2-位或4-位取代吡啶并嘧啶类非经典叶酸拮抗剂的合成及抗肿瘤活性

以非经典叶酸拮抗剂2,4-二氨基-6-(4-甲基苯基)乙基吡啶并3,2-d]嘧啶(wm-5b)及其侧链简化产物2,4-二氨基吡啶并3,2-d]嘧啶为先导化合物, 选取具有抗肿瘤活性的基团, 通过微波法高效合成了2-位或4-位取代吡啶并嘧啶类非经典叶酸拮抗剂, 研究了2-位及4-位取代基对抗肿瘤活性的影响, 为非经典叶酸拮抗剂的设计合成提供了更多的理论依据. 目标化合物的结构均经核磁共振波谱(NMR)和质谱(MS)确证. 生物活性测定结果表明, 所有目标化合物均具有抗肿瘤活性, 其中, 6-(4-甲基苯基)乙基-4-氨基-2-(3-氯-4-氟苯基)氨基吡啶并3,2-d]嘧啶(6b)对HL-60细胞的IC₅₀=(4.09±0.48) μmol/L, 对A549细胞的IC₅₀=(17.99±7.20) μmol/L, 而对HCT116细胞的IC₅₀=(14.52±4.74) μmol/L; 部分目标化合物具有二氢叶酸还原酶抑制活性. 此外, 对部分目标化合物和先导物进行了二氢叶酸还原酶晶体结构的分子对接, 对活性结果和构效关系从分子水平上进行解释.

Synthesis and Anti-tumor Activity Evaluation of a Series of 2- or 4-Substituted Pyrido[3,2-d]pyrimidines as Nonclassical Antifolates †

Using compounds 2,4-diamino-6-(4-methylphenethyl)pyrido 3,2-d] pyrimidine(wm-5b) and 2,4-diaminopyrido 3,2-d] pyrimidine as the lead compounds, a series of 2- or 4-substituted pyrido3,2-d]pyrimidines was synthesized as potential nonclassical antifolates by means of microwave efficiently. Besides, the effects of different substituted positions which provides more theoretical basis for the design and synthesis of nonclassical antifolates can be explored. The target compounds were characterized by ¹H NMR, ¹³C NMR as well as MS. All compounds showed certain anti-tumor activitycompound 6b, the most potent one, has IC₅₀ values of (4.09±0.48) μmol/L against HL-60 cells, IC₅₀ value of (17.99±7.20) μmol/L against A549 cells and IC₅₀ value of (14.52±4.74) μmol/L against HCT116 cells], while some of them exhibited certain inhibition of recombinant human DHFR(rhDHFR). Some compounds and the lead were applied to molecular docking of the crystal structure of dihydrofolate reductase, and the activity results and structure-activity relationship were explained at the molecular level.