this compound , five possible metabolic products ( containing residues 1 -- 8 , 2 -- 9 , 2 -- 8 , 1 -- 4 , and 5 -- 9 ) , two nonapeptide analogues with two amino acids exchanged , and a related tripeptide ( trp-ser-glu ) were synthesized .
C0002520
amino acids
C0061472
glu