Deferitazole, a new orally active iron chelator

Area of Science:

• Medicinal Chemistry
• Pharmacology
• Biochemistry

Background:

• Deferitazole (FBS0701) is a novel polyether derivative developed as a therapeutic iron chelator.
• Despite promising biological properties and progression into clinical trials, its detailed physicochemical characteristics remain unreported.

Purpose of the Study:

• To comprehensively characterize the physicochemical properties of deferitazole.
• To evaluate its binding affinity and selectivity for various metal ions, particularly iron(III).
• To assess its potential as a therapeutic agent for iron overload conditions.

Main Methods:

• Systematic literature search for desferrithiocin analogs.
• Determination of metal-ion binding affinities using stability constants (log β2) and pFe(3+) values.
• Assessment of iron scavenging efficiency from labile sources.
• Evaluation of the stability and redox cycling potential of the Fe(III)-deferitazole complex under physiological conditions.

Main Results:

• Deferitazole exhibits a very high affinity and selectivity for iron(III) (log β2 = 33.39 ± 0.03, pFe(3+) = 22.3).
• Two isomeric forms of the iron(III) complex exist under physiological conditions.
• High affinity binding is also observed for Al(III) and La(III), and for Cu(II) among divalent cations.
• Deferitazole effectively scavenges iron from citrate and albumin, comparable to existing chelators like deferasirox.
• The Fe(III)(deferitazole)2 complex is stable and does not redox cycle under physiological conditions.

Conclusions:

• Deferitazole possesses strong iron(III) binding capabilities and selectivity.
• Its stability and lack of redox cycling suggest a low risk of iron redistribution.
• Deferitazole shows considerable promise as a safe and effective therapeutic iron(III) chelator.