[{"from": "human", "value": "Provide a description of this molecule. [C][C][=C][Branch2][Ring2][#Branch1][C][=Branch1][C][=O][C][=C][Branch1][Branch1][C][Ring1][#Branch1][=O][N][C][C@H1][C@@H1][Branch1][P][C@@][Ring1][Branch1][Branch1][O][C@H1][Ring1][#Branch2][C][O][C][=Branch1][C][=O][N][O][N][Ring1][O][C][O][C]"}, {"from": "gpt", "value": "The molecule is a methylazirinopyrroloindoledione antineoplastic antibiotic isolated from the bacterium Streptomyces caespitosus.  Bioreduced mitomycin B generates oxygen radicals, alkylates DNA, and produces interstrand DNA cross-links, thereby inhibiting DNA synthesis. (NCI04)"}]