Dyes derived from 3‐formyl‐2(1H)‐quinolone – synthesis, spectroscopic characterisation, and their behaviour in the presence of sulfhydryl and non‐sulfhydryl amino acids

Abstract

Novel dyes based on a 3-formyl-2(1H)-quinolone skeleton were synthesised and characterised using 1 H nuclear magnetic resonance spectroscopy and mass spectrometry. The spectroscopic properties of these dyes, such as their absorption spectra, emission spectra, and quantum fluorescence yields, were also examined. The behaviour of the obtained compounds at a pH of 7.4 in the absence and in the presence of thiol amino acids, such as L-cysteine, L-glutathione, and N-acetyl-L-cysteine, were studied. The spectroscopic responses of the tested dyes towards other amino acids were also investigated. A reference compound was synthesised to understand the reaction mechanism between the thiols and the obtained dyes. The experimental results show that the synthesised dyes have the potential to act as sensors for thiols. Coloration TechnologySociety of Dyers and Colourists 157

Synthesis, spectroscopic characterisation, and potential application of dyes containing a carbostyril skeleton as sensors for thiols

“…On the other hand, no changes with time in the absorption spectra of dyes 7 are observed. It is worth mentioning again that similar behaviour of the analogues substituted in the 6‐position, under the same conditions, also occurred, as reported in our earlier paper .…”

“…It is well known from the literature that thiols are capable of addition to the double bonds of unsaturated compounds to give various sulphides . Thus, based on previously reported studies of the reaction mechanism between thiols and a coumarin probe with a dicyanoethylene moiety , and also our previous studies and studies of the reaction mechanism between thiols and a benzoxazine‐hemicyanine probe , during the reaction of dyes 6 and 7 with thiols the product of addition to the double bond is expected to be formed. The proposed reactions between thiols and the obtained dyes are shown in Scheme .…”

“…Acetanilides 1a and 1b , 2‐chloro‐3‐formylquinolines 2a and 2b , as well as 3‐formyl‐2( 1H )‐quinolones 3a and 3b were synthesised according to the procedures described elsewhere : 2a : yield 85%; mp 143 °C (146 °C ). 2b : yield 81%; mp 192 °C (196 °C ). 3a : yield 79%; mp 263 °C (259 °C ). 1 H NMR (250 MHz) in DMSO‐ d 6 : δ 2.39 (s, 3H), 7.06–7.12 (m, 2H), 7.90 (d, J = 8.1 Hz, 1H), 8.44 (s, 1H), 10.20 (s, 1H), 12.15 (bs, 1H). 3b : yield 86%; mp 266 °C (268–269 °C ).…”

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.…”

Dyes derived from benzo[a]phenoxazine – synthesis, spectroscopic properties, and potential application as sensors for l‐cysteine

“…Alterations in the levels of biothiols are connected with some neurodegenerative and cardiovascular diseases [18]. In our previous papers [20,21], the synthesis and spectroscopic characterisation, in the presence of various amino acids, of dyes derived from 3formyl-2(1H)-quinolone with different moieties acting as a Michael acceptor were reported. The optical detection of thiols is based on specific reactions between probes and sulphydryl derivatives.…”