BATO complexes derived from dimethoxy dioximes: synthesis, characterization and biodistribution.
To prepare less lipophilic BATO complexes, two new methoxy-substituted dioximes were synthesized: cis-4,5-dimethoxycyclohexane-1,2-dione dioxime (DMCDO) and 1,4-dimethoxybutane-2,3-dione dioxime (DMDMG). 99mTcCl(DMCDO)3BMe (BMe = methylboronic acid) was prepared and characterized. Reversed-phase HPLC analyses of 99mTcCl(DMCDO)3BMe and 99mTcCl(DMCDO)3-p-TBA (p-TBA = p - tolylboronic acid) indicated that both of these complexes were mixtures of four enantiomeric pairs of diastereomers. Attempted preparation of a BATO complex from DMDMG gave a mixture of products. In rats, 99mTcCl(DMCDO)3BMe displayed more rapid liver and renal clearance than 99mTcCl(CDO)3BMe, but 99mTcCl(DMCDO)3BMe and 99mTcCl(DMCDO)3-p-TBA displayed low uptake in both heart and brain.