Synthesis and biological characteristics of the Technetium-99m triamide derivatives of mercaptoacetyltriglycine (MAG3)

A number of MAG3‐derivatives, containing the three‐amide functions modified by inverting the sequence –CO–NH– to –NH–CO– in the first‐ and/or second‐amide functions, have been labelled with 99mTc in order to study the renal characteristics of the resulting MAG3‐derivatives versus the reference 99mTc‐MAG3. The 99mTc‐MAG3‐derivatives displayed HPLC‐profiles similar to that of 99mTc‐MAG3. Furthermore, in mice they exhibited biological behaviour comparable or even superior to 99mTc‐MAG3, which indicates that the sequence of the first‐ and/or second‐amide bond in 99mTc‐MAG3 affects the biological behaviour only to a limited degree. However, in baboon the plasma clearance of the 99mTc‐MAG3‐derivatives was relatively slower than 99mTc‐MAG3, which underlines the inter‐species variability. Copyright © 2002 John Wiley & Sons, Ltd.