IODOACETYLATED OUABAGENINS - THEIR SYNTHESES, SPECTROSCOPIC CHARACTERIZATIONS, AND STABILITY STUDIES

Ouabain shows high binding ability to myocardial Na+,K+-ATPase and, th erefore, a suitably radiolabeled derivative of this compound may find use in myocardial imaging. In this pilot experiment we report the prep aration of several chloroacetylated and iodoacetylated ouabagenins. Th ese intermediates may possess the potential for conversion to Tc-99m-l abeled tracer by a reported procedure with which the imaging of myocar dial Na+,K+-ATPase may be possible. Appropriate analytical and spectro scopic data for these intermediates are reported for the first time. T o determine the stability of the iodoacetylated ouabagenins, correspon ding I-131 derivatives were synthesized which showed sufficient stabil ity for incorporating a suitable radiometal-binding chelating moiety t o these steroid molecules.