A fluorescein-based probe with high selectivity to cysteine over homocysteine and glutathione

Abstract

A fluorescent probe based on fluorescein displays excellent selectivity and sensitivity for cysteine and its application for bio-imaging is described.

A ratiometric fluorescent probe for cysteine and its application in living cells

“…After the solvent was evaporated under reduced pressure, the crude solid recrystallized from 30 mL ethanol to give product 5 in 85% yield. 13 …”

“…1 H NMR (400 MHz) and 13 C NMR (100 MHz) spectra were acquired on a Bruker Avance 400 spectrometer, with CDCl 3 or DMSO used as a solvent and tetramethylsilane (TMS) as an internal standard. Melting points were determined with an XD-4 digital micro-melting-point apparatus.…”

“…Certainly, many thiol probes are reported based on the inherent nucleophilicity of sulfydryl group which commonly consist in Cys, GSH and homocysteine (Hcy). The different mechanisms such as conjugate addition/cyclization reaction [12][13][14], aldehyde addition [15][16][17], cleavage reaction [18][19][20], and Michael addition [21][22][23][24] and so on [25][26][27][28][29][30] have also been proposed. However, it is seriously hampered to distinguish Cys from Hcy and GSH because of their similar structure.…”

An off–on fluorescent probe based on maleimide for detecting thiols and its application for bioimaging

“…Especially in recent years, Michael addition type probes for thiols have been the focus of increasing attention. A number of excellent Michael acceptors such as maleimide [19][20][21][22][23][24][25], chromene [26][27][28][29][30][31], squaraine [32][33][34], acrylic acid [35][36][37][38], as well as ␣,␤-unsaturated aldehyde [39,40], ketone [41][42][43][44][45], diesters [46,47], malonitrile [48] and nitro compound [49][50][51] have been exploited for the design of thiols fluorescent probes. Although many promising results have been reported for thiols detection in recent years, there is still a need for improving methodology for this purpose.…”

Development of Fluorescent Phycocyanin-Cu2+ Chemosensor for Detection of Homocysteine

“…For example, Cys is a precursor amino acid of GSH, Coenzyme A and taurine, while Hcy is critical in sulfur metabolism and methionine synthesis [2]. GSH, on the other hand, serves many cellular functions, including maintenance of intracellular redox activities, xenobiotic metabolism, and gene regulation [3]. Elevated levels of mercapto biomolecules have been linked to many diseases such as cancers and cardiovascular disease [4], [5].…”