Functionalizable red emitting calcium sensor bearing a 1,4-triazole chelating moiety

Abstract

International audienceHerein we developed a functionalizable OFF-ON red emitting fluorescent calcium probe based on a new chelating system formed by CuAAC click chemistry (Huisgen cycloaddition). The pro-sensor 7 which is not sensitive to Ca2+, contains an alkyne moiety that, upon the click reaction, forms a chelating group involving the 1,4-triazole. Probe 10 exhibited good sensitivity towards calcium (K-d = 5.8 mu M) and zinc (5.6 mu M) with a high dynamic range (65 fold fluorescence increase), high quantum yield (0.59) and showed very low fluorescence enhancement in the presence of a high concentration of Mg2+. We extended this method and generated two dextran conjugates in order to compare their sensing properties with those of the molecular form of 10

Design and Applications of Small Molecular Probes for Calcium Detection

“…Mallet and co-workersr eported ac alcium binding probe 24 where 1,4-triazole ring alongw ith carboxylic acid groups has been used as aC a 2 + -binding unit (Figure 9). [22] The reported probe showed a6 5-fold fluorescencei ncrease with Ca 2 + ions and the dissociation constantf or the Ca 2 + -binding was 5.8 mm.…”

“…Further, 23 in combination with a Na + sensitive probe (ANa1) was employed in living cells/tissues to monitor near membrane Ca 2+ and cytosolic Na + ions. Mallet and co‐workers reported a calcium binding probe 24 where 1,4‐triazole ring along with carboxylic acid groups has been used as a Ca 2+ ‐binding unit (Figure ) . The reported probe showed a 65‐fold fluorescence increase with Ca 2+ ions and the dissociation constant for the Ca 2+ ‐binding was 5.8 μ m .…”

“…Although, APTRA has been employed for the Ca 2+ binding in some instances, however, it has a higher binding affinity for Mg 2+ than Ca 2+ ions. In addition to these binding units, few more carboxylate based units, MOBHA that is, (2‐(2′‐morpholino‐2′‐oxoethoxy)‐ N , N ‐bis(hydroxycarbonyl methyl) aniline) and 1,4‐triazole containing binding unit were also developed (Scheme ).…”

Divergent Palladium‐ and Platinum‐Catalyzed Intramolecular Hydroamination/Hydroarylation of O‐Propargyl‐2‐aminophenols

“…Preparative separations were performed by flash chromatography by using Merck silica gel 0.035–0.070 mm. Compounds 1a , 1b – d, h , 1g were prepared as previously reported.…”

H-Rubies, a new family of red emitting fluorescent pH sensors for living cells

“…Although many uorescent indicators have already been developed (for an extensive review see: Han and Burgess), 12 several factors have to be taken into account in order to achieve efficient use within cells, including solubility in biological media, hydrophobicity, photostability and brightness. Our recent efforts to develop functionalisable red emitting uorescent sensors [13][14][15] were driven by the increasing use of cells transfected with green or yellow uorescent proteins (FPs), thus allowing multicolour imaging. Whilst recent progresses have been reported in the development of red emitting genetically encoded pH sensors, 16 there is still a demand for efficient molecular red uorescent indicators.…”