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

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

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

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

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

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

[(1-Benzyl-piperidin-4-yl)-methyl-amino]-acetic acid

[(1-Benzyl-pyrrolidin-3-ylmethyl)-ethyl-amino]-acetic acid

[(1-Benzyl-piperidin-3-ylmethyl)-ethyl-amino]-acetic acid

[((S)-1-Benzyl-pyrrolidin-2-ylmethyl)-cyclopropyl-amino]-acetic acid

[(1-Benzyl-piperidin-3-ylmethyl)-cyclopropyl-amino]-acetic acid