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

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

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

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

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

(1R,4R)-[4-((S)-2-Amino-3-methyl-butyrylamino)-cyclohexyl]-carbamic acid benzyl ester

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

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

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

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

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