4-[(2-Amino-acetyl)-methyl-amino]-piperidine-1-carboxylic acid benzyl ester

4-[(2-Amino-acetyl)-cyclopropyl-amino]-piperidine-1-carboxylic acid benzyl ester

(S)-3-((S)-2-Amino-propionylamino)-piperidine-1-carboxylic acid benzyl ester

2-{[((S)-2-Amino-propionyl)-methyl-amino]-methyl}-pyrrolidine-1-carboxylic acid benzyl ester

4-{[((S)-2-Amino-propionyl)-methyl-amino]-methyl}-piperidine-1-carboxylic acid benzyl ester

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

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

3-[((S)-2-Amino-propionyl)-cyclopropyl-amino]-pyrrolidine-1-carboxylic acid benzyl ester

(S)-3-[((S)-2-Amino-propionyl)-cyclopropyl-amino]-piperidine-1-carboxylic acid benzyl ester

{2-[((S)-2-Amino-propionyl)-cyclopropyl-amino]-cyclohexyl}-carbamic acid benzyl ester

3-((S)-2-Amino-3-methyl-butyrylamino)-piperidine-1-carboxylic acid benzyl ester