[{"from": "human", "value": "Please give me some details about this molecule. [C][C][O][P][=Branch1][C][=O][Branch2][Ring1][C][C][Branch1][C][C][N][C][=Branch1][C][=O][N][Branch1][Ring2][C][C][Cl][N][=O][O][C][C]"}, {"from": "gpt", "value": "The molecule is a chloroethylating nitrosourea with antineoplastic activity. Fotemustine alkylates guanine by forming chloroethyl adducts at the 6 position of guanine, resulting in N1-guanine and N3-cytosine cross linkages, inhibition of DNA synthesis, cell cycle arrest, and finally apoptosis. This agent is lipophilic and crosses the blood-brain barrier."}]