Separation of N-TFA-Glycyl and N-TFA- l -Prolyl Dipeptide Methyl Esters by Gas-chromatography

We have prepared a series of N-TFA-glycyl and N-TFA-l-prolyl dipeptide methyl ester from the corresponding dipeptide methyl esters by treating them with (TFA-Gly)2O and TFA-l-Pro-Cl, respectively. Separation of these tripeptide derivatives by G.L.C. was studied and a relationship between the amino acid compositions of the tripeptides and their qi-values (relative retention values) was observed, analogous to the case of the dipeptides previously reported.