SYNTHESIS AND BIOLOGICAL EVALUATION OF TC-99M N,N'-BIS(MERCAPTOACETYL)-2,3-DIAMINOPROPANOATE - A POTENTIAL REPLACEMENT FOR [I-131]-LABELED O-IODOHIPPURATE

Abstract

A new Tc-chelating agent based on amide and mercaptide donor groups, N,N''-bis(mercaptoacetyl)-2,3-diaminopropanoate, was synthesized as an analog of previously described N,N''-bis(mercaptoacetyl)ethylenediamine (DADS). Complexation of 99mTc with the new chelating group resulted in 2 components that were separable by high-performance liquid chromatography. The component that eluted first demonstrated high specificity for renal excretion, with > 90% in the urine of rabbits at 35 min, 87% in the urine of mice at 2 h and .ltoreq. 1.6% in the intestines of mice. Excretion was rapid, with the 1st component equaling or exceeding [131I]o-iodohippurate in the urine of rabbits at all times. The 2nd or latter component demonstrated comparable specificity but slightly slower renal excretion kinetics.