based on the amino acid composition of the peptide-resin samples and high pressure liquid chromatographic analyses of the protected heptapeptide amide obtained from the ammonolytic cleavage of the peptide-resin samples , it was concluded that only dicyclohexylcarbodiimide plus 4-dimethylaminopyridine gave the desired near quantitative couplings in those cycles involving the sterically hindered amino acid residues .
C0301714
based
C0002520
amino acid