Sigma-Aldrich
Copper
CARBOBENZYLOXY-L-NORVALYL-L-TRYPTOPHAN
CARBOBENZYLOXY-L-SERYL-L-TYROSINE METHYL ESTER
CARBOBENZYLOXY-L-TRYPTOPHYL-L-PHENYLALANINE BENZYL ESTER
CARBOBENZYLOXY-L-TYROSYL-L-PHENYLALANINE METHYL ESTER