(S)-2-Amino-1-[(R)-3-(benzyl-cyclopropyl-amino)-piperidin-1-yl]-3-methyl-butan-1-one

3-((S)-2-Amino-propionylamino)-piperidine-1-carboxylic acid tert-butylester

[4-((S)-2-Amino-propionylamino)-cyclohexyl]-carbamic acid tert-butyl ester

{4-[((S)-2-Amino-propionyl)-methyl-amino]-cyclohexyl}-carbamic acid tert-butyl ester

(R)-3-[((S)-2-Amino-propionyl)-ethyl-amino]-piperidine-1-carboxylic acid tert-butyl ester

(S)-3-[((S)-2-Amino-propionyl)-isopropyl-amino]-pyrrolidine-1-carboxylic acid tert-butyl ester

(1R,4R)-{4-[((S)-2-Amino-propionyl)-isopropyl-amino]-cyclohexyl}-carbamic acid tert-butyl ester

3-{[((S)-2-Amino-propionyl)-cyclopropyl-amino]-methyl}-piperidine-1-carboxylic acid tert-butyl ester

2-[((S)-2-Amino-3-methyl-butyrylamino)-methyl]-piperidine-1-carboxylic acid tert-butyl ester

(S)-2-{[((S)-2-Amino-3-methyl-butyryl)-methyl-amino]-methyl}-pyrrolidine-1-carboxylic acid tert-butyl ester

(S)-3-[((S)-2-Amino-3-methyl-butyryl)-methyl-amino]-piperidine-1-carboxylic acid tert-butyl ester