[{"from": "human", "value": "Describe this molecule. [C][C][=Branch1][C][=O][N][C@@H1][Branch1][#Branch1][C][S][C][C][C][O][C][=Branch1][C][=O][O]"}, {"from": "gpt", "value": "The molecule is a modified form of acetylcysteine that is a metabolite of acrolein and may be found in the urine of smokers."}]