申请人:Arizona Board of Regents acting on behalf of Arizona State University
公开号:US05639881A1
公开(公告)日:1997-06-17
Pyrimido[4,5-g]quinazoline quinone derivatives were synthesized as anthranone-like reductive alkylating agents. Like many naturally-occurring antibiotics, these quinone derivatives are designed to afford an alkylating quinone methide species upon reduction and leaving group elimination. Kinetic studies of pyrimido[4,5-g]quinazoline hydroquinones provided evidence of quinone methide intermediates able to trap nucleophiles (alkylation) and protons. The rate of quinone methide formation is determined by the hydroquinone free energy. Thus, a linear free energy relationship for quinone methide formation was obtained by plotting rates of quinone methide formation, as the log, versus the quinone reduction potential. The pyrimido[4-5-g]quinazoline quinone methides fall on this free energy plot, showing that these species are formed by the same mechanism as the other structurally-diverse quinone methides previously studied in this research group. A drawback of many quinone antibiotics, particularly the anthracyclines, is the formation of toxic oxygen species by quinone/hydroquinone cycling. In the present invention pyrimido[4,5-g]quinazoline hydroquinones are found to be relatively stable toward oxygen, and thus cause little oxygen toxicity. Antitumor screening revealed that the disclosed pyrimido[4,5-g]quinazoline dione derivatives possess excellent inhibitory activity against selected human cancer cell lines. The pyrimido[4,5g]quinazoline-diones have the following structural formulae: ##STR1## wherein: R is H or CH.sub.3 ; and X is Cl or Br.
合成了吡咯并[4,5-g]喹唑啉醌衍生物作为类蒽醌样还原烷基化试剂。与许多天然存在的抗生素一样,这些醌衍生物被设计为在还原和离去基团消除后形成烷基化醌甲烯物种。对吡咯并[4,5-g]喹唑啉氢醌的动力学研究提供了醌甲烯中间体能够捕获亲核试剂(烷基化)和质子的证据。醌甲烯形成速率由氢醌的自由能确定。因此,通过绘制醌甲烯形成速率的对数与醌还原电位之间的关系图,获得了醌甲烯形成的线性自由能关系。吡咯并[4-5-g]喹唑啉醌甲烯落在这一自由能图上,表明这些物种是通过与此前在该研究小组中研究的其他结构多样的醌甲烯相同的机制形成的。许多醌类抗生素,特别是蒽环素,存在通过醌/氢醌循环形成有毒氧物种的缺点。在本发明中发现,吡咯并[4,5-g]喹唑啉氢醌对氧相对稳定,因此引起的氧毒性较小。抗肿瘤筛选显示,所披露的吡咯并[4,5-g]喹唑啉二酮衍生物对选定的人类癌细胞系具有出色的抑制活性。吡咯并[4,5-g]喹唑啉-二酮具有以下结构式:其中:R为H或CH3;X为Cl或Br。