About busulphanalkylating agent , synthetic derivative of dimethane-sulfonate, antineoplastic agent.mechanism of action of busulphanalthough its mechanism of action is not fully understood, busulfan appears to act through the alkylation of dna. in the body this drug is converted into carbonium ions. these ions alkylate dna & it breaks. this inhibits the dna replication and rna transcription. busulfan depress the bone marrow function, reduces granulocyte mass and improves the clinical state.