N-烷基-DO3A钆(Ⅲ)螯合物的合成、稳定性与弛豫性能

Synthesis,Stability and Relaxivity of N-Alkyl-DO3A and Their Gd(Ⅲ) Chelates

合成了用直链烷基修饰的DO3A衍生物(H3L):N-己基-DO3A(2)、N-癸基-DO3A(3)和N-十六烷基-DO3A(4)及其钆(Ⅲ)螯合物,测得化合物2、3和4的第1级质子化常数(lgK1H)分别为10.72、10.68和10.52;相应的钆(Ⅲ)螯合物的稳定常数(lgKGdL)分别为20.50、19.60和19.25;相应的钆(Ⅲ)螯合物的水质子弛豫率(R1)分别为4.88、4.96和5.12L/(mmol·S)。结果表明,在DO3A的1,4,7,10-四氮杂环十二烷骨架上引入直链烷基,其碱性略有改变,但仍保持DO3A母体的强螯合性能和水质子弛豫率。

Synthesis of DO3A derivatives （ H3 L） modified by linear alkyl groups, N-hexyl-DO3A （2）, N- decyl-DO3 A （3）, N-hexadecyl-DO3 A （4）, and their Gd （ Ⅲ ） chelates （GdL） is described. The protonation constants of compounds 2, 3 and 4, the stability constants and the water proton relaxivity of GdL were determined. The first protonation constants（lg K1^H） of compounds 2, 3 and 4 were respectively 10. 72, 10. 68 and 10. 52, the stability constants of the corresponing GdL chelates were respectively 20. 50, 19. 60 and 19.25, and the water proton relaxivitives （r1 ） of the corresponding GdL chelates were respectively 4.88, 4. 96 and 5.12 L/（mmol · S）. The results obtained showed that the basicities of the ligands were all slightly altered, but the ligands still maintained strong chelating property and the water proton relaxivity of the parent DO3A after the introduction of a linear alkyl group at the cyclen backbone of DO3A.