Quaternary Salts of Halogenated Pyridines and Quinolines<sup>1</sup>

Bahner, Carl Tabb; Easley, Wm. K.; Pickens, Madge D.; Lyons, Harold; Norton, Lilburn L.; Biggerstaff, George E.

doi:10.1021/ja01151a501

Cited by 9 publications

(2 citation statements)

References 2 publications

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“…Cycloimmonium salts 4 a‐g and 4 i‐n were obtained as bromides while the 4‐cyanopyridinium salt 4 h was obtained as a chloride. 3,5‐Difluoropyridinium 4 a and 3,5‐dichloropyridinium 4 b salts are not yet described in the literature, while the other intermediate salts 4 c‐n have already been reported …”

Section: Resultsmentioning

confidence: 99%

Insights on the Chemical Behavior of Ethyl Cyanoformate: Dipolarophile, Cyano or Ethoxycarbonyl Source

Dascălu

Bîcu

Shova³

et al. 2019

ChemistrySelect

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Imidazo[1,2-a]pyridines (azaindolizines) 1a-k have been designed and easily synthesized by the [3 + 2] cycloaddition reaction between cycloimmonium salts and ethyl cyanoformate used as dipolarophile. The behavior of the latter in cycloaddition reactions has been studied using different pyridinium, (iso)quinolinium or benzimidazolium salts and demonstrated the substrate-dependent reactivity, and the observation in many cases of its reaction as a cyano or an ethoxycarbonyl donor reagent. New chemical platforms have been identified thanks to the different reactivity of ethyl cyanoformate. Final molecules were subjected to a biological evaluation on ESKAPE pathogens (five bacteria: Escherichia coli, Klebsiella pneumoniae (MDR), Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus (MRSA) and two fungi: Cryptococcus neoformans (H99) and Candida albicans). Azaindolizines 1b and 1e displayed antifungal activity on Candida albicans and ylide 11 inhibited both fungi Candida albicans and Cryptococcus neoformans. These results open the way for the development of analogues with improved antifungal activity.

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Section: Resultsmentioning

confidence: 99%

Insights on the Chemical Behavior of Ethyl Cyanoformate: Dipolarophile, Cyano or Ethoxycarbonyl Source

Dascălu

Bîcu

Shova³

et al. 2019

ChemistrySelect

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“…The percentage of rounded cells was determined from the images using ImageJ (NIH, Bethesda, MD, USA). Chloroquine and quinacrine were obtained from Sigma Aldrich (Munich, Germany) and were dissolved in H 2 O. HA1383, HA1495, and HA1568 were synthesized as described before [32,[51][52][53][54][55].…”

Section: Cell Culture and Intoxication Experimentsmentioning

confidence: 99%

Characterization and Pharmacological Inhibition of the Pore-Forming Clostridioides difficile CDTb Toxin

Ernst

Landenberger

Nieland

et al. 2021

Toxins

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The clinically highly relevant Clostridioides (C.) difficile releases several AB-type toxins that cause diseases such as diarrhea and pseudomembranous colitis. In addition to the main virulence factors Rho/Ras-glycosylating toxins TcdA and TcdB, hypervirulent strains produce the binary AB-type toxin CDT. CDT consists of two separate proteins. The binding/translocation B-component CDTb facilitates uptake and translocation of the enzyme A-component CDTa to the cytosol of cells. Here, CDTa ADP-ribosylates G-actin, resulting in depolymerization of the actin cytoskeleton. We previously showed that CDTb exhibits cytotoxicity in the absence of CDTa, which is most likely due to pore formation in the cytoplasmic membrane. Here, we further investigated this cytotoxic effect and showed that CDTb impairs CaCo-2 cell viability and leads to redistribution of F-actin without affecting tubulin structures. CDTb was detected at the cytoplasmic membrane in addition to its endosomal localization if CDTb was applied alone. Chloroquine and several of its derivatives, which were previously identified as toxin pore blockers, inhibited intoxication of Vero, HCT116, and CaCo-2 cells by CDTb and CDTb pores in vitro. These results further strengthen pore formation by CDTb in the cytoplasmic membrane as the underlying cytotoxic mechanism and identify pharmacological pore blockers as potent inhibitors of cytotoxicity induced by CDTb and CDTa plus CDTb.

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Halopyridines

Mertal

1961

Chemistry of Heterocyclic Compounds: A Series of Monographs

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It is hoped that the organization of this monograph will prove to be selfexplanatory, but a few general observations are in order.Chemical compounds are tabulated exhaustively by the principle of latest position. Thus halogenated pyridinecarboxylic acids are found in Chapter X rather than VI, but hydroxy acids in Chapter XII. The principal exceptions are the quaternary compounds, which proved too numerous to be catalogued, and the N-oxides, which are included in Chapter IV irrespective of nuclear substitution. Other exceptions are explained where they occur.The principle of latest position does not apply to reactions. All reactions for obtaining pyridine derivatives from non-pyridinoid starting materials are covered in Chapter I1 irrespective of substitution. If the starting material is a pyridine derivative, the reaction is discussed instead in the appropriate later chapter or chapters. Thus the conversion of aminopyridines to pyridinols is discussed in Chapters IX and XII.Nomenclature follows Chemical Abstracts.The editor wishes to express his gratitude to Prof. D. S . Tarbell of the University of Rochester for the impetus he gave to this undertaking, to the chemists in many parts of the world who have been so generous with reprints, to the staff of Interscience Publishers for their cooperation, and finally to Dr. R. S. Long and Dr. J. J. Leavitt of American Cyanamid for their patience. ERWINKLINCSBERG vii Contents of Other Parts Part One I. Properties and Reactions of Pyridine and Its Hydrogenated Derivatives. By 11. Synthetic and Natural Sources of the Pyridine Ring.

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Quaternary Salts of Halogenated Pyridines and Quinolines¹

Cited by 9 publications

References 2 publications

Insights on the Chemical Behavior of Ethyl Cyanoformate: Dipolarophile, Cyano or Ethoxycarbonyl Source

Insights on the Chemical Behavior of Ethyl Cyanoformate: Dipolarophile, Cyano or Ethoxycarbonyl Source

Characterization and Pharmacological Inhibition of the Pore-Forming Clostridioides difficile CDTb Toxin

Halopyridines

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Quaternary Salts of Halogenated Pyridines and Quinolines1

Cited by 9 publications

References 2 publications

Insights on the Chemical Behavior of Ethyl Cyanoformate: Dipolarophile, Cyano or Ethoxycarbonyl Source

Insights on the Chemical Behavior of Ethyl Cyanoformate: Dipolarophile, Cyano or Ethoxycarbonyl Source

Characterization and Pharmacological Inhibition of the Pore-Forming Clostridioides difficile CDTb Toxin

Halopyridines

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Product

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Quaternary Salts of Halogenated Pyridines and Quinolines¹