McNamara D J, Berman E M, Fry D W, Werbel L M
Department of Chemistry, Parke-Davis Pharmaceutical Research Division, Warner-Lambert Company, Ann Arbor, Michigan 48105.
J Med Chem. 1990 Jul;33(7):2045-51. doi: 10.1021/jm00169a040.
The synthesis and biological activity of two series of nonclassical thymidylate synthase (TS) inhibitors are described. The first is a series of 10-propargyl-5,8-dideazafolic acid derivatives (10a-j) and the second is a series of the analogous 2-desamino derivatives (13a-c,k), both bearing a more lipophilic substituent on the phenyl ring than the CO-glutamate of classical antifolates. Compounds 10a-j were prepared in a straightforward manner, generally by treatment of N-[6-(bromomethyl)-3,4-dihydro-4-oxo-2-quinazolinyl]-2,2-dimethylprop anamide (6) with various phenyl-substituted N-propargylanilines (8), followed by deprotection. Compounds 13a-c,k were prepared similarly from [6-(bromomethyl)-4-oxo-3(4H)-quinazolinyl] methyl 2,2-dimethylpropanoate (11). The compounds were tested for inhibition of purified L1210 TS and for inhibition of L1210 cell growth in vitro. Several of these nonclassical analogues approached the TS inhibitory potency of 10-propargyl-5,8-dideazafolic acid (1, CB3717), a glutamate-containing TS inhibitor. 2-Amino target compounds 10a-j were generally potent inhibitors of L1210 TS, with IC50s within the range of 0.51-11.5 microM, compared to 0.05 microM for 1. The order of potency for phenyl substitution at the 4-position in this series was the following: COCF3 greater than or equal to NO2 greater than or equal to CONH2 greater than or equal to COCH3 greater than SO2NMe2 greater than CN much greater than OCF3 greater than or equal to F. The 2-desamino target compounds 13a-c,k also exhibited significant, although diminished, TS inhibition. Both series were growth inhibitory to cells in tissue culture and this inhibition could be reversed by thymidine alone, indicating that the primary target was TS. None of the compounds was a potent inhibitor of dihydrofolate reductase. These studies indicate that the presence of the glutamate moiety in folate analogues is not an absolute requirement for potent inhibition of TS.
本文描述了两个系列的非经典胸苷酸合成酶（TS）抑制剂的合成及其生物活性。第一个系列是一系列10-炔丙基-5,8-二氮杂叶酸衍生物（10a - j），第二个系列是一系列类似的2-脱氨基衍生物（13a - c，k），这两个系列在苯环上都带有比经典抗叶酸剂的CO-谷氨酸更具亲脂性的取代基。化合物10a - j的制备方法较为直接，一般是用各种苯基取代的N-炔丙基苯胺（8）处理N-[6-(溴甲基)-3,4-二氢-4-氧代-2-喹唑啉基]-2,2-二甲基丙酰胺（6），然后进行脱保护。化合物13a - c，k以类似的方法由[6-(溴甲基)-4-氧代-3(4H)-喹唑啉基]甲基2,2-二甲基丙酸酯（11）制备。测试了这些化合物对纯化的L1210 TS的抑制作用以及对L1210细胞体外生长的抑制作用。这些非经典类似物中的几种接近10-炔丙基-5,8-二氮杂叶酸（1，CB3717，一种含谷氨酸的TS抑制剂）的TS抑制效力。2-氨基目标化合物10a - j通常是L1210 TS的有效抑制剂，IC50在0.51 - 11.5 microM范围内，而1的IC50为0.05 microM。该系列中4-位苯基取代的效力顺序如下：COCF3≥NO2≥CONH2≥COCH3＞SO2NMe2＞CN＞＞OCF3≥F。2-脱氨基目标化合物13a - c，k也表现出显著的TS抑制作用，尽管效力有所降低。两个系列在组织培养中均对细胞有生长抑制作用，且这种抑制作用可单独用胸苷逆转，表明主要靶点是TS。这些化合物均不是二氢叶酸还原酶的有效抑制剂。这些研究表明，叶酸类似物中谷氨酸部分的存在并非有效抑制TS的绝对必要条件。
