[{"from": "human", "value": "Provide a description of this molecule. [C][C][C][C][C][=Branch1][C][=O][O][Ring1][=Branch1]"}, {"from": "gpt", "value": "The molecule is a butan-4-olide that is dihydrofuran-2(3H)-one substituted by a methyl group at position 5. It has been found in the urine samples of humans exposed to n-hexane. It has a role as a flavouring agent and a human xenobiotic metabolite."}]