[{"from": "human", "value": "Describe this molecule. [C][C][=Branch1][C][=O][N][C][C][S][C][C][C][Branch1][=Branch1][C][=Branch1][C][=O][O-1][NH3+1]"}, {"from": "gpt", "value": "The molecule is major microspecies at pH 7.3. It is a homocysteine derivative and a zwitterion."}]