Studies of Pyrrolo[1,2-<i>a</i>]benzimidazolequinone DT-Diaphorase Substrate Activity, Topoisomerase II Inhibition Activity, and DNA Reductive Alkylation
作者:Edward B. Skibo、Samantha Gordon、Laura Bess、Romesh Boruah、Matthew J. Heileman
DOI:10.1021/jm960546p
日期:1997.4.1
activity, topoisomerase II inhibition activity, and DNA reductive alkylation was studied for the 6-aziridinylpyrrolo[1,2-alpha]benzimidazolequinones (PBIs) and the 6-acetamidopyrrolo[1,2-alpha]benzimidazolequinones (APBIs). The PBIs are reductively activated by DT-diaphorase and alkylate the phosphate backbone of DNA via major groove interactions, while the APBIs are reductively inactivated by this enzyme
研究了6-叠氮基吡咯并[1,2-α]苯并咪唑醌(PBI)和6-乙酰氨基吡咯并[1,2-α]对DT-黄递酶底物活性,拓扑异构酶II抑制活性和DNA还原烷基化的结构的影响。苯并咪唑醌(APBI)。PBI被DT-心肌黄递酶还原活化,并通过主要的沟相互作用将DNA的磷酸骨架烷基化,而APBI被该酶还原失活,因为只有醌形式抑制拓扑异构酶II。对于PBI和APBI,在7位大体积(丁基而不是甲基)显着降低了k(cat)/ K(m)的DT-黄递酶还原酶活性。结果,7-丁基PBI具有很少的细胞毒性,而7-丁基APBI具有增强的细胞毒性。PBI和APBI的3位取代基的类型以及3位的构型在较小程度上影响DT-黄递酶底物的活性。在7位的本体(丁基而不是甲基)对APBI拓扑异构酶II的抑制有不利影响,而3位的构型对该酶的抑制则有不利或积极的影响。当3-位的构型被氢键供体取代时,会影响DNA均聚物的PBI还原烷基化。