Synthesis and biological characteristics of the Technetium‐99m triamide derivatives of mercaptoacetyltriglycine (MAG 3 )

A number of MAG 3 ‐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 99m Tc in order to study the renal characteristics of the resulting MAG 3 ‐derivatives versus the reference 99m Tc‐MAG 3 . The 99m Tc‐MAG 3 ‐derivatives displayed HPLC‐profiles similar to that of 99m Tc‐MAG 3 . Furthermore, in mice they exhibited biological behaviour comparable or even superior to 99m Tc‐MAG 3 , which indicates that the sequence of the first‐ and/or second‐amide bond in 99m Tc‐MAG 3 affects the biological behaviour only to a limited degree. However, in baboon the plasma clearance of the 99m Tc‐MAG 3 ‐derivatives was relatively slower than 99m Tc‐MAG 3 , which underlines the inter‐species variability. Copyright © 2002 John Wiley & Sons, Ltd.