1,2,4-Triazolo[4,3-a]quinoxaline-1,4-diones as antiallergic agents
摘要:
A series of new 1,4-dihydro-1,2,4-triazolo[4,3-]quinoxaline-1,4-diones has been prepared. These compounds were tested as inhibitors of antigen-induced release of histamine (AIR) in vitro from rat peritoneal mast cells (RMC) and as inhibitors of IgE-mediated rat passive cutaneous anaphylaxis (PCA). Most of this new class of antiallergic agents showed good activity in the RMC and PCA tests. The most potent compound, 2-acetyl-7-chloro-5-n-propyl-1,2,4-triazolo[4,3-a]quinoxaline-1,4-dione (1x), with an I50 value of 0.1 microM, is 30 times more potent than disodium cromoglycate (DSCG) in the RMC assay.
CO<sub>2</sub> as a C1 Source: B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>-Catalyzed Cyclization of <i>o</i>-Phenylene-diamines To Construct Benzimidazoles in the Presence of Hydrosilane
作者:Zhenbei Zhang、Qiangsheng Sun、Chungu Xia、Wei Sun
DOI:10.1021/acs.orglett.6b03030
日期:2016.12.16
B(C6F5)3-catalyzed synthesis of benzimidazoles via cyclization of o-phenylenediamines with CO2 and PhSiH3. This metal-free catalytic route achieves the desired products in high yield under convenient reaction conditions and is applicable to a broad substrate scope. A plausible mechanism for the reaction involving a frustrated Lewis pair pathway is proposed based on spectroscopic characterization (e.g., 13C NMR) of
使用CO 2作为碳源催化构建苯并咪唑代表了获得这些有价值的化合物的简便且可持续的方法。在这里,我们描述了B(C 6 F 5)3催化的邻苯二胺与CO 2和PhSiH 3的环化反应,合成苯并咪唑。这种无金属的催化途径可以在方便的反应条件下以高收率获得所需的产物,并适用于广泛的底物范围。基于反应中间体的光谱表征(例如13 C NMR),提出了涉及沮丧的路易斯对途径的反应的合理机制。
A Remarkable Oxidative Cascade That Replaces the Riboflavin C8 Methyl with an Amino Group during Roseoflavin Biosynthesis
作者:Isita Jhulki、Prem K. Chanani、Sameh H. Abdelwahed、Tadhg P. Begley
DOI:10.1021/jacs.6b02469
日期:2016.7.13
Roseoflavin is a naturally occurring riboflavin analogue with antibiotic properties. It is biosynthesized from riboflavin in a reaction involving replacement of the C8 methyl with a dimethylamino group. Herein we report the identification of a flavin-dependent enzyme that converts flavin mononucleotide (FMN) and glutamate to 8-amino-FMN via the intermediacy of 8-formyl-FMN. A mechanistic proposal for
[EN] TRIAZOLONE COMPOUNDS AS mPGES-1 INHIBITORS<br/>[FR] COMPOSÉS TRIAZOLONE UTILISÉS COMME INHIBITEURS DE LA MPGES-1
申请人:GLENMARK PHARMACEUTICALS SA
公开号:WO2013186692A1
公开(公告)日:2013-12-19
The present disclosure is directed to compounds of formula (I), and pharmaceutically acceptable salts thereof, as mPGES-1 inhibitors. These compounds are inhibitors of the microsomal prostaglandin E synthase-1 (mPGES-1) enzyme and are therefore useful in the treatment of pain and/or inflammation from a variety of diseases or conditions, such as asthma, osteoarthritis, rheumatoid arthritis, acute or chronic pain and neurodegenerative diseases.
1H,2H,19F,14N ENDOR and TRIPLE resonance investigations of substituted flavin radicals in their different protonation states
作者:E. Weilbacher、N. Helle、M. Elsner、H. Kurreck、F. Müller、R. D. Allendoerfer
DOI:10.1002/mrc.1260260115
日期:1988.1
corresponding radical states. Cation and neutral radicals were generated chemically and anionradicals were obtained electrochemically. By performing ENDOR and TRIPLE resonance experiments, complete sets of hyperfine coupling constants including their signs were accessible. The hyperfine data allowed (a) identification of the radical state present, (b) information to be obtained about the preferred conformational
N,N′-Dialkylation of indolo[2,3-b]quinoxaline could theoretically furnish three isomers, that is, salts dialkylated at the 5,6-, the 6,11-, and the 5,11-positions. By using the 2,3-dimethylated derivatives as models, the regioisomeric salts were selectively synthesized either by alkylation of the tetracycle or by cyclization of 1-methylisatin with N,4,5-trimethylbenzene-1,2-diamine. The structure of