[(S)-2-((S)-3-Benzyl-1,4-dioxo-hexahydro-pyrrolo[1,2-a]pyrazin-2-yl)-1-hydroxymethyl-2-oxo-ethyl]-carbamic acid tert-butyl ester

(L-Valyl)-L-phenylalanyl-L-prolin-lactam

N-(9,10-Dihydrolysergyl-O-benzyl-L-seryl)-L-phenylalanyl-L-prolin-lactam

3-benzylhexahydropyrrolo[1,2-a]pyrazine-1,4-dione