[{"from": "human", "value": "Create a molecule with the structure as the one described. The molecule is a methanesulfonate ester resulting from the formal condensation of methanesulfonic acid with methanol. It has a role as an alkylating agent, a genotoxin, a carcinogenic agent, a mutagen and an apoptosis inducer."}, {"from": "gpt", "value": "[C][O][S][=Branch1][C][=O][=Branch1][C][=O][C]"}]