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 propargyloxy‐indolenines exhibited less self‐aggregation and was rapidly activated by nitroreductase with large “turn on“ fluorescence; thus, it is the preferred choice for translation towards in vivo applications.

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch

References and Relationships

• Bibliographic citation: Structure‐Activity Studies of Nitroreductase‐Responsive Near‐Infrared Heptamethine Cyanine Fluorescent Probes ; day:12 ; month:04 ; year:2022 ; extent:1 ; European journal of organic chemistry ; (12.04.2022) (gesamt 1)

Contributors, Places and Time

• Creator: Morsby, Janeala J. ; Atkinson, Kirk M. ; Shradha Reddy Kommidi, Sai ; Freel, Tristan ; Janeková, Hana ; Štacko, Peter ; Smith, Bradley D.

Further information

• DOI: 10.1002/ejoc.202200270
• URN: urn:nbn:de:101:1-2022041315044561121741
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 15.08.2025, 7:37 AM CEST