title: Conferring Phosphorogenic Properties on Iridium(III)-Based Bioorthogonal Probes through Modification with a Nitrone Unit.
abstract: The use of bioorthogonal probes that display fluorogenic or phosphorogenic properties is advantageous to the labeling and imaging of biomolecules in live cells and organisms. Herein we present the design of three iridium(III) complexes containing a nitrone moiety as novel phosphorogenic bioorthogonal probes. These probes were non-emissive owing to isomerization of the C=N group but showed significant emission enhancement upon cycloaddition reaction with strained cyclooctynes. Interestingly, the connection of the nitrone ligand to the cationic iridium(III) center led to accelerated reaction kinetics. These nitrone complexes were also identified as phosphorogenic bioorthogonal labels and imaging reagents for cyclooctyne-modified proteins. These findings contribute to the development of phosphorogenic bioorthogonal probes and imaging reagents.
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, P.R. China.
authors.forename: Lawrence Cho-Cheung
authors.initials: LC
authors.lastname: Lee
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, P.R. China.
authors.forename: Jonathan Chun-Wai
authors.initials: JC
authors.lastname: Lau
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, P.R. China.
authors.forename: Hua-Wei
authors.initials: HW
authors.lastname: Liu
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, P.R. China. bhkenlo@cityu.edu.hk.|State Key Laboratory of Millimeter Waves, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (P.R., China. bhkenlo@cityu.edu.hk.
authors.forename: Kenneth Kam-Wing
authors.identifier: http://orcid.org/0000-0002-2470-5916
authors.initials: KK
authors.lastname: Lo
mesh_terms: D007495:Iridium / Q000737:chemistry*; D015335:Molecular Probes; D009589:Nitrogen Oxides / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry*
chemical_list: D015335:Molecular Probes; D009589:Nitrogen Oxides; C015388:nitrones; D010758:Phosphorus; D007495:Iridium
keywords: bioorthogonal; imaging agents; iridium; nitrone; phosphorogenic probes