L-Glutamic acid and L-lysine as useful building blocks for the preparation of bifunctional DTPA-like ligands

Bioconjug Chem. 1999 Jan-Feb;10(1):137-40. doi: 10.1021/bc970212u.


Bisalkylation of suitably protected L-glutamic acid and L-lysine derivatives with tert-butyl N-(2-bromoethyl)iminodiacetate 2, followed by deprotection of the omega functional group affords N, N-bis[2-[bis[2-(1, 1-dimethylethoxy)-2-oxoethyl]amino]ethyl]-L-glutamic acid 1-(1, 1-dimethylethyl) ester 4 and N2,N2-bis[2-[bis[2-(1, 1-dimethylethoxy)-2-oxoethyl]amino]ethyl]-L-lysine 1,1-dimethylethyl ester 7. Such compounds feature a carboxylic or an amino group, respectively, which are available for conjugation with a suitable partner via formation of an amide bond. The conjugates, which can be prepared in this way, contain a chelating subunit in which all five acetic residues of DTPA are available for the complexation of metal ions. Direct bisalkylation of glycine with 2 promptly gives N, N-bis[2-[bis[2-(1,1-dimethylethoxy)-2-oxoethyl]amino]ethyl]glycine 11. The latter allows to achieve conjugates in which the central acetic group of DTPA is selectively converted into an acetamide.

MeSH terms

  • Alkylation
  • Chelating Agents / chemical synthesis*
  • Chelating Agents / chemistry
  • Glutamic Acid / chemistry*
  • Ligands
  • Lysine / chemistry*
  • Pentetic Acid / chemistry*


  • Chelating Agents
  • Ligands
  • Glutamic Acid
  • Pentetic Acid
  • Lysine