Synthesis of deuterated aminocaproyl linkers

Gramicidin A (gA) analogues with a biotin attached to the C-terminus by an aminocaproyl linker are used as ion channels in the AMBRI(R) biosensor and are referred to as biotinylated gA. In order to examine the conformation and dynamics of the aminocaproyl linker by H-2 solid-state nuclear magnetic resonance, the synthesis of deuterated aminocaproic acid is required. We report on the synthesis of (D-10)-6-aminocaproic acid from commercially available perdeuterated cyclohexanol and its covalent attachment to the C-terminal group of gA to form gAX(D)XB.