Monocyclic pteridine analogs. Inhibition of Escherichia coli dihydropteroate synthase by 6-amino-5-nitrosoisocytosines
作者:O. William Lever、Lawrence N. Bell、H. Michael McGuire、Robert Ferone
DOI:10.1021/jm00150a019
日期:1985.12
inhibitors of dihydropteroate synthase from Escherichia coli. A number of 6-(alkylamino)-5-nitrosoisocytosines have in vitro potency equivalent with or superior to that of therapeutically effective sulfonamide inhibitors of the synthase. The sulfonamide drugs are known to compete for the p-aminobenzoic acid binding site of the synthase, and kinetic analysis of inhibition of the synthase by 6-(methyl
在体外评价了多种5,6-二取代的异胞嘧啶衍生物作为来自大肠杆菌的二氢蝶呤合酶的抑制剂。许多6-(烷基氨基)-5-亚硝基异胞嘧啶在体外具有与合成酶的治疗有效磺酰胺抑制剂相当或更高的体外效力。已知磺酰胺类药物会竞争合酶的对氨基苯甲酸结合位点,并通过6-(甲基氨基)-5-亚硝基异胞嘧啶(16; I50 = 1.6 microM)和6- (3-苯氧丙基)氨基类似物(33; I50 = 3.7 microM)表明亚硝基异胞嘧啶抑制剂与蝶啶底物竞争该酶。结构活性研究表明,酶表面对异胞嘧啶6-氨基功能周围区域的空间体积具有较低的耐受性。然而,这种空间不耐受性可以通过具有6-(ω-苯基烷基)氨基取代基的某些类似物实现的正构构相互作用而在很大程度上抵消。例如,6-[((7-苯基庚基)氨基] -5-亚硝基异胞嘧啶(28)与6-甲基氨基化合物16一样有效(I50 = 1.4 microM)抑制剂。尽管5-亚硝基