A novel mitochondria-localizing nitrobenzene derivative as a donor for photo-uncaging of nitric oxide.

We report a novel green-fluorescent NO donor, NBDNO, bearing a 2,6-dimethylnitrobenzene moiety for photocontrollable NO release and a triphenylphosphonium moiety for targeting to mitochondria. Photorelease of NO from NBDNO was confirmed by means of ESR analysis in aqueous solution. Intracellular release of NO from NBDNO was confirmed by using DAR-4M AM, an NO-specific fluorescence probe. NBDNO was colocalized with MitoRed, a mitochondrial stain, in HCT116 colon cancer cells. Our results indicate that NBDNO is an effective NO donor for time-controlled, mitochondria-specific NO treatment.