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

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

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

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

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

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

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

(1-Benzyl-piperidin-4-ylamino)-acetic acid

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