The present invention provides AGT inactivating compounds such as substituted O6-benzylguanines of the formula 
7- or 9-substituted 8-aza-O6-benzylguanines, 7,8-disubstituted O6-benzylguanines, 7,9-disubstituted O6-benzylguanines, 4(6)-substituted 2-amino-5-nitro-6(4)-benzyloxypyrimidines, and 4(6)-substituted 2-amino-5-nitroso-6(4)-benzyloxypyrimidines, as well as pharmaceutical compositions comprising such compounds along with a pharmaceutically acceptable carrier. The present invention further provides a method of enhancing the chemotherapeutic treatment of tumor cells in a mammal with an antineoplastic alkylating agent which causes cytotoxic lesions at the O6-position of guanine, by administering to a mammal an effective amount of one of the aforesaid compounds, 2,4-diamino-6-benzyloxy-s-triazine, 5-substituted 2,4-diamino-6-benzyloxypyrimidines, or 8-aza-O6-benzylguanine, and administering to the mammal an effective amount of an antineoplastic alkylating agent which causes cytotoxic lesions at the O6-position of guanine.
                            本发明提供了AGT失活化合物,例如公式7-或9-取代的8-氮杂-O6-苄基
鸟嘌呤,7,8-二取代的O6-苄基
鸟嘌呤,7,9-二取代的O6-苄基
鸟嘌呤,4(6)-取代的2-
氨基-5-硝基-6(4)-苄氧
嘧啶和4(6)-取代的2-
氨基-5-亚硝基-6(4)-苄氧
嘧啶,以及包含这些化合物和药学上可接受的载体的制药组合物。本发明还提供了一种方法,在哺乳动物中通过向哺乳动物施用上述化合物之一,2,4-二
氨基-6-苄氧基-s-三嗪,5-取代的2,4-二
氨基-6-苄氧基
嘧啶,或8-氮杂-O6-苄基
鸟嘌呤的有效量,并向哺乳动物施用在
鸟嘌呤的O6位引起细胞毒性损伤的抗肿瘤烷基化剂的有效量,以增强肿瘤细胞的化疗治疗。