[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is an amino acid zwitterion resulting from a transfer of a proton from the carboxy group to the amino group of (2S,3S)-beta-methylphenylalanine; major species at pH 7.3. It is a tautomer of a (2S,3S)-beta-methylphenylalanine."}, {"from": "gpt", "value": "[C][C@@H1][Branch1][=Branch2][C][=C][C][=C][C][=C][Ring1][=Branch1][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O-1][NH3+1]"}]