[{"from": "human", "value": "Create a molecule that satisfies the conditions outlined in the description. The molecule is a monocarboxylic acid anion that is the conjugate base of 12-(octadecanoyloxy)octadecanoic acid, obtained by deprotonation of the carboxy group; major species at pH 7.3. It is a conjugate base of a 12-(octadecanoyloxy)octadecanoic acid."}, {"from": "gpt", "value": "[C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][=Branch1][C][=O][O][C][Branch1][#Branch1][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][=Branch1][C][=O][O-1]"}]