[{"from": "human", "value": "Provide a brief overview of this molecule. [C][C][C][=C][Branch2][#Branch1][Ring1][C][=C][C][=C][Branch2][=Branch1][#Branch2][C][=Branch2][=Branch1][Branch1][=C][Branch1][Ring2][N-1][Ring1][Branch1][C][=C][C@][Branch2][Ring2][#Branch1][C@@H1][Branch2][Ring2][C][C][=Branch1][Ring2][=N][Ring1][Branch1][C][=C][C][=Branch2][Ring1][Ring2][=C][Branch1][S][C][=Branch1][Ring2][=N][Ring1][Branch1][C][=C][Ring2][Ring1][#Branch1][N-1][Ring2][Ring1][=Branch1][C][C][C][C][Branch1][#C][C][=Branch1][Branch1][=C][Ring2][Ring1][Branch1][C][=Branch1][C][=O][O][C][C][C][C][C][C][C][C].[Cl-1].[Sn+4]"}, {"from": "gpt", "value": "The molecule is a synthetic purpurin with photosensitizing activity.  Tin ethyl etiopurpurin preferentially accumulates in tumor cells due to an increased rate of metabolism. Upon exposure to a light source, this agent absorbs light, forming an extended high energy conformational state that produces high quantum yields of singlet oxygen with local cytotoxic effects. (NCI04)"}]