5470-66-6Relevant articles and documents
Large-scale synthesis of a key catalytic reagent for phosphorus protection in building blocks for isopolar phosphonate oligonucleotide preparation
Rejman, Dominik,Erbs, Jiri,Rosenberg, Ivan
, p. 473 - 476 (2000)
A simple procedure for the large-scale synthesis of 4-methoxy-2-pyridinemethanol 1-oxide (5), a key compound in modern triester synthesis of oligonucleotides, employing Buechi R 152 evaporator as a reaction apparatus was elaborated. Two crucial reaction steps, both strongly exothermic, were satisfactorily handled. Our procedure provides a high-purity, light-and heat-stable product in a satisfactory yield.
Stable and rigid DTPA-like paramagnetic tags suitable for in vitro and in situ protein NMR analysis
Chen, Jia-Liang,Zhao, Yu,Gong, Yan-Jun,Pan, Bin-Bin,Wang, Xiao,Su, Xun-Cheng
, p. 77 - 92 (2017/12/15)
Organic synthesis of a ligand with high binding affinities for paramagnetic lanthanide ions is an effective way of generating paramagnetic effects on proteins. These paramagnetic effects manifested in high-resolution NMR spectroscopy are valuable dynamic and structural restraints of proteins and protein–ligand complexes. A paramagnetic tag generally contains a metal chelating moiety and a reactive group for protein modification. Herein we report two new DTPA-like tags, 4PS-PyDTTA and 4PS-6M-PyDTTA that can be site-specifically attached to a protein with a stable thioether bond. Both protein-tag adducts form stable lanthanide complexes, of which the binding affinities and paramagnetic tensors are tunable with respect to the 6-methyl group in pyridine. Paramagnetic relaxation enhancement (PRE) effects of Gd(III) complex on protein-tag adducts were evaluated in comparison with pseudocontact shift (PCS), and the results indicated that both 4PS-PyDTTA and 4PS-6M-PyDTTA tags are rigid and present high-quality PREs that are crucially important in elucidation of the dynamics and interactions of proteins and protein-ligand complexes. We also show that these two tags are suitable for in-situ protein NMR analysis.
ANTIBIOTIC COMPOUNDS
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Page/Page column 175, (2018/03/25)
The present invention relates to antibiotic compounds of formula (I), to compositions containing these compounds and to methods of treating bacterial diseases and infections using the compounds. The compounds find application in the treatment of infection with, and diseases caused by, Gram-positive and/or Gram-negative bacteria, and in particular in the treatment of infection with, and diseases caused by, Neisseria gonorrhoeae.
Single-armed phenylsulfonated pyridine derivative of DOTA is rigid and stable paramagnetic tag in protein analysis
Yang, Feng,Wang, Xiao,Pan, Bin-Bin,Su, Xun-Cheng
, p. 11535 - 11538 (2016/10/03)
Single-armed DOTA-like phenylsulfonated pyridine derivatives are rigid and stable paramagnetic tags for site-specific labeling of proteins. Their reactions with a solvent-exposed protein thiol group generate a stable C-S bond and produce one single paramagnetic species in solution NMR. The generated large paramagnetic effects yield valuable long-range structural restraints for proteins.
Metal-free methylation of a pyridine N-oxide C-H bond by using peroxides
Li, Gang,Yang, Suling,Lv, Bingjie,Han, Qingqing,Ma, Xingxing,Sun, Kai,Wang, Zhiyong,Zhao, Feng,Lv, Yunhe,Wu, Hankui
supporting information, p. 11184 - 11188 (2015/11/27)
Metal-free methylation of a pyridine N-oxide C-H bond was developed using peroxide as a methyl reagent under neat conditions. Pyridine N-oxide derivatives with various groups (e.g., Cl, NO2, and OCH3) were all suitable substrates, and the desired products were obtained in moderate to excellent yields under standard conditions. Moreover, the methylation can be performed with a good yield on the gram-scale experiment. Tentative mechanistic studies show that the methylation is a classical radical process.
Discovery and crystallography of bicyclic arylaminoazines as potent inhibitors of HIV-1 reverse transcriptase
Lee, Won-Gil,Frey, Kathleen M.,Gallardo-Macias, Ricardo,Spasov, Krasimir A.,Chan, Albert H.,Anderson, Karen S.,Jorgensen, William L.
, p. 4824 - 4827 (2015/10/28)
Non-nucleoside inhibitors of HIV-1 reverse transcriptase (HIV-RT) are reported that incorporate a 7-indolizinylamino or 2-naphthylamino substituent on a pyrimidine or 1,3,5-triazine core. The most potent compounds show below 10 nanomolar activity towards wild-type HIV-1 and variants bearing Tyr181Cys and Lys103Asn/Tyr181Cys resistance mutations. The compounds also feature good aqueous solubility. Crystal structures for two complexes enhance the analysis of the structure-activity data.
C-H bond oxidation catalyzed by an imine-based iron complex: A mechanistic insight
Olivo, Giorgio,Nardi, Martina,Vìdal, Diego,Barbieri, Alessia,Lapi, Andrea,Gómez, Laura,Lanzalunga, Osvaldo,Costas, Miquel,Di Stefano, Stefano
, p. 10141 - 10152 (2015/11/16)
A family of imine-based nonheme iron(II) complexes (LX)2Fe(OTf)2 has been prepared, characterized, and employed as C-H oxidation catalysts. Ligands LX (X = 1, 2, 3, and 4) stand for tridentate imine ligands resulting from spontaneous condensation of 2-pycolyl-amine and 4-substituted-2-picolyl aldehydes. Fast and quantitative formation of the complex occurs just upon mixing aldehyde, amine, and Fe(OTf)2 in a 2:2:1 ratio in acetonitrile solution. The solid-state structures of (L1)2Fe(OTf)(ClO4) and (L3)2Fe(OTf)2 are reported, showing a low-spin octahedral iron center, with the ligands arranged in a meridional fashion. 1H NMR analyses indicate that the solid-state structure and spin state is retained in solution. These analyses also show the presence of an amine-imine tautomeric equilibrium. (LX)2Fe(OTf)2 efficiently catalyze the oxidation of alkyl C-H bonds employing H2O2 as a terminal oxidant. Manipulation of the electronic properties of the imine ligand has only a minor impact on efficiency and selectivity of the oxidative process. A mechanistic study is presented, providing evidence that C-H oxidations are metal-based. Reactions occur with stereoretention at the hydroxylated carbon and selectively at tertiary over secondary C-H bonds. Isotopic labeling analyses show that H2O2 is the dominant origin of the oxygen atoms inserted in the oxygenated product. Experimental evidence is provided that reactions involve initial oxidation of the complexes to the ferric state, and it is proposed that a ligand arm dissociates to enable hydrogen peroxide binding and activation. Selectivity patterns and isotopic labeling studies strongly suggest that activation of hydrogen peroxide occurs by heterolytic O-O cleavage, without the assistance of a cis-binding water or alkyl carboxylic acid. The sum of these observations provides sound evidence that controlled activation of H2O2 at (LX)2Fe(OTf)2 differs from that occurring in biomimetic iron catalysts described to date.
Design and synthesis of N-Aryl isothioureas as a novel class of gastric H+/K+-ATPase inhibitors
Ma, Chao,Wu, Anhui,Wu, Yongqi,Ren, Xuhong,Cheng, Maosheng
, p. 891 - 900 (2014/01/06)
To find new H+/K+-ATPase inhibitors for the treatment of peptic ulcer disease, a series of novel N-aryl isothiourea derivatives were synthesized and their structures were identified by 1H NMR and GC-MS. The effects of these compounds on inhibiting gastric acid secretion were evaluated by the guinea pig stomach mucous membrane study with pantoprazole magnesium as a positive control. The results showed that, of the 37 N-aryl isothiourea compounds synthesized, 20 compounds have comparable or stronger gastric acid inhibitory activities than that of pantoprazole magnesium. The quantitative structure-activity relationships (QSARs) of the N-aryl isothiourea compounds were also studied by comparative molecular field analysis (CoMFA) computation, and the model structure that was supposed to give more powerful bioactivities was finally predicted. A series of novel N-aryl isothiourea derivatives were synthesized and evaluated for their effects of inhibiting gastric acid secretion using the guinea pig stomach mucous membrane study with pantoprazole magnesium as a positive control. Compounds 2c, 2e, and 2k have higher bioactivity. The quantitative structure-activity relationships also defined these structural requirements.
Substituent effects on the catalytic activity of bipyrrolidine-based iron complexes
Olivo, Giorgio,Lanzalunga, Osvaldo,Mandolini, Luigi,Di Stefano, Stefano
, p. 11508 - 11512 (2013/12/04)
The catalytic activity and the selectivity of the new bipyrrolidine-based Fe(II) complexes 2·Fe(OTf)2 and 3·Fe(OTf)2 in the oxidation of a series of alkyl and alkenyl hydrocarbons as well as of an aromatic sulfide with H2O2 were tested and compared with the catalytic efficiency of White's parent complex 1·Fe(OTf)2 in order to evaluate the sensitivity of the reaction to electronic effects.
Tuning of the properties of transition-metal bispidine complexes by variation of the basicity of the aromatic donor groups
Comba, Peter,Morgen, Michael,Wadepohl, Hubert
, p. 6481 - 6501 (2013/07/19)
Bispidines (3,7-diazabicyclo[3.3.1]nonanes) as very rigid and highly preorganized ligands find broad application in the field of coordination chemistry, and the redox potentials of their transition-metal complexes are of importance in oxidation reactions by high-valent iron complexes, aziridination catalyzed by copper complexes, and imaging by 64Cu positron emission tomography tracers. Here, we show that the redox potentials and stability constants of the copper(II) complexes of 15 tetradentate bispidines can be varied by substitution of the pyridine rings (variation of the redox potential over ca. 450 mV and of the complex stability over approximately 10 log units). It is also shown that these variations are predictable by the pKa values of the pyridine groups as well as by the Hammett parameters of the substituents, and the density functional theory based energy decomposition analysis also allows one to accurately predict the redox potentials and concomitant complex stability. It is shown that the main contribution emerges from the electrostatic interaction energy, and the partial charges of the pyridine donor groups therefore also correlate with the redox potentials.
