Disease relevance of Imidazole Ring Bound At Distal Site

• LY177507 is representative of a series of phenacyl imidazolium compounds that cause marked lowering of blood glucose levels in animal models of noninsulin-dependent diabetes mellitus [1].
• The acute toxicity of the ligand (imidazolium cyclophane gem-diol dichloride) was assessed by intravenous administration to rats, with an LD 50 of 100 mg/kg of rat [2].
• Biological effects of imidazolium ionic liquids with varying chain lengths in acute Vibrio fischeri and WST-1 cell viability assays [3].
• Series A and B imidazolium salts had very good antimicrobial activity against the examined Gram-negative bacteria, Gram-positive bacteria, and fungi [4].
• The ruthenium(III) complex imidazolium trans-imidazoledimethylsulfoxide-tetrachlororuthenate (NAMI-A) was tested on TS/A adenocarcinoma cells to evaluate the relationship between cell uptake, cell cycle arrest and cytotoxicity [5].

High impact information on Imidazole Ring Bound At Distal Site

• Electron density maps also reveal that active-site residue H141 is protonated as the imidazolium cation [6].
• Editing in vitro and UV crosslinking were inhibited by NaCl and vanadyl ribonucleoside complexes and by chemical modification of sulfhydryl, imidazolium, and guanidinium groups on the protein [7].
• Tissue (type II) transglutaminase covalently incorporates itself, fibrinogen, or fibronectin into high molecular weight complexes on the extracellular surface of isolated hepatocytes. Use of 2-[(2-oxopropyl)thio] imidazolium derivatives as cellular transglutaminase inactivators [8].
• Stabilization of glycogen stores and stimulation of glycogen synthesis in hepatocytes by phenacyl imidazolium compounds [1].
• Less stable NHC carbenes can be conveniently obtained from imidazolium salts using the neutral base [Fe(II)Cp(eta(5)-C(6)Me(5)CH(2))] obtained from 1 and air [9].

Biological context of Imidazole Ring Bound At Distal Site

• Abnormal ligand binding and reversible ring hydrogenation in the reaction of imidazolium salts with IrH(5)(PPh(3))(2) [10].
• It is concluded that the mechanism proposed by Aune and Timasheff [Aune, K.C., and Timasheff, S.N.(1971) Biochemistry 10, 1609-1617] for the solution dimerization which involves the electrostatic interaction between the His-57 imidazolium ring and the terminal carboxyl of Tyr-146 is still most consistent with all the experimental observations [11].
• Chemical evidence for the pH-dependent control of ion-pair geometry in cathepsin B. Benzofuroxan as a reactivity probe sensitive to differences in the mutual disposition of the thiolate and imidazolium components of cysteine proteinase catalytic sites [12].
• Studies on high-temperature amination reactions of aromatic chlorides using discrete palladium-N-heterocyclic carbene (NHC) complexes and in situ palladium/imidazolium salt protocols [13].
• With imidazolium compound in excess over inhibited enzyme, the kinetics of reactivation are well behaved for EPMP-inhibited AChE and depend on the nature of the alkyl ether group R [14].

Anatomical context of Imidazole Ring Bound At Distal Site

• Imidazolium trans-imidazoledimethylsulphoxidetrachlororuthenate (NAMI-A) was tested in vitro on the pro-adhesive properties, evaluated as resistance to trypsin treatment, which is a bona fide measure of adhesion strength, of KB and HeLa carcinoma cell lines and on human polymorphonuclear neutrophils (HPMN) [15].
• PURPOSE: The cytotoxicity, intracellular accumulation and DNA adduct formation of the ruthenium complex imidazolium trans-imidazoledimethylsulfoxide tetrachlororuthenate (ImH[ trans-RuCl(4)(DMSO)Im], Nami-A) were compared in vitro with those of cisplatin in four human tumor cell lines: Igrov-1, 2008, MCF-7, and T47D [16].
• PURPOSE: The uptake of NAMI-A (imidazolium trans-imidazoledimethylsulphoxidetetrachlororuthenate) by KB cells in vitro was compared with the effects of this compound on the cell cycle phase distribution of the cells [17].
• The anti-metastatic agent imidazolium trans-imidazoledimethylsulfoxide-tetrachlororuthenate induces endothelial cell apoptosis by inhibiting the mitogen-activated protein kinase/extracellular signal-regulated kinase signaling pathway [18].
• Interaction of imidazolium and pyridinium dioximes with human erythrocyte acetylcholinesterase [19].

Associations of Imidazole Ring Bound At Distal Site with other chemical compounds

• These studies clearly show for the first time that oxidative addition of imidazolium and thiazolium cations is possible, and the results are discussed in terms of the ramifications for catalysis in imidazolium-based ionic liquids with both carbene-based and non-carbene-based complexes [20].
• Depending on the circumstances, three types of kinetic products can be formed: in one, the imidazole metalation site is the normal C2 as expected; in another, the metalation occurs at the abnormal C4 site; and in the third, C4 metalation is accompanied by hydrogenation of the imidazolium ring [10].
• This titration shift is assigned to the ionization of the imidazolium ion of alkylated histidine, confirming that the inhibitor has alkylated histidine-57 [21].
• The Kd for imidazole binding increased from 0.7 mM at pH 6 to 3.0 mM at pH 8 and could be fit to a single proton ionization curve with a pKa of 7.4, demonstrating the preferential binding by the imidazolium ion (pKa = 7.3) [22].
• Upon complexation of imidazolium salt 15 p with R(1) = phenyl, C-H bond activation of the phenyl ring gave rise to iridium(III) complex 17, which was fully characterized by NMR spectroscopy and X-ray structure analysis [23].

Gene context of Imidazole Ring Bound At Distal Site

• Since PAK2 lacks both cationic center Arg residues, ligand carboxylate binding appears to be accomplished though an imidazolium ion of His64, which is located just below the outer surface of the kringle [24].
• When the pyridinium moiety is replaced by an imidazolium ring, no ChAT inhibition was observed [25].
• The mechanism of recognition at the 5-HT1A receptor was shown to be electrostatic, and conducive to a triggering of the receptor response through the change in the electronic structure of the imidazolium recognition site when it interacts with an activating ligand (agonist) [26].
• For subtilisin Carlsberg, the downfield resonance of the imidazolium N delta 1 proton is approximately 18.3 ppm and the D/H fractionation factor is 0.55 +/- 0.04 at pH 5.5 (11 degrees C), and 0.63 +/- 0.04 (5 degrees C) and 0.68 +/- 0.04 at pH 6 (11 degrees C) [27].
• 1. Mutagenesis of His-172, a potential active-site base and a component of a novel Tyr-His-Asp triad in the active site of TMADH, revealed that the pKa of 8.4+/-0.1 for the wild-type enzyme-substrate complex represents ionization of the imidazolium side-chain of His-172 [28].

Analytical, diagnostic and therapeutic context of Imidazole Ring Bound At Distal Site

• The imidazolium salt cross-links, glyoxal-lysine dimer (GOLD) and methylglyoxal-lysine dimer (MOLD), were measured by liquid chromatography/mass spectrometry and were present in lens protein at concentrations of 0 [29].
• Initial hydrogen transfer can take place from the metal to the carbene to give the imidazolium ring hydrogenation product, as shown by isotope labeling; this hydrogen transfer proves reversible on reflux when the abnormal aromatic carbene is obtained as final product [10].
• The titration shift of this signal is assigned to the deprotonation of the imidazolium cation of alkylated histidine-57 in the denatured/autolysed enzyme-inhibitor derivative [30].
• Electrospray ionization mass spectrometry (ESI-MS) is found to gently and efficiently transfer small to large as well as singly to multiply charged [X+]n[A-]m supramolecules of imidazolium ion (X+) ionic liquids to the gas phase, and to reveal "magic numbers" for their most favored assemblies [31].
• Phase behavior of aqueous mixture of imidazolium ionic liquid, 1-dodecyl-3-methylimidazolium bromide, was investigated by means of differential scanning calorimetry and polarized optical microscopy [32].

References