Hypoxia-Selective Antitumor Agents. 13. Effects of Acridine Substitution on the Hypoxia-Selective Cytotoxicity and Metabolic Reduction of the Bis-bioreductive Agent Nitracrine <i>N</i>-Oxide
作者:Ho H. Lee、William R. Wilson、Dianne M. Ferry、Pierre van Zijl、Susan M. Pullen、William A. Denny
DOI:10.1021/jm9600104
日期:1996.1.1
N-oxides all showed greater metabolic stability than 2 in hypoxic AA8 cell cultures, and the 4-OMe compound 6 had improved activity in EMT6 multicellular spheroids suggesting that this metabolic stabilization may allow more efficient diffusion in tumor tissue. The parent compound 2 was selectively toxic to hypoxic cells in KHT tumors in vivo and clearly superior to nitracrine itself (although only at
制备并评估了一系列的硝基氮氧化氮(2;双生物还原性缺氧选择性细胞毒素)的核取代衍生物,以寻找具有较低硝基ac啶还原能力的类似物。用Me或OMe基团在4位和5位上进行的取代不能提供单电子还原电位明显低于相应的单取代衍生物的类似物(对于4-OMe和4-OMe而言,E(1)约为-350 mV 4,5-diOMe化合物)。这似乎不是由于cr啶pKa的同时升高,而是由于环中不带有硝基的取代基缺乏直接的电子作用。相反,在硝基环上放置两个OMe基团确实会导致还原电位进一步大幅降低(2,4-diOMe类似物的E(1)为-401 mV)。单取代和二取代的N-氧化物具有比母体硝胺N-氧化物2低得多的细胞毒性,但通常保持非常高的低氧选择性。在缺氧的AA8细胞培养物中,OMe取代的N-氧化物都显示出比2更高的代谢稳定性,并且4-OMe化合物6在EMT6多细胞球体中的活性得到改善,表明这种代谢稳定作用可以使肿瘤组织