The thulium complex of 1,4,7,10-tetrakis{[N-(1H-imidazol-2-yl)carbamoyl]methyl}-1,4,7,10-tetraazacyclododecane (dotami) as a ParaCEST contrast agent.
1,4,7,10-Tetrakis{[N-(1H-imidazol-2-yl)carbamoyl]methyl}-1,4,7,10-tetraazacyclododecane (dotami), a tetra(1H-imidazol-2-yl) derivative of the well-studied octadentate 1,4,7,10-tetrakis[(carbamoyl)methyl]-1,4,7,10-tetraazacyclododecane (dotam) ligand, was synthesized by reaction of 1,4,7,10-tetraazacyclododecane with N-(1H-imidazol-2-yl)chloroacetamide in high yield. Its tricationic thulium complex was isolated as a water-soluble chloride salt. The detection of the mildly acidic amide and amine protons by direct proton NMR in aqueous solution was unsuccessful, but such exchangeable protons could be detected via their chemical exchange-dependent saturation transfer (CEST) effect. The observed CEST effect was distinctly different from that found for respective dotam complexes and is, therefore, ascribed to exchangeable protons associated with the imidazole substituent.
Burdinski
Dirk
D
Department of Bio-Molecular Engineering, Philips Research, High Tech Campus 11, NL-5656 AE Eindhoven (phone: +31-40-27-48254; fax: +31-40-27-44906).
Lub
Johan
J
Department of Bio-Molecular Engineering, Philips Research, High Tech Campus 11, NL-5656 AE Eindhoven (phone: +31-40-27-48254; fax: +31-40-27-44906).
Pikkemaat
Jeroen A
JA
Department of Materials Analysis, Philips Research, High Tech Campus 11, NL-5656 AE Eindhoven.
Langereis
Sander
S
Department of Bio-Molecular Engineering, Philips Research, High Tech Campus 11, NL-5656 AE Eindhoven (phone: +31-40-27-48254; fax: +31-40-27-44906).
Grüll
Holger
H
Department of Bio-Molecular Engineering, Philips Research, High Tech Campus 11, NL-5656 AE Eindhoven (phone: +31-40-27-48254; fax: +31-40-27-44906).
Ten Hoeve
Wolter
W
Syncom B. V., Kadijk 3, NL-9747 AT Groningen.
D000577:Amides / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D003287:Contrast Media / Q000138:chemical synthesis / Q000737:chemistry*; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000592:standards; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011522:Protons; D012015:Reference Standards; D013237:Stereoisomerism; D013932:Thulium / Q000737:chemistry*
C533989:(1,4,7,10-tetrakis((N-(1H-imidazol-2-yl)carbamoyl)methyl)-1,4,7,10-tetraazacyclododecane)thulium(III); D000577:Amides; D000588:Amines; D003287:Contrast Media; D008024:Ligands; D009942:Organometallic Compounds; D011522:Protons; D013932:Thulium