[{"from": "human", "value": "Based on the given information, design a molecule that meets the desired specifications. The molecule is an unsaturated fatty acid anion resulting from the deprotonation of the carboxy group of petroselaidic acid. The major species at pH 7.3. It is a long-chain fatty acid anion and an unsaturated fatty acid anion. It is a conjugate base of a petroselaidic 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-1]"}]