Novel 7‐maleimido‐2(1H)‐quinolones as potential fluorescent sensors for the detection of sulphydryl groups

Abstract

Novel compounds, based on the 2(1H)‐quinolone skeleton, were synthesised and characterised using 1H‐nuclear magnetic resonance (NMR) spectroscopy and chemical ionisation mass spectrometry (CI MS). Their spectroscopic properties, such as absorption and emission spectra and fluorescence quantum yield, were also examined. 7‐maleimido‐4‐methyl‐2(1H)‐quinolone, 7‐maleimido‐3,4‐dimethyl‐2(1H)‐quinolone, 7‐maleimido‐4‐propyl‐2(1H)‐quinolone and 7‐maleimido‐4‐phenyl‐2(1H)‐quinolone were evaluated as potential sensors for the detection of sulphydryl amino acids groups. These new compounds demonstrate a high ‘turn‐on’ fluorescence response and selectivity towards l‐cysteine in the presence of other amino acids and metal cations.

The synthesis and spectroscopic characterisation of 3‐formyl‐2‐quinolones in the presence of biothiols

“…Given the authors continuing interest in the synthesis of fluorescent and colorimetric chemosensors for thiols , the potential application of compounds 3 and 4 as optical sensors for L‐cysteine was investigated. It is believed that these aldehydes have not previously been examined for possible use as fluorescent and colorimetric probes for thiols.…”

“…The current study is a continuation of the authors’ research into 2(1 H )‐quinolone derivatives as chemosensors for the detection of thiols . Spectroscopic studies were carried out under various conditions.…”

Dyes based on the 2(1H)‐quinolone skeleton as potential colorimetric and fluorescent sensors for cyanide anions

“…In our previous paper, the synthesis, spectroscopic characterisation and potential application of dyes derived from 2(1 H )‐quinolone with dicyanoethylene, maleimide and aldehyde moiety as sensors for the biologically important thiols was reported.…”

Characterization of a novel styrylbenzimidazolium‐based dye and its application in the detection of biothiols

“…According to the published literature, compounds containing a maleimide moiety [ 30–32,46,47 ] as an acceptor can react with nucleophiles by Michael addition. Therefore, we proposed a overall thiol‐sensing reaction pathway using compound 5 in which a nucleophile attaches to the probe according to Scheme 2.…”

“…At higher pH values (pH > 8.5), maleimides are used for detection of primary amines. [ 43,44 ] In our previous research, various Michael acceptors were used as recognition sites for thiols, such as maleimide [ 45–47 ] and dicyanoethylene moieties. [ 48,49 ] Continuing on our research in this direction, we present a novel compound based on styrylbenzimidazolium skeleton and containing a maleimide moiety 5 that acts as an efficient sensor for the detection of biothiols.…”