[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is a monocarboxylic acid that is propionic acid in which one of the methyl hydrogens is replaced by a sulfino group. It is a monocarboxylic acid and an organosulfinic acid. It is a conjugate acid of a 3-sulfinatopropionate."}, {"from": "gpt", "value": "[C][Branch1][#Branch1][C][S][=Branch1][C][=O][O][C][=Branch1][C][=O][O]"}]