Crystal structure of the tris 1,2-dimethyl-3-hydroxy-4-pyridinone (DMHP) complex with the Fe(III) ion

Combined chelation of bi-functional bis-hydroxypiridinone and mono-hydroxypiridinone: Synthesis, solution and in vivo evaluation

“…Due to hydrolytic processes starting at pH ffi 7, which seems to overlap the deprotonation process, the formation constants for the species FeHL 1 L 2 and FeL 1 L 2 can not be determined. Anyway, subtraction of the logarithmic values of the two stepwise deprotonation constants from the value calculated for the bis-protonated species (54.30 À 9.85 À 7.39 = 37.1; see Table 1) provides us a ''theoretical value" for the FeL 1 L 2 and this is in agreement with those generally obtain for a tris-hydroxypyridinonate Fe(III) complex [20,39].…”

“…Analysis of the potentiometric experimental data, aided by the SUPERQUAD program [37], enabled the calculation of the overall protonation constants (log b) from which the values of the stepwise protonation constants (log K) were obtained (see Table 1, which includes all the stepwise protonation constants and stability constants for all the metal-ligand system in study and others reported in literature [38][39][40][41][42][43], as detaily described and below).…”

“…The N-substituent has also a considerable effect on the lipo/ hydrophilic character of these IDA-derivatives; the arylpiperazine derivative is less hydrophilic than the unsubstituted analogue (see Table 1, which also includes the log P values reported for other related compounds (e.g. 3,4-DMHP [39]). …”

Synthesis and characterization of new β-diketo derivatives with iron chelating ability

“…We may not exclude the presence of polymeric species since this technique does not allow to distinguish between monomeric and dimeric species. The log b value of M/L 1/3 complexes with 6-GalOCH 3 and 6-GlcOCH 3 are similar to that found for 1-methyl-3-hydroxy-2-pyridinone [37]. Hydroxypiridinones are a class of bidentate ligands which possess a great affinity for Fe(III) ion and are effective iron chelators for therapeutical applications [38].…”

The Fenton Activity of Iron(III) in the Presence of Deferiprone

“…2,3 It has been suggested that both agranulocytosis 4 and arthropathy 5 are associated with the presence of the incompletely complexed iron(III) species, (deferiprone) 2 Fe III ] þ . 4 Deferiprone, being a bidentate ligand, normally forms a 3:1 complex with iron(III) at neutral pH values, [6][7][8] however, at low deferiprone concentrations (<1 mM) the 2:1 complex may also form. 9 Because iron(III) in the 2:1 complex is predicted to be coordinated by two monodentate water molecules, it is particularly susceptible to ligand exchange with both endogenous H 2 O 2 and ascorbic acid and could, in principle, redox cycle.…”