Design, synthesis and properties of novel iron(III)-specific fluorescent probes

Autor: Peter J. Quinn, Yong M. Ma, Wei Luo, Zu D. Liu, Robert C. Hider
Rok vydání: 2004
Předmět:
Zdroj: Journal of Pharmacy and Pharmacology. 56:529-536
ISSN: 2042-7158
0022-3573
DOI: 10.1211/0022357023196
Popis: Bidentate chelators such as hydroxypyridinones and hydroxypyranones are highly iron selective. The synthesis of two novel fluorescent probes N-[2-(3-hydroxy-2-methyl-4-oxopyridin-1(4H)-yl)ethyl]-2-(7-methoxy-2-oxo-2H-chromen-4-yl)acetamide (CP600) and N-[(3-hydroxy-6-methyl-4-oxo-4H-pyran-2-yl)methyl]-2-(7-methoxy-2-oxo-2H-chromen-4-yl)acetamide (CP610) is reported. The method involves coupling the bidentate ligands, 3-hydroxypyridin-4-one and 3-hydroxypyran-4-one, with the well-characterised fluorescent probe methoxycoumarin. Fluorescence emission of both probes at 380 nm is readily quenched by Fe3+. The fluorescence was quenched to a greater extent by Fe3+ than by Mn2+, Co2+, Zn2+, Ca2+, Mg2+, Na+ and K+ and to approximately the same extent as Cu2+. Comparison of the fluorescence-quenching ability by a range of metal ions on CP600 and CP610 and the hexadentate chelator, calcein, under in-vitro conditions, demonstrated advantages of the two novel fluorescent probes with respect to both iron(III) sensitivity and selectivity. Chelation of iron(III) by CP600 and CP610 leads to the formation of a complex with a metal-to-ligand ratio of 1:3. Fluorescence is quenched on formation of such complexes. These probes possess a molecular weight less than 400 and thus they are predicted to permeate biological membranes by passive diffusion, and have potential for reporting intracellular organelle labile iron levels.
Databáze: OpenAIRE
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