5-(1-Aminocyclopropyl)pyrazin-2-amine

2-(4-Cyclopropyl-1,3-thiazol-5-yl)-3-methylbutanoic acid

3-[(2S)-2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-4-(methylsulfanyl)butanoyl]-3-azabicyclo[4.1.0]heptane-7-carboxylic acid

(2S)-1-[3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)hexanoyl]-2-methylpyrrolidine-2-carboxylic acid

2-{[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-3-methoxybutanamido]methyl}-4-methylpentanoic acid

3-({3-[({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)methyl]-1-methyl-1H-pyrazol-5-yl}formamido)-2-methoxypropanoic acid

(2S)-4-({3-[({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)methyl]-1-methyl-1H-pyrazol-5-yl}formamido)-2-hydroxybutanoic acid

(2R)-2-[(2S,3R)-2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-3-methoxybutanamido]-3-methylbutanoic acid

(3S)-3-[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-2-(methoxymethyl)butanamido]-4-methylpentanoic acid

(3R)-3-{[1-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)cyclohexyl]formamido}-4-methylpentanoic acid

3-{N-ethyl-1-[3-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-1-methyl-1H-pyrazol-4-yl]formamido}butanoic acid