THE INTERACTION OF SALICYLALDEHYDEBENZOYLHYDRAZONE WITH CA2- A SPECTROPHOTOMETRIC STUDY( AND MG2+ )

This article reports a spectrophotometrical study of complex formation between Mg2+, Ca2+ and Salicylaldehydebenzoylhydrazone (SBH) with Mg2 + and Ca2+. At pH > 9.11, the unprotonated species of SBH, L forms a m onocomplex with Mg2+ (affinity constant : 4.80 x 10(3) M-1) and with C a2+ (affinity constant : 750 M-1). In neutral media, where the SBH lig and is present under the monoprotonated LH species, SBH does not posse ss any measurable affinity for Mg2+ or Ca2+ with for both metals a pM value of 5.0 for [M] = 1 x 10(-5) M, [SBH] = 1 x 10(-5) M and pH 7.4. These results are of interest for the iron-overload chelating therapy in which the chelating drug should be able to only form stable complex es with iron but not with the other metallic cations essential for the metabolism.