[{"from": "human", "value": "Provide a description of this molecule. [C][S][C][C][C][Branch1][=Branch1][C][=Branch1][C][=O][O][NH3+1]"}, {"from": "gpt", "value": "The molecule is a sulfur-containing amino-acid anion that is the conjugate acid of methionine, arising from protonation of the amino group. It is a conjugate acid of a methionine."}]