82664-05-9Relevant academic research and scientific papers
Synthesis of Novel D–π–A Dyes for Colorimetric Cyanide Sensing Based on Hemicyanine–Functionalized N-(2-Pyridyl)pyrazoles
Garzón, Luz-Mery,Portilla, Jaime
, p. 7079 - 7088 (2019)
Novel integrated N-(2-pyridyl)pyrazole-hemicyanine dyes (PH) were synthesized as promisor chemodosimeters for colorimetric and ratiometric CN– detection. These dyes, obtained by a three-step sequence starting from acetophenones in up to 69 % overall yield, are donor–π–acceptor (D–π–A) systems consisting of indolium-salts bearing a modular donor aryl group on its pyrazole ring PHa–e. The salts displayed high selectivity and sensitivity for CN– (LOD of up to 9.9 × 10–7 m), as determined by interrupting the modular D–π–A system by nucleophilic attack of the cyanide on its iminium group; the mechanism of this process was confirmed by Job′s plot experiment, spectral analysis, cyclic voltammetry studies and TD-DFT calculations. This probe changes its color from deep yellow to colorless and can be used for in-the-field measurements without special equipment, since this change can be easily observed by the naked eye; indeed, yellow test strips were suitably used to detect CN– in water.
Synthesis and evaluation of analgesic, antiinflammatory and antiplatelet properties of new 2-pyridylarylhydrazone derivatives
Todeschini, Adriane R.,De Miranda, Ana Luisa P.,Da Silva, Kelly Christine M.,Parrini, Sergio C.,Barreiro, Eliezer J.
, p. 189 - 199 (2007/10/03)
This work describes recent results from our research program aiming at the synthesis and pharmacological evaluation of new compounds acting as antiinflammatory, analgesic and platelet antiaggregatory. In this paper the synthesis and the pharmacological profile as analgesic, antiinflammatory and anti-platelet of new functionalized 2-pyridylarylhydrazone derivatives 5a-r are discussed. This class of N-heterocyclic derivatives represents a new series of prototype candidates with analgesic and antiinflammatory properties possessing also an important anti-aggregating activity. The pharmacological results herein disclosed suggest that the anti-inflammatory and analgesic activities of these new pyridynehydrazone derivatives observed in the carrageenan pleurisy model and acetic acid writhing test, respectively, is probably due to an interference on the arachidonic acid (AA) metabolism. The most important antiinflammatory derivative 2-(2-formylfurane)pyridylhydrazone 5p presented a 79% inhibition of pleurisy at a dose of 80.1 μmol/kg. We also described the results concerning the mechanism of action of this series of N-heterocyclic derivatives in platelet aggregation which suggest a Ca2+ participation, probably by a complexation scavenger mechanism. Compound 2-(2-formylfurane)pyridylhydrazone 5p was able to complex Ca2+ in in vitro experiments at 100 μM concentration, indicating that this series of compounds can act as Ca2+ scavenger depending on the nature of the aryl moiety present at the imine subunit.
