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

(S)-2-[((S)-2-Amino-3-methyl-butyrylamino)-methyl]-pyrrolidine-1-carboxylic acid benzyl ester

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

[2-((S)-2-Amino-3-methyl-butyrylamino)-cyclohexyl]-carbamic acid benzyl ester

4-{[((S)-2-Amino-3-methyl-butyryl)-methyl-amino]-methyl}-piperidine-1-carboxylic acid benzyl ester

(1R,4R)-{4-[((S)-2-Amino-3-methyl-butyryl)-methyl-amino]-cyclohexyl}-carbamic acid benzyl ester

3-{[((S)-2-Amino-3-methyl-butyryl)-ethyl-amino]-methyl}-piperidine-1-carboxylic acid benzyl ester

{4-[((S)-2-Amino-3-methyl-butyryl)-ethyl-amino]-cyclohexyl}-carbamic acid benzyl ester

(1-Benzyl-piperidin-3-ylamino)-acetic acid

[(1-Benzyl-piperidin-2-ylmethyl)-amino]-acetic acid

[(1-Benzyl-piperidin-3-yl)-methyl-amino]-acetic acid