Five DTPA-bis(amide)s have been synthesized and characterized by means of ^(1)H NMR , FT-IR and elemental analyses. The stability constants of their Gd^(3+) complexes have been measured using a simple spectrophotomet...Five DTPA-bis(amide)s have been synthesized and characterized by means of ^(1)H NMR , FT-IR and elemental analyses. The stability constants of their Gd^(3+) complexes have been measured using a simple spectrophotometric method. The results show that the complexing properties of the ligands in comparison with those of DTPA are affected by converting two carboxyl groups to amide groups. The relaxation studies have shown that the relaxivity of the chelates is similar to that of Gd-DTPA, indicating that in solution all the chelates have one water molecule directly coordinated to the metal ion. Only one water molecule in inner coordination sphere suggests the coordination of the carboxamide oxygen to gadolinium ion, which agrees with the FT-IR results.展开更多
DTPA was covalently conjugated to the copolymer of L-lysine and L-tyrosine,then transchelated with Gd-EDTA,the resultant polymer chelates were further reacted with 6-O-bromoacetyl-D-galactose or methyl lactobionyloxya...DTPA was covalently conjugated to the copolymer of L-lysine and L-tyrosine,then transchelated with Gd-EDTA,the resultant polymer chelates were further reacted with 6-O-bromoacetyl-D-galactose or methyl lactobionyloxyacetate to give PLT(Gd-DTPA)with galactose moiety as liver-targeting group.These macromolecular MRI contrast agents were characterized by means of FT-IR,ICP-AES,elementary analyses and UV-Vis spectrophotometry.Their in vitro relaxivity and liver targeting property in mice were also investigated.展开更多
文摘Five DTPA-bis(amide)s have been synthesized and characterized by means of ^(1)H NMR , FT-IR and elemental analyses. The stability constants of their Gd^(3+) complexes have been measured using a simple spectrophotometric method. The results show that the complexing properties of the ligands in comparison with those of DTPA are affected by converting two carboxyl groups to amide groups. The relaxation studies have shown that the relaxivity of the chelates is similar to that of Gd-DTPA, indicating that in solution all the chelates have one water molecule directly coordinated to the metal ion. Only one water molecule in inner coordination sphere suggests the coordination of the carboxamide oxygen to gadolinium ion, which agrees with the FT-IR results.
文摘DTPA was covalently conjugated to the copolymer of L-lysine and L-tyrosine,then transchelated with Gd-EDTA,the resultant polymer chelates were further reacted with 6-O-bromoacetyl-D-galactose or methyl lactobionyloxyacetate to give PLT(Gd-DTPA)with galactose moiety as liver-targeting group.These macromolecular MRI contrast agents were characterized by means of FT-IR,ICP-AES,elementary analyses and UV-Vis spectrophotometry.Their in vitro relaxivity and liver targeting property in mice were also investigated.
