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

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

3-[((S)-2-Amino-3-methyl-butyryl)-isopropyl-amino]-pyrrolidine-1-carboxylic acid tert-butyl ester

2-{[((S)-2-Amino-3-methyl-butyryl)-isopropyl-amino]-methyl}-piperidine-1-carboxylic acid tert-butyl ester

3-{[((S)-2-Amino-3-methyl-butyryl)-cyclopropyl-amino]-methyl}-pyrrolidine-1-carboxylic acid tert-butyl ester

3-[(Carboxymethyl-amino)-methyl]-pyrrolidine-1-carboxylic acid benzyl ester

3-(Carboxymethyl-ethyl-amino)-pyrrolidine-1-carboxylic acid benzyl ester

4-(Carboxymethyl-ethyl-amino)-piperidine-1-carboxylic acid benzyl ester

(R)-3-(Carboxymethyl-isopropyl-amino)-pyrrolidine-1-carboxylic acid benzyl ester

(1R,4R)-[(4-Benzyloxycarbonylamino-cyclohexyl)-isopropyl-amino]-acetic acid

4-(Carboxymethyl-cyclopropyl-amino)-piperidine-1-carboxylic acid benzyl ester