[{"from": "human", "value": "Describe this molecule. [C][C][O][P][=Branch1][C][=O][Branch1][S][N][C][Ring1][#Branch1][S][C][C][S][=Branch1][C][=O][=Branch1][C][=O][O][N][Branch1][Ring2][C][C][Cl][C][C][Cl]"}, {"from": "gpt", "value": "The molecule is a synthetic oxazaphosphorine derivative with antineoplastic properties.  Mafosfamide alkylates DNA, forming DNA cross-links and inhibiting DNA synthesis.  Although closely related to cyclophosphamide, mafosfamide, unlike cyclophosphamide, does not require hepatic activation to generate its active metabolite 4-hydroxy-cyclophosphamide; accordingly, mafosfamide is potentially useful in the intrathecal treatment of neoplastic meningitis. (NCI04)"}]