• Title/Summary/Keyword: radical

Search Result 10,231, Processing Time 0.034 seconds

Peroxynitrite and Hydroxyl Radical Scavenging Activity of Medicinal Plants (약용식물의 Peroxynitrite와 Hydroxyl radical 소거 활성)

  • Min, Oh-Jin;Kim, Min-Suk;Kwak, Byung-Hee;Rhyu, Dong-Young
    • Korean Journal of Plant Resources
    • /
    • v.21 no.4
    • /
    • pp.254-259
    • /
    • 2008
  • The radical scavenging activities of 9 medicinal plants on peroxynitrite ($ONOO^-$) and hydroxyl (${\cdot}OH$) radical were investigated using in vitro system. The water extracts of 9 medicinal plants showed the protective effect against $ONOO^-$ and ${\cdot}OH$ radical. In particular, Akebia quinata, Aster scaber, Cudrania tricuspidata, Diospyros kaki, Eriobotrya japonica, Lycium chinense, Parthenocissus tricuspidata and Polygonum aviculare exhibited $ONOO^-$-scavenging activity by about 50% at the concentration of $10{\mu}g/ml$. Although those $ONOO^-$-scavenging activities were lower than that of penicillamine (94.08${\pm}$3.04%) as a positive control, Eriobotrya japonica (89.87${\pm}$4.57%) was the most potent scavenger of $ONOO^-$ at the concentration of $10{\mu}g/ml$. Also, Diospyros kaki and Urtica angustifolia showed the strong${\cdot}$OH-scavenging activity than thiourea, positive control, at the concentration of lmg/ml. Our results indicate that 9medicinal plants may act as free radical scavengers and reduce damages caused by oxidative stress associated with $ONOO^-$ and${\cdot}$OH radical.

Radical Additions of Arenethiols to Ynamides for the Selective Synthesis of N-[(Z)-2-(Arylsulfanyl)-1-alkenyl]amides

  • Sato, Akinori;Yorimitsu, Hideki;Oshima, Koichiro
    • Bulletin of the Korean Chemical Society
    • /
    • v.31 no.3
    • /
    • pp.570-576
    • /
    • 2010
  • A variety of ynamides undergo highly regio- and stereoselective radical addition of arenethiols with the aid of triethylborane as a radical initiator. The products, N-[(Z)-2-arylsulfanyl-1-alkenyl]amides, can be reduced with triethylsilane in trifluoroacetic acid to yield N-[2-(arylsulfanyl)alkyl]amides.

ON THE TRANSFINITE POWERS OF THE JACOBSON RADICAL OF A DICC RING

  • Albu, Toma;Teply, Mark L.
    • Journal of the Korean Mathematical Society
    • /
    • v.38 no.6
    • /
    • pp.1117-1123
    • /
    • 2001
  • A ring is a DICC ring if every chain of right ideals in-dexed by the integers stabilizes to the left or to the right or to both sides. A counterexample is given to an assertion of karamzadeh and Motamedi that a transfinite power of the Jacobson radical of a right DICC ring is zero. we determine the behavior of the transfinite powers of the Jacobson radical relative to a torsion theory and consequently can obtain their correct behavior in the classical setting.

  • PDF

k-NIL RADICAL IN BCI-ALGEBRAS II

  • Jun, Y.B;Hong, S.M
    • Communications of the Korean Mathematical Society
    • /
    • v.12 no.3
    • /
    • pp.499-505
    • /
    • 1997
  • This paper is a continuation of [3]. We prove that if A is quasi-associative (resp. an implicative) ideal of a BCI-algebra X then the k-nil radical of A is a quasi-associative (resp. an implicative) ideal of X. We also construct the quotient algebra $X/[Z;k]$ of a BCI-algebra X by the k-nhil radical [A;k], and show that if A and B are closed ideals of BCI-algebras X and Y respectively, then

  • PDF

ON THE EXTENSION DIMENSION OF MODULE CATEGORIES

  • Peng, Yeyang;Zhao, Tiwei
    • Journal of the Korean Mathematical Society
    • /
    • v.57 no.6
    • /
    • pp.1389-1406
    • /
    • 2020
  • Let Λ be an Artin algebra and mod Λ the category of finitely generated right Λ-modules. We prove that the radical layer length of Λ is an upper bound for the radical layer length of mod Λ. We give an upper bound for the extension dimension of mod Λ in terms of the injective dimension of a certain class of simple right Λ-modules and the radical layer length of DΛ.

CORESTRICTION MAP ON BRAUER SUBGROUPS

  • CHOI, EUN-MI
    • Communications of the Korean Mathematical Society
    • /
    • v.20 no.1
    • /
    • pp.35-49
    • /
    • 2005
  • For an extension field K of k, a restriction homomorphism on Brauer k-group B(k) maps Brauer k-algebras to Brauer K- algebras by tensor product. A purpose of this work is to study the restriction map that sends radical (Schur) k-algebras to radical (Schur) K-algebras. And we ask an analogous question with respect to corestriction map on Brauer group B(K) that whether the corestriction map sends radical K-algebras to radical k-algebras.

Characterization of the Active Site of Ascorbyl Free Radical Reductase Purified from Pleurotus ostreatus

  • Yu, Seong-Woon;Kang, Sa-Ouk
    • Proceedings of the Korean Biophysical Society Conference
    • /
    • 1998.06a
    • /
    • pp.25-25
    • /
    • 1998
  • Ascorbyl free radical reductase was purified from the white rot fungus, Pleurotus ostreatus. The enzyme contained FMN as a prosthetic group, which was reduced by NADH and reoxidized by ascorbyl free radical. Reduction of ascorbyl free radical by the enzyme was observed by EPR spectroscopy.(omitted)

  • PDF

Radical Ring-Crossover Polymerization of Macrocycles with Radically Exchangeable Dynamic Covalent Bonds

  • Otsuka, Hideyuki;Yamaguchi, Go;Takahara, Atsushi
    • Proceedings of the Polymer Society of Korea Conference
    • /
    • 2006.10a
    • /
    • pp.320-320
    • /
    • 2006
  • The authors report the synthesis and radical ring-crossover polymerization of macrocycles with radically exchangeable dynamic covalent bonds. The macrocyclic compounds with alkoxyamine units were designed and synthesized by condensation from alkoxyamine-based diol and the corresponding acid chlorides in the presence of pyridine under high-dilution condition. The macrocycles can thermally polymerize by intermolecular radical crossover reaction. Furthermore, the poly(alkoxyamine)s depolymerized to the monomers principally by the intramolecular radical exchange process under high-dilution conditions.

  • PDF

ON THE IMAGE OF DERIVATIONS

  • Bae, Jae-Hyeong
    • Journal of applied mathematics & informatics
    • /
    • v.6 no.3
    • /
    • pp.937-942
    • /
    • 1999
  • In this paper we will show that if [G($\chi$),$\chi$] D($\chi$) and [D($\chi$), G($\chi$)] lie in the nil radical of A for all $\chi$$\in$A, then either D or G maps A into the radical where D and G are derivations on a Banach algebra A.