• 제목/요약/키워드: ligand

검색결과 2,321건 처리시간 0.029초

An Approach to Isolation of Thromboxane Synthase (TX-SYN) by Ligand Tethered Affinity Techniques

  • Andersen Niels H.;Rhee Jaekeol
    • Bulletin of the Korean Chemical Society
    • /
    • 제13권2호
    • /
    • pp.119-122
    • /
    • 1992
  • The affinity chromatographic technique was applied to the isolation of Thromboxane Synthase, with a variety of imidazolyl alkanoic acids coupled Sepharose 2B including a gel (G in Table 4) which has one free COOH group in the bound affinity ligand. The effect of ligand structure on the "affinity" and "selectivity" for thromboxane synthase isolation is described.

Spectroscopic Properties and Ligand Field Analysis of cis-Dinitrato(1,4,8,11-tetraazacyclotetradecane)chromium(III) Nitrate

  • 최종하
    • Bulletin of the Korean Chemical Society
    • /
    • 제18권8호
    • /
    • pp.819-823
    • /
    • 1997
  • The luminescence and photoexcitation spectra of cis-[Cr(cyclam)(NO3)2]NO3·½ H2O (cyclam=1,4,8,11-tetraazacyclotetradecane) taken at 77 K are reported. The infrared and visible spectra at room-temperature are also measured. The vibrational intervals of the electronic ground state are extracted from the far-infrared and emission spectra. The ten electronic bands due to spin-allowed and spin-forbidden transitions are assigned. With observed transitions, a ligand field analysis has been performed to determine the bonding property of nitrate group in the chromium(Ⅲ) complex. According to the results, it is found that nitrate ligand has weak σ- and π-donor properties toward chromium(Ⅲ).

Submicrosecond dynamics of nucleic acids studied with a long-lifetime metal-ligand complex

  • Kang, Jung-Sook;Son, Woo-Sung;Kostov-Yordan
    • 대한약학회:학술대회논문집
    • /
    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
    • /
    • pp.312.2-312.2
    • /
    • 2002
  • The metal-ligand complex, [Ru(phen)$_2$(dppz)]^{2+}$ (phen = 1.10-phenanthroline, dppz = dipyrido[3.2-a:2', 3'-c]phenazine) (RuPD), was used as a spectroscopic probe for studying nucleic acid dynamics. The RuPD complex displays a long lifetime and a molecular light switch property upon DNA binding due to shielding of its dppz ligand from water. (omitted)

  • PDF

Electronic Spectroscopy and Ligand Field Analysis of $\Lambda$-fac-Tris(L-alaninato)chromium(III)

  • Choi, Jong-Ha
    • Journal of Photoscience
    • /
    • 제3권1호
    • /
    • pp.43-47
    • /
    • 1996
  • The 77 K emission and excitation, and room-temperature UV-visible spectra of $\Lambda$-fac[Cr(L-ala)$_3$] (ala = alanine anion) have been measured. The ten electronic transitions due to spinallowed and spin-forbidden are assigned. With the observed electronic transition energies, ligand field optimizations have been performed to determine the bonding properties of L-alanine anion toward chromium(III). The angular overlap model (AOM) parameters obtained indicate that it is electron-donating ligand which has values of e$_{\sigma}O$, e$_{\pi}O$, and e$_{\sigma}N$ slightly lower than those of glycine anion (gly). It seem that the decrease of the ligand field properties is due to steric effect of extra methyl group and inductive effect of adjacent carbonyl group.

  • PDF

Synthesis, Structure, and Peroxidase Activity of an Octahedral Ru(III) Complex with a Tripodal Tetraamine Ligand

  • Cho, Jang-Hoon;Kim, Kwan-Mook;Noh, Dong-Youn;Lee, Hong-In
    • Bulletin of the Korean Chemical Society
    • /
    • 제32권11호
    • /
    • pp.3904-3908
    • /
    • 2011
  • A new octahedral Ru(III) complex with a tripodal tetraamine ligand, tpea = tris[2-(1-pyrazoyl)ethyl]amine, has been prepared and characterized. The single crystal X-ray crystallographic study of the complex revealed that the complex has a near octahedral geometry with the tetradentate ligand and two chloride ions. Peroxidase activity was examined by observing the oxidation of 2,2'-azinobis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) with hydrogen peroxide in the presence of the complex. Amount of $ABTS^{+{\bullet}}$ generated during the reaction was monitored by UV/VIS and EPR spectroscopies. After the initiation of the peroxidase reaction, $ABTS^{+{\bullet}}$ concentration increases and then decreases after certain time, indicating that both ABTS and $ABTS^{+{\bullet}}$ are the substrates of the peroxidase activity of the Ru(III) complex.

Electronic Spectroscopy and Ligand Field Analysis of mer-Chloro(1,2-ethanediamine)(1,5,9-triazanonane)chromium(III) Tetrachlorzincate(II)

  • Park, Jong-Ha;Park, Yu-Chul;Kim, Hag-Sung
    • Journal of Photoscience
    • /
    • 제7권3호
    • /
    • pp.97-101
    • /
    • 2000
  • The 77 K emission and excitation spectra, and 298 K infrared and absorption spectra of mer-[CrCl(en)(dpt)]ZnCl$_4$(en=1,2-diaminoethane; dpt=1,5,9-triazanonane) have been measured. Ligand field electronic transitions due to spin-allowed and spin-forbidden are assigned. The zero-phonon line in the excitation spectrum splits into two components by 151$cm^{-1}$ /, and large$^2$E$^{g}$ splitting can be reproduced by the modern ligand field theory. It is confirmed that nitrogen atoms of the en and dpt ligands have a strong $\delta$-donor character, but chloride ligand has weak $\delta$-and $\pi$-donor properties toward chromium(III) ion.

  • PDF

Pseudoreceptor: Concept and an Overview

  • Kothandan, Gugan;Madhavan, Thirumurthy;Gadhe, Changdev G.;Cho, Seung Joo
    • 통합자연과학논문집
    • /
    • 제3권3호
    • /
    • pp.162-167
    • /
    • 2010
  • A pseudoreceptor combines structure-based and ligand-based techniques to represent a unifying concept for both receptor mapping and ligand matching. In this molecular modeling approach, there are opportunities to construct the pseudoreceptor models using a set of small molecules. To build a reliable pseudoreceptor model, we need a set of ligand molecules with known affinity (biological activity) to generate 3D bioactive conformation for each of these ligand molecules. Several software packages are available to generate a pseudoreceptor model and this can provide an entry point for structure based drug discovery in cases where receptor structure information is not available. In this review, we presented the concept of pseudoreceptor, as well as discussed about various software packages available to generate a pseudoreceptor model.

혼성 Bivalent Ligand 퀴놀론 유도체의 합성 (Synthesis of Hybrid Bivalent Ligand Quinolone Derivatives)

  • 이상필;임채욱;김동순;임철부
    • 약학회지
    • /
    • 제38권6호
    • /
    • pp.664-672
    • /
    • 1994
  • Eighteen new hybrid bivalent ligand quinolones that contain two different type of pharmacophores in a single molecule were prepared and evaluated for in viかo antibacterial activity. Hybrid bivalent ligands p-nitrobenzyloxycarbonyl quinolones were prepared by the treatment of active esters of succinyl fluoroquinolones with 1,7-disubstituted fluoroquinolone carboxylic acids in DMF. Eighteen final quinolone carboxylic acids were obtained by the reduction of compounds $25{\sim}42$ with hydrogen in the presence of 10% Pd-C. Among these derivatives, compound[56] showed the most potent antibacterial activity against a wide range of microoranisms.

  • PDF

8-Hydroxyquinoline 誘導體에 關한 硏究 (第2報) Fe (II)-7-Nitroso-8-Hydroxyquinoline-5-Sulfonate 에 關하여 (Studies of 8-Hydroxyquinoline Derivatives (Part II) Fe (II)-7-Nitroso-8-Hydroxyquinoline-5-Sulfonate)

  • 이동형
    • 대한화학회지
    • /
    • 제9권1호
    • /
    • pp.41-44
    • /
    • 1965
  • 7-Nitroso-8-hydroxyquinoline-5-sulfonate의 Fe(II)錯鹽의 性質을 700$m{\mu}$, $26^{\circ}C$에서 分光光度法으로 調査하였다. 이 錯鹽은 pH6.0에서 가장 큰 吸光度를 나타내며 熱安定度도 대단히 좋다. Ligand나 Fe(III)의 還元에 使用한 hydroxylamine이 過剩으로 存在할때 에도 錯鹽의 生成에 影響을 주지 않는다. 錯鹽의 組成을 몰比法과 連續變化法으로 調査한 結果, 金屬과 ligand의 몰比는 1:3이였다. 檢量線은 實驗한 濃度範圍內에서 Beer의 法則에 따른다.

  • PDF