Structural requirements for stable binding of technetium-99m to derivatives of triglycine

✍ Scribed by Hubert P. Vanbilloen; Roger Busson; Alfons M. Verbruggen

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: French
• Weight: 529 KB
• Volume: 44
• Category: Article
• ISSN: 0022-2135
• DOI: 10.1002/jlcr.435

✦ Synopsis

Abstract

To study the importance of the thiol function of mercaptoacetyltriglycine (MAG3) for complexing technetium, we investigated a number of derivatives wherein the thiol function of MAG3, is replaced by other metal binding groups such as 3‐nitropropionyl, thiophene‐2‐carbonyl, pyrrole‐2‐carbonyl, acetoacetyl, hydroxyacetyl, picolyl or aminoacetyl. These groups have the potential to form a bond with Tc via a free electron pair or the loss of a proton.

3‐Nitropropionyltriglycine, thiophene‐2‐carbonyltriglycine and pyrrole‐2‐carbonyl‐triglycine were not able to form a single complex with ^99m^Tc. Under the experimental conditions, acetoacetyltriglycine forms a rather unstable ^99m^Tc‐complex. On the other hand, the acetoacetyl group possesses sufficient complexing capacity to serve as the fourth coordination site of a tetraligand with a strongly technetium binding thiol and two amides. Hydroxyacetyltriglycine and derivatives of MAG3 in which the thiol group is substituted by an aromatic amine, as in picolyltriglycine, or an aliphatic amine, as in tetraglycine and other tetrapeptides, form complexes with technetium‐99m which are stable for several hours. Copyright © 2001 John Wiley & Sons, Ltd.