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

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

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

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

4-[(Carboxymethyl-amino)-methyl]-piperidine-1-carboxylic acid benzyl ester

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

[(2-Benzyloxycarbonylamino-cyclohexyl)-ethyl-amino]-acetic acid

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

2-[(Carboxymethyl-cyclopropyl-amino)-methyl]-piperidine-1-carboxylic acid benzyl ester

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

(1R,4R)-{4-[(2-Hydroxy-ethyl)-methyl-amino]-cyclohexyl}-carbamic acid benzyl ester