Amino Acids are the feedstock for peptide and peptoid derivatives. Un-natural analogues are useful to explore protein structure activity relationships; in many cases they give rise to peptidomimetics with increased proteolytic stability. At the EnamineStore you will find a wide range of alpha aminoacids and examples of beta and gamma analogues, many incorporate features such as adamantly, cyclo-butyl, and spiro-systems along with heterocyclic ring systems including tetrazoles and imidazoles. Moreover, there are numerous examples of appropriate protecting groups: include Fmoc, Boc, and Bn for the amine group and tBu, Bn, Me and Et esters. See examples below: