Small molecule probes of the receptor binding site in the Vibrio cholerae CAI-1 quorum sensing circuit
摘要:
Based on modification of separate structural features of the Vibrio cholerae quorum sensing signal, (S)-3-hydroxytridecan-4-one (CAI-1), three focused compound libraries have been synthesized and evaluated for biological activity. Modifications to the acyl tail and alpha-hydroxy ketone typically provided agonists with activities correlated to tail length and conservative changes to the hydroxy ketone. Among the molecules identified within this collection of agonists is Am-CAI-1 (B11), which is among the most potent agonists reported to date with an EC50 of 0.21 mu M. Modifications to the ethyl side chain delivered molecules with both agonist and antagonist activity, including m-OH-Ph-CAI-1 (C13) which is the most potent antagonist reported to date with an IC50 of 36 mu M. The molecules described in this manuscript are anticipated to serve as valuable tools in the study of quorum sensing in Vibrio cholerae and provide new leads in the development of an antivirulence therapy against this human pathogen. (C) 2011 Elsevier Ltd. All rights reserved.
Catalytic α-Deracemization of Ketones Enabled by Photoredox Deprotonation and Enantioselective Protonation
作者:Chenhao Zhang、Anthony Z. Gao、Xin Nie、Chen-Xi Ye、Sergei I. Ivlev、Shuming Chen、Eric Meggers
DOI:10.1021/jacs.1c06637
日期:2021.8.25
deprotonation, followed by enantioselective protonation. The principle of microscopic reversibility, which has previously rendered this strategy elusive, is overcome by a photoredox deprotonation through single electron transfer and subsequent hydrogen atom transfer (HAT). Specifically, the irradiation of racemic pyridylketones in the presence of a single photocatalyst and a tertiary amine provides nonracemic
Asymmetric Imino Aza-enamine Reaction Catalyzed by Axially Chiral Dicarboxylic Acid: Use of Arylaldehyde <i>N</i>,<i>N</i>-Dialkylhydrazones as Acyl Anion Equivalent
作者:Takuya Hashimoto、Maya Hirose、Keiji Maruoka
DOI:10.1021/ja802704j
日期:2008.6.18
Synthetic utility of arylaldehyde N,N-dialkylhydrazones as a practical acyl anion equivalent could be exploited for the first time in the asymmetric imino aza-enamine reaction catalyzed by axiallychiral carboxylic acid.
Small Molecule Suppression of Carbapenem Resistance in NDM-1 Producing <i>Klebsiella pneumoniae</i>
作者:Roberta J. Worthington、Cynthia A. Bunders、Catherine S. Reed、Christian Melander
DOI:10.1021/ml200290p
日期:2012.5.10
The already considerable global public health threat of multidrug-resistant Gram-negative bacteria has become even more of a concern following the emergence of New Delhi metallo-beta-lactamase (NDM-1) producing strains of Klebsiella pneumoniae and other Gram-negative bacteria. As an alternative approach to the traditional development of new bactericidal entities, we have identified a 2-aminoimidazole-derived small molecule that acts as an antibiotic adjuvant and is able to suppress resistance of a NDM-1 producing strain of K. pneumoniae to imipenem and meropenem, in addition to suppressing resistance of other beta-lactam nonsusceptible K. pneumoniae strains. The small molecule is able to lower carbapenem minimum inhibitory concentrations by up to 16-fold, while exhibiting little bactericidal activity itself.