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Abstract We present the synthesis, properties, and imaging applications of a new class of diazaborine‐based probes (Peroxynitrite Probe‐1,PNP‐1) for selective peroxynitrite (ONOO−) imaging in live cells.PNP‐1features a diazaborine‐based reaction motif that provides excellent discrimination between H2O2and ONOO−, solving a persistent challenge of organoboron‐based fluorescent probes for oxidative metabolite imaging. We demonstrate the utility ofPNP‐1to detect endogenously produced ONOO−in live RAW 264.7 macrophages by fluorescence microscopy, with probe selectivity confirmed with inhibition of NADPH oxidases and nitric oxide synthase, the requisite enzymatic machinery for ONOO−production. Co‐localization studies unexpectedly reveal preferential mitochondrial localization, which we show is dependent on the naphthalimide scaffold. Taken together, our results show that diazaborines are a novel motif for selective ONOO−reactivity, positioning them for incorporation into other ONOO−‐specific chemical biology tools.
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Fluorogenic Probe Using a Mislow–Evans Rearrangement for Real‐Time Imaging of Hydrogen Peroxide
Abstract Hydrogen peroxide (H2O2) mediates the biology of wound healing, apoptosis, inflammation, etc. H2O2has been fluorometrically imaged with protein‐ or small‐molecule‐based probes. However, only protein‐based probes have afforded temporal insights within seconds. Small‐molecule‐based electrophilic probes for H2O2require many minutes for a sufficient response in biological systems. Here, we report a fluorogenic probe that selectively undergoes a [2,3]‐sigmatropic rearrangement (seleno‐Mislow‐Evans rearrangement) with H2O2, followed by acetal hydrolysis, to produce a green fluorescent molecule in seconds. Unlike other electrophilic probes, the current probe acts as a nucleophile. The fast kinetics enabled real‐time imaging of H2O2produced in endothelial cells in 8 seconds (much earlier than previously shown) and H2O2in a zebrafish wound healing model. This work may provide a platform for endogenous H2O2detection in real time with chemical probes.
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- PAR ID:
- 10181573
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 59
- Issue:
- 40
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 17435-17441
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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