(S)-2-Amino-N-(1-benzyl-piperidin-2-ylmethyl)-N-ethyl-propionamide

(S)-2-Amino-N-((S)-1-benzyl-pyrrolidin-3-yl)-3,N-dimethyl-butyramide

(S)-2-Amino-N-(1-benzyl-piperidin-4-yl)-N-isopropyl-3-methyl-butyramide

(S)-2-Amino-N-((S)-1-benzyl-pyrrolidin-3-yl)-N-cyclopropyl-3-methyl-butyramide

(1-Acetyl-piperidin-3-ylamino)-acetic acid

(2-Acetylamino-cyclohexylamino)-acetic acid

[(4-Acetylamino-cyclohexyl)-methyl-amino]-acetic acid

[(1-Acetyl-piperidin-3-yl)-ethyl-amino]-acetic acid

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

[(1-Acetyl-piperidin-3-yl)-isopropyl-amino]-acetic acid

[((S)-1-Acetyl-piperidin-3-yl)-cyclopropyl-amino]-acetic acid