N-Acetyl-L-Tryptophen N-Acetyl-D-Tryptophen N-Acetyl-L-Leucine N-Acetyl-D-Leucine N-Acetyl-L-Proline N-Acetyl-D-Proline N-Acetyl-L-Glutamine N-Acetyl-L-Phenylalanine N-Acetyl-DL-Tryptophen N-Acetylglycine