1.2- dimethyl-3-hydroxy-4-pyridinone

Comparisons of Stability Constants (Log K f for Selected Complexes of Kojate AND OF 1,2-Dimethyl-3-hydroxy-4-pyridinonate with Those for a Range of Other... 

Figure 16 Structure of (a) tris(maltolato)vanadium(III) and the ligands (b) maltol, (c) ethylmaltol, (d) kojic acid, and (e) 1,2-dimethyl-3-hydroxy-4-pyridinone...

Figure 21 Molecular structure of Ga(dpp)3 Hdpp = 3-hydroxy-l, 2-dimethyl-4-pyridinonate...

Pyridin-4-one, 1 -hydroxy-2,6-dimethyl-hydrogen-deuterium exchange reactions, 2, 196 Pyridin-4-one, 1-methyl-hydrogen-deuterium exchange, 2, 287 pK 2, 150 Pyridin-2-one imine tautomerism, 2, 158 Pyridin-2-one imine, 1-methyl-quaternization, 4, 503 Pyridin-4-one imine tautomerism, 2, 158 Pyridinone methides, 2, 331 tautomerism, 2, 158 Pyridinones acylation, 2, 352 alkylation, 2, 349 aromaticity, 2, 148 association... 

The pharmacological properties of 108 are not ideal. It removes iron only slowly and it is not well absorbed by oral administration so it has to be administered by injection. Therefore there is need for new chelators. The orally active chelator l,2-dimethyl-3-hydroxypyridin-4-one (LI) 109 is on clinical trial for the treatment of thalassemia (543). Several other chelators which contain 3-hydroxy-4(H)-pyridinone such as 110-112 also possess oral availability, and have comparable activity to 109 for the removal of iron from the liver (544, 545). These... 

To put hydroxypyranonate and hydroxypyridinonate complexes in context, stability constants for kojate and l,2-dimethyl-3-hydroxy-4-pyridinonate complexes of Mg, Al, Fe, and Gd are compared with stability constants for complexes of these cations with a few other ligands in Table III. That these hydroxypyranonate and hydroxyp5rr-idinonate ligands form stable complexes is immediately apparent. In this section we shall present and discuss a generous, but far from... 

Fig. 9. Normalized solubilities of l,2-dimethyl-3-hydroxy-4-pyridinone, dmppH, of its aluminum(III) and iron(III) complexes AKdmppla and Fe(dmpp)s, and of the 3-hydroxy-4-pyronate complexes Ga(malt)3 and In(etmalt)3 in methanol-water mixtures at 298.2 K (data from Refs. (114) and (234)).

Figure 1 Transfer chemical potentials for selected iron complexes from water into aqueous methanol (on the molar scale, at 298 K). Ligand abbreviations not appearing in the list at the end of this chapter are acac = acetylacetonate (2,4-pentanedionate) dmpp = l,2-dimethyl-3-hydroxy-4-pyridinonate, the anion from (24) malt = maltolate (2-methyl-3-hydroxy-4-pyranonate, the anion from (233)).

Job plots have established the stoichiometry of several iron(III)-3-hydroxy-2-methyl-4(l//)-pyridinone systems in aqueous solution.Stability constants have been determined for 1,2-dimethyl-, 1,2-diethyl-, and several other 3-hydroxy-4-pyridinonato-iron(III) complexes. " These data supplement and update the long-standing set of log / 3 values for... 

The kinetics of removal of iron(III) from its complexes with the aminocarboxylate-anthraquinone analytical reagent calcein and with the antitumor anthracycline doxorubicin by l,2-dimethyl-3-hydroxy-4-pyridinone (LI, (251) with R = R = Me) have been monitored. Rate constants for metal removal are almost independent of the concentration of the replacing ligand, indicating dissociative mechanisms they are approximately 1 x 10 s for displacement from doxorubin and between 12 x 10 s and 2 x 10 s from calcein. 

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