Mild Chemotriggered Generation of a Fluorophore-Tethered Diazoalkane Species via Smiles Rearrangement

In situ generation of diazoalkanes under mild conditions is desired. A mechanism based on a Smiles rearrangement has been devised that releases a fluorophore-labeled unstabilized diazoalkane in the presence of various chemical triggers. Notably, the release of this diazoalkane is accompanied by an intense fluorescence turn-on, which calibrates the release of the diazoalkane. Carboxylic acids can trap this short-lived diazoalkane intermediate and yield the corresponding esters. This transformation has potential for broad applications

Super-Resolution Monitoring of Mitochondrial Dynamics upon Time-Gated Photo-Triggered Release of Nitric Oxide

Nitric oxide (NO) potentially plays a regulatory role in mitochondrial fusion and fission, which are vital to cell survival and implicated in health, disease, and aging. Molecular tools facilitating the study of the relationship between NO and mitochondrial dynamics are in need. We have recently developed a novel NO donor (<b>NOD550</b>). Upon photoactivation, <b>NOD550</b> decomposes to release two NO molecules and a fluorophore. The NO release could be spatially mapped with subdiffraction resolution and with a temporal resolution of 10 s. Due to the preferential localization of <b>NOD550</b> at mitochondria, morphology and dynamics of mitochondria could be monitored upon NO release from <b>NOD550</b>

A Water-Soluble, Green-Light Triggered, and Photo-Calibrated Nitric Oxide Donor for Biological Applications

Nitric oxide (NO) is a versatile endogenous molecule, involved in various physiological processes and implicated in the progression of many pathological conditions. Therefore, NO donors are valuable tools in NO related basic and applied applications. The traditional spontaneous NO donors are limited in scenarios where flux, localization, and dose of NO could be monitored. This has promoted the development of novel NO donors, whose NO release is not only under control, but also self-calibrated. Herein, we reported a phototriggered and photocalibrated NO donor (<b>NOD565</b>) with an N-nitroso group on a rhodamine dye. <b>NOD565</b> is nonfluorescent and could release NO efficiently upon irradiation by green light. A bright rhodamine dye is generated as a side-product and its fluorescence can be used to monitor the NO release. The potentials of <b>NOD565</b> in practical applications are showcased in in vitro studies, e.g., platelet aggregation inhibition and fungi growth suppression