D－Alanine D－Threonine D－Methionine D－Valine D－Tryptophan DL－Valine DL－Threonine DL－Methionine L－Tryptophan L－Methionine L－Threonine L－Lysine Hydrochloride N－Acetyl－DL－Methionine N－Acetyl－L－Methionine