy-5''-(hydroxymethyl)tetrahydro-2H-pyran-1-yloxy)anthracen- 2-yl 3',7',11',15',19'-pentamethyltricosanoate (3) have been isolated and determined from the rice hulls of Oryza sativa. The structures of the compounds were elucidated using 1D and 2D NMR spectral methods, viz: 1H-NMR, 13C-NMR, DEPT, COSY and HSQC, and HMBC aided by IR, EIMS and FAB-MS. These isolated compounds were tested in bioassay on germination of radish to detect their inhibitory activities, in which compound 1 exhibited the most inhibition at the concentration of 40 ppm was 50.96% of total dry weight. Furthermore, germination and growth of radish were reduced by 27 to 48%, and dry weight of shoot and root were arranged from 50 to 52%, whilst compounds 2 and 3 exhibited weak inhibition than 1.