The selective quantification of iron by hexadentate fluorescent probes.
The synthesis of four hexadentate fluorescent probes is described, where the fluorescent moiety is based on either coumarin or fluorescein and the chelating moiety is based on either 3-hydroxypyridin-4-one or 3-hydroxypyran-4-one. The fluorescence is quenched when the probe chelating moieties bind iron. The probes were found to be selective for iron over other metals such as Cu, Zn, Ni, Mn and Co. The effect of Cu on fluorescence quenching can be eliminated in the presence of N,N,N',N'-tetrakis(2-pyridylmethyl)-ethylenediamine. Competition studies demonstrate that the exchange of iron between pyridinone-based probes and apotransferrin is very slow. The ability to scavenge iron from oligomeric iron(III) citrate complexes demonstrate that the pyridinone probes scavenges iron faster than deferiprone and desferrioxamine. The fluorescence intensity of the fluorescein-based probe is quantitatively related to the iron concentration with the limit of detection being 10(-8)M.
Department of Pharmacy, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK.
Yong Min
YM
Ma
Robert C
RC
Hider
D003374:Coumarins / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D005452:Fluoresceins / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D007501:Iron / Q000097:blood*; D007502:Iron Chelating Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D013050:Spectrometry, Fluorescence; D016339:Spectrometry, Mass, Fast Atom Bombardment
D003374:Coumarins; D005452:Fluoresceins; D005456:Fluorescent Dyes; D007502:Iron Chelating Agents; D007501:Iron