[{"from": "human", "value": "Provide a description of this molecule. [C][C][C][=C][C][=C][C][=C][C][=C][C][C][C][C][C][C][C][C][=Branch1][C][=O][O]"}, {"from": "gpt", "value": "The molecule is a polyunsaturated long-chain fatty acid with an 18-carbon backbone and 4 double bonds originating from the 3rd, 5th, 7th and 9th positions from the methyl end."}]