PT - JOURNAL ARTICLE AU - DAVID J. LENTZ AU - GARY H. HENDERSON AU - EDWARD M. EYRING TI - Kinetics of Aqueous Iron(III) Complexation by Desferrioxamine B DP - 1973 Jul 01 TA - Molecular Pharmacology PG - 514--519 VI - 9 IP - 4 4099 - http://molpharm.aspetjournals.org/content/9/4/514.short 4100 - http://molpharm.aspetjournals.org/content/9/4/514.full SO - Mol Pharmacol1973 Jul 01; 9 AB - Light absorbance stopped-flow rate measurements have been made of the formation of a complex between iron(III) and desferrioxamine B in 0.1 M ionic strength, acidic, aqueous solution at and below 36°. The over-all second-order rate constant for the reaction iron(III) + desferrioxamine B → 1:1 complex is k2 = 2.5 x 103 M-1 sec-1 at pH 3.92 and 36°. This is of the same order of magnitude as previously reported rate constants for aqueous iron(III) complexation by various ligands. The over-all second-order rate constant for the same reaction in blood plasma for pH values ranging from 4.1 to 7.1 at 36° is the same as in aqueous solution to within experimental error. Thus, at physiological pH and temperatures the actual complexation reaction is sufficiently rapid that one may expect this ligand attached to a polymeric substrate to remove excess iron from blood more rapidly than the blood can be circulated in an extracorporeal cleansing device. ACKNOWLEDGMENTS This work was suggested by Professors Joseph D. Andrade and René S. Ramirez, who also graciously supplied much of the desferrioxamine B.