It is a guanine analog and an inhibitor of the DNA repair enzyme O6 alkylguanine DNA alkyltransferase (MGMT/AGT).
O6-Benzylguanine acts as the AGT substrate, transferring the benzyl group of Chemicalbook to the cysteine residue of AGT, thereby irreversibly inactivating AGT and preventing DNA repair.
O6-Benzylguanine induces tumor cell apoptosis and has anti-tumor activity.