Structure-Activity Studies of Nitroreductase-Responsive Near-Infrared Heptamethine Cyanine Fluorescent Probes.

ABSTRACT: Two new classes of near-infrared molecular probes were prepared and shown to exhibit "turn on" fluorescence when cleaved by the nitroreductase enzyme, a well-known biomarker of cell hypoxia. The fluorescent probes are heptamethine cyanine dyes with a central 4'-carboxylic ester group on the heptamethine chain that is converted by a self-immolative fragmentation mechanism to a 4'-caboxylate group that greatly enhances the fluorescence brightness. Each compound was prepared by ring opening of a Zincke salt. The chemical structures have either terminal benzoindolinenes or propargyloxy auxochromes, which provide favorable red-shifted absorption/emission wavelengths and a hyperchromic effect that enhances the photon output when excited by 808 nm light. A fluorescent probe with terminal propargy

SUBMITTER: Morsby JJ 

PROVIDER: S-EPMC10846533 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature