O6-benzylguanine

A guanine analogue with antineoplastic activity. O(6)-benzylguanine binds the DNA repair enzyme O(6)-alkylguanine DNA alkyltransferase (AGT), transferring the benzyl moiety to the active-site cysteine and resulting in inhibition of AGT-mediated DNA repair. Co-administration of this agent potentiates the effects of other chemotherapeutic agents that damage DNA.