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

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

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

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

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

(4-Benzyloxycarbonylamino-cyclohexylamino)-acetic acid

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

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

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

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

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