• 제목/요약/키워드: Ligand oxidation

검색결과 65건 처리시간 0.019초

Effects of Galhwahyejung-tang (GHT) on Protection for Alcohol-induced Liver Injury

  • Ahn Tae-Kyu;Shin Jang-Woo;Cho Chong-Kwan;Cho Jung-Hyo;Yoo Hwa-Seung;Lee Yeon-Weol;Lee Nam-heon;Yun Dam-hee;Son Chang-Gue
    • 대한한의학회지
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    • 제26권1호
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    • pp.76-84
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    • 2005
  • Objective: The purpose of this study was to examine the protective efficacy of GHT on alcoholic liver injury. Methods: We measured the rate of alcohol oxidation, serum level of liver enzyme, lipid peroxidation level in liver tissue, and inflammatory related cytokine expressions in the liver. Results : GHT showed liver protective effects, lowered the levels of AST and LDH in serum and inhibited lipid peroxidation in liver tissue, and enhanced alcohol oxidation. GHT treatment up-regulated IL-10 in the liver, whereas it down­regulated $TNF-\alpha,\;TGF-\beta$, and Fas ligand. Conclusion : From these results, GHT is presumed to work in the liver in protective roles not through the pathway of alcohol metabolism but mainly by anti-inflammation activity in our model.

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단핵 및 이핵성 시프염기리간드 Cu(II) 착물의 특성과 Ascorbic Acid에 대한 산화반응 (Properties of Mononuclear and Binuclear Cu(II) Schiff Base Complexes and Oxidation of Ascorbic Acid)

  • 김선덕;이영석;박정은
    • 분석과학
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    • 제13권5호
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    • pp.558-564
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    • 2000
  • 단핵성 네자리 시프염기인 N,N'-bissalicylidene-1,2-phenylenediamine(BSPD)와 이핵성 네자리 시프 염기 리간드인 N,N',N'',N'''-tetrasalicylidene-3,3',4,4'-tetraaminodiphenyl-methane (TSTM) 및 N, N',N'',N'''-tetrasalicylidene-3,3'-diaminobenzidine (TSDB)을 합성하고, 이들 리간드의 양성자 해리상수를 전위차법으로 구하였다. 합성된 시프염기 리간드들과 Cu(II) 이온을 이용해 착물을 합성하여 순환전압-전류법으로 착물의 특성을 측정한 결과 $Cu(II)_2$-TSTM 착물은 순환전압-전류법에서 두 과정 두 단계의 환원과정으로 두 전자의 확산 지배적인 과정으로 일어남을 알았다. 또한 단핵성 착물 Cu(II)-BSPD와 이핵성 착물 $Cu(II)_2$-TSDB 및 $Cu(II)_2$-TSTM을 ascorbic acid의 산화반응에 이용한 결과, 반응속도는 $Cu(II)_2$ -TSTM>$Cu(II)_2$-TSDB>Cu(II)-BSPD의 순으로 이핵성인 $Cu(II)_2$-TSTM 착물이 가장 큰 값을 가짐을 알았다.

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Manipulation of Absorption Maxima by Controlling Oxidation Potentials in Bis(tridentate) Ru(II) N-Heterocyclic Carbene Complexes

  • Kim, Hyeong-Mook;Jeong, Daero;Noh, Hee Chang;Kang, Youn K.;Chung, Young Keun
    • Bulletin of the Korean Chemical Society
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    • 제35권2호
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    • pp.448-456
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    • 2014
  • A series of seven Ru(II) complexes bearing NHC ligands have been synthesized. The electronic structures of these complexes were analysed by spectroscopic and electrochemical methods and further examined by theoretical calculations. Data show that absorption maxima are dependent on the HOMO level rather than the HOMO-LUMO gaps.

Synthesis and Surface Derivatization of Processible Co Nanoparticles

  • Lee, Jin-Kyu;Choi, Sung-Moon
    • Bulletin of the Korean Chemical Society
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    • 제24권1호
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    • pp.32-36
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    • 2003
  • Co nanoparticles were prepared by the reverse micelle technique (NaBH₄reduction of cobalt chloride in a reversed micelle solution of didodecyldimethylammoniumbromide (DDAB)/toluene). The size and the shape of Co nanoparticles could be easily controlled by changing the water contents and micelle concentrations, and the solubility of Co nanoparticles was systematically tuned by choosing appropriate surface capping organic ligand molecules. Furthermore, a novel nanofabrication process was clearly demonstrated, which generated oxide over-coated Co nanorods from Co nanoparticles in organic solution by slow oxidation with an external magnetic field.

N-Alkylatin of Secondary Amines in Nickel(II) Complexes of Polyaza Macrotricyclic Ligands

  • Suh, Paik-Myunghyun;Kim, Myung-Jin;Kim, Hyun-Kyung;Oh, Kye-Young
    • Bulletin of the Korean Chemical Society
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    • 제13권1호
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    • pp.80-83
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    • 1992
  • The secondary nitrogen donors of the Ni(II) complexes of macrotricyclic ligands 8-methyl-1,3,6,8,10,13,15-heptaazatricyclo $[13.1.1.1^{13,15}]$octadecane (A) and 1,3,6,9,11,14-hexaazatricyclo $[12.2.1.1^{6,9}]$octadecane (B) are N-alkylated and the Ni(II) complexes of $N-Me_2A,\;N-Et_2A,\;and\;N-Me_2B$ are obtained. The Ni(II) complexes of $N-Me_2A\;and\;N-Et_2A$ are stable in acidic aqueous solutions while that of $N-Me_2B$ decomposes relatively rapidly. The N-alkylation leads to the decrease in the ligand field strength as well as an anodic shift in both of the oxidation and the reduction potentials of the Ni(II) complexes.

Electrochemical Behaviour of merdional tris(2-pyridinethiolato)Cobalt(Ⅲ) in Dimethylformamide Solution

  • 천정균;Chae, Hee K.;김용태;고용복;정옥상
    • Bulletin of the Korean Chemical Society
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    • 제18권5호
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    • pp.496-500
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    • 1997
  • Electrochemical behavior of mer-tris(2-pyridinethiolato)cobalt(Ⅲ) in dimethylformamide was studied on a platinum electrode by means of cyclic voltammetry, chronoamperometry, and chronocoulometry. It was found that the neutral complex molecule was electroactive between the potential region of 1.0 and - 1.2 V vs. a nonaqueous Ag/Ag+ electrode. The Co(Ⅲ) complex was reversibly reduced to Co(Ⅱ) species by one-electron transfer at about - 1.1 V, followed by an irreversible dissociation reaction. However, the oxidation process at around 0.8 V, was responsible for an irreversible two-electron transfer that occurred at a ligand site.

Synthesis of (Diamine)platinum(II) and (Diamine)platinum(IV) Complexes of Isopropylidenmalonate Ligand and Their Interaction with Guanosine-$5^{\prime}$-Monophosphate

  • 이은주;전무진;손윤수
    • Bulletin of the Korean Chemical Society
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    • 제19권10호
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    • pp.1099-1105
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    • 1998
  • A series of (diamine)isopropylidenmalonatoplatinum(Ⅱ) complexes and the oxidation products, (diamine)Pt (OOC)2C=C(CH3)2(X)2, (diamine=ethylenediamine(en), 1,2-diaminopropan(dap), N-methylethylenediamine(men); X=OH, OCOCH3, OCOCF3), have been prepared, and their interaction with guanosine-5'-monophosphate (5'-GMP) have been examined by means of 1H NMR spectroscopy. The present platinum(Ⅱ) complexes have shown to interact with 5'-GMP through N7 coordination in two concecutive steps in a similar way as with cisplatin, but no interaction between the present platinum(Ⅳ) complexes and 5'-GMP was observed. However, in the presence of ascorbic acid, the platinum(Ⅳ) complexes have been found to interact with 5'-GMP with the reaction rate depending on their reduction rate.

Synthesis of the New 1,2-Dithiolene Metal Complexes[M$(BDDT)_2^-$] (M=Ni, Cu) and Their Electrode Structures

  • 전기원;Robert D. Bereman
    • Bulletin of the Korean Chemical Society
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    • 제17권7호
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    • pp.612-616
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    • 1996
  • The new 1,2-dithiolene, 1,4-butanediyldithioethylene-1,2-dithiolate (BDDT2-), has been isolated. In addition, new monoanionic bis-complexes with nickel and copper have been prepared and characterized. In order to investigate the detailed electronic structure of the metal complexes of the new ligand, BDDT2-, in terms of the oxidation state of the central metal ions, we have carried out molecular orbital (MO) calculations of Ni(BDDT)2-and Cu(BDDT)2- utilizing an Extended Huckel method. Cyclic voltammetry data for both complexes were obtained with a potentiostat. We have also compared these results to the previously synthesized Ni(PDDT)2-, Ni(DDDT)2-,Cu(PDDT)2-, and Cu(DDDT)2-.

Structural, Electrochemical, DNA Binding and Cleavage Properties of Nickel(II) Complex [Ni(H2biim)2(H2O)2]2+ of 2,2'-Biimidazole

  • Jayamani, Arumugam;Thamilarasan, Vijayan;Ganesan, Venketasan;Sengottuvelan, Nallathambi
    • Bulletin of the Korean Chemical Society
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    • 제34권12호
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    • pp.3695-3702
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    • 2013
  • A nickel(II) complex $[Ni(H_2biim)_2(H_2O)_2](ClO_4)_2{\cdot}H_2O$ (1) of biimidazole ligand has been synthesized and characterized (Where $H_2biim$ = 2,2'-biimidazole). The single crystal X-ray diffraction of the complex shows a dimeric structure with six coordinated psudo-octahedral geometry. The cyclic voltammograms of complex exhibited one quasireversible reduction wave ($E_{pc}=-0.61V$) and an irreversible oxidation wave ($E_{pa}=1.28V$) in DMF solution. The interaction of the complex with Calf-Thymus DNA (CT-DNA) has been investigated by absorption and fluorescence spectroscopy. The complex is an avid DNA binder with a binding constant value of $1.03{\times}10^5M^{-1}$. The results suggest that the nickel(II) complex bind to CT-DNA via intercalative mode and can quench the fluorescence intensity of EB bind to CT-DNA with $K_{app}$ value of $3.2{\times}10^5M^{-1}$. The complex also shown efficient oxidative cleavage of supercoiled pBR322 DNA in the presence of hydrogen peroxide as oxidizing agent. The DNA cleavage by complex in presence of quenchers; viz. DMSO, KI, $NaN_3$ and EDTA reveals that hydroxyl radical or singlet oxygen mechanism is involved. The complex showed invitro antimicrobial activity against four bacteria and two fungi. The antimicrobial activity was nearer to that of standard drugs and greater than that of the free ligand.

Bis[(2-pyridyl)methyl]-2-(2-pyridyl)ethylamine 구리(II) 착물의 합성, 성질 및 X-ray 결정구조 (Synthesis, Properties, and X-ray Crystal Structure of Copper(II) Complex with Bis[(2-pyridyl)methyl]-2-(2-pyridyl)ethylamine)

  • 최기영
    • 대한화학회지
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    • 제51권1호
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    • pp.31-35
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    • 2007
  • 트리포달 구리(II) 착물 [Cu(pmea)(H2O)](ClO4)2·H2O (1) (pmea=bis[(2-pyridyl)methyl]-2-(2-pyridyl)-ethylamine)을 합성하고 X-선 회절법으로 구조를 규명하였다. 이 착물은 삼사정계, 공간군 P-1, a = 9.9362(9) A, b = 15.7299(17) A, c = 18.0562(11) A, α = 68.760(8)°, β = 76.331(6)°, γ = 77.092(9)°, V = 2526.2(4) A3, Z = 2로 결정화 되었다. 각각의 구리 원자는 약간 일그러진 사각뿔 구조를 갖는데, 바탕 면은 pmea 리간드에 있는 세 개의 질소원자와 물 분자가 포함되어 있으며 축 방향에는 피리딘 고리의 질소 원자가 포함되어있다. 착물 1의 순환 전압전류 그림은 가역 일-전자 산화 CuIII 및 환원 CuI 과정으로 진행됨을 보여주었다.