Na,d-Bis-Boc-D-ornithine

Benzoyl-L-citrulline methyl ester

Boc-Phe-Pro-OH

DL-a-Methylproline hydrobromide

D-Ala-Ala-OHHCl

Ala-Val-OH

D-Ala-Phe-OH

D-Leucyl-leucine

S-Trityl-D-penicillamine

Ne-2-Chloro-Z-L-lysine