2-Amino-3'-dialkylaminobiphenyl-based fluorescent intracellular probes for nitric oxide surrogate NO.

Fluorescent probes for nitric oxide (NO), or more frequently for its oxidized surrogate dinitrogen trioxide (NO), have enabled scientists to study the contributions of this signaling molecule to many physiological processes. Seeking to improve upon limitations of other probes, we have developed a family of fluorescent probes based on a 2-amino-3'-dialkylaminobiphenyl core. This core condenses with NO to form benzo[]cinnoline structures, incorporating the analyte into the newly formed fluorophore, which results in product fluorescence with virtually no background contribution from the initial probe.

Understanding the Selectivity of a Multichannel Fluorescent Probe for Peroxynitrite Over Hypochlorite.

Peroxynitrite is a prominent biological reactive nitrogen species from radical combination of nitric oxide and superoxide and fundamentally involved in broad spectrum physiological and pathological processes. Though redox-inert itself, peroxynitrite anion (OONO(-)) attacks various biological electrophiles to generate an array of potent 2-e(-) or 1-e(-) oxidants, which result in cell injuries. Development of fluorescent probes for peroxynitrite, free from interference from hypochlorite, has been an active endeavor of the chemical community.

Practical assay for nitrite and nitrosothiol as an alternative to the Griess assay or the 2,3-diaminonaphthalene assay.

Nitrite is a heavily assayed substrate in the fields of food safety, water quality control, disease diagnosis, and forensic investigation and more recently in basic biological studies on nitric oxide physiology and pathology. The colorimetric Griess assay and the fluorimetric 2,3-diaminonaphthalene (DAN) assay are the current gold standards for nitrite quantification. They are not without limitations, yet have amazingly survived 156 and 44 years, respectively, due to the lack of a practical alternative.

A three-channel fluorescent probe that distinguishes peroxynitrite from hypochlorite.

A novel fluorescent probe for peroxynitrite, PN(600), was rationally designed on the basis of a unique fluorophore assembly approach. PN(600) is a green-emitting coumarin derivative. Upon oxidation by peroxynitrite, PN(600) is transformed into a highly fluorescent red-emitting resorufin derivative via an orange-emitting intermediate.