SYNTHESIS OF 5-METHYL-5-DEAZA NONCLASSICAL ANTIFOLATES AS INHIBITORS OF DIHYDROFOLATE REDUCTASES AND AS POTENTIAL ANTIPNEUMOCYSTIS, ANTITOXOPLASMA, AND ANTITUMOR AGENTS
SYNTHESIS OF 5-METHYL-5-DEAZA NONCLASSICAL ANTIFOLATES AS INHIBITORS OF DIHYDROFOLATE REDUCTASES AND AS POTENTIAL ANTIPNEUMOCYSTIS, ANTITOXOPLASMA, AND ANTITUMOR AGENTS
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DOI：
10.1021/jm00074a026
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发表时间：
1993-10-29
影响因子：
7.3
通讯作者：
KISLIUK, RL
中科院分区：
文献类型：
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作者：
GANGJEE, A;SHI, JF;KISLIUK, RL
合成了一系列 2,4-二氨基-5-甲基-6-(苯胺基甲基)吡啶并[2,3-d]嘧啶 4-9，作为 5-脱氮非经典抗叶酸剂，在 10 位含有三甲氧基、二氯或三氯苯基取代基和 N-H、N-CH3 或 N-CHO。这些化合物被评估为卡氏肺囊虫 (P. carinii)、弓形虫 (T. gondii)、大鼠肝脏 (RL) 和干酪乳杆菌 (L. casei) 的二氢叶酸还原酶 (DHFR) 抑制剂；作为弓形虫和卡氏疟原虫细胞培养物生长的抑制剂；并作为抗肿瘤剂。这些化合物是通过修改经典 5-脱氮叶酸的程序来制备的。 2,4-二氨基-5-甲基-6-[(3',4',5'-三甲氧基-N-甲基苯胺基)甲基]吡啶并[2,3-d]嘧啶 (5a) 对卡氏疟原虫和刚地弓形虫 DHFR 表现出高效力和选择性（与 RL DHFR 相比）。化合物5a是已知的最有效和选择性的弓形虫DHFR非经典叶酸抑制剂之一。 N-10 甲酰基类似物 2,4-二氨基-5-甲基-6-[(N-甲酰基-3',4',5'-三甲氧基苯胺基)甲基]吡啶并-[2,3-d]嘧啶 (6a) 的效力降低，但对弓形虫 DHFR 保持高选择性。相应的氯取代类似物保持效力或降低效力； N-10 取代并未将效力或选择性增加到 3',4',5'-三甲氧基系列中观察到的程度。部分还原B环，得到二氢类似物2,4-二氨基-5-甲基-6-[(N-甲酰基-3',4',5'-三甲氧基苯胺基)甲基]-5,8-二氢吡啶并[2,3-d]嘧啶(7)，其5,6,7,8-四氢吡啶并[2,3-d]嘧啶类似物8，和2,4-二氨基-5-甲基-6-[(3',4',5'-三甲氧基苯胺基)甲基]-5,6,7,8-四氢吡啶并[2,3-d]嘧啶 (9) 导致效力显着降低。在弓形虫细胞培养抑制研究中，2,4-二氨基-5-甲基-6-[(3',4',5'-三甲氧基苯胺基)甲基]吡啶并[2,3-d]嘧啶 (4a)、5a 和 6a 与其 DHFR 抑制效力相比效果较差。针对培养中的卡氏疟原虫细胞，10 μg/mL 的 4a 和 5a 与临床使用的甲氧苄啶/磺胺甲恶唑组合 (50/250 μg/mL) 一样有效。除B环还原类似物7-9外，所有化合物对培养的白血病CCRF-CEM细胞均具有显着的细胞毒性。一般来说，氯取代的类似物比三甲氧基类似物对培养中的多种其他肿瘤细胞更有效。 这些结果得到了美国国家癌症研究所临床前肿瘤筛查项目的证实，其中发现最有效的化合物 2,4-二氨基-5-甲基-6-[(3',4'-二氯苯胺基)甲基]吡啶并[2,3-d]嘧啶 (4b) 可抑制 26 种肿瘤细胞系的生长，IG50 < 1.00 X 10(-8) M。
A series of 2,4-diamino-5-methyl-6-(anilinomethyl)pyrido[2,3-d]pyrimidines 4-9 were synthesized as 5-deaza nonclassical antifolates containing trimethoxy, dichloro-, or trichlorophenyl substitutions and a N-H, N-CH3, or N-CHO at the 10-position. The compounds were evaluated as inhibitors of dihydrofolate reductases (DHFR) from Pneumocystis carinii (P. carinii), Toxoplasma gondii (T. gondii), rat liver (RL), and Lactobacillus casei (L. casei); as inhibitors of T. gondii and P. carinii cell growth in culture; and as antitumor agents. The compounds were prepared by modifications of procedures for classical 5-deaza folates. 2,4-Diamino-5-methyl-6-[(3',4',5'-trimethoxy-N-methylanilino)methyl]pyrido[2,3-d]pyrimidine (5a) exhibited high potency as well as selectivity (compared to RL DHFR) for P. carinii and T. gondii DHFR. Compound 5a is one of the most potent and selective nonclassical folate inhibitors of T. gondii DHFR known. The N-10 formyl analogue 2,4-diamino-5-methyl-6-[(N-formyl-3',4',5'-trimethoxyanilino)methyl]pyrido-[2,3-d]pyrimidine (6a) had decreased potency, but it maintained high selectivity for T. gondii DHFR. The corresponding chloro-substituted analogues maintained potency or had decreased potency; N-10 substitution did not increase potency or selectivity to the extent observed in the 3',4',5'-trimethoxy series. Partial reduction of the B ring to afford the dihydro analogue 2,4-diamino-5-methyl-6-[(N-formyl-3',4',5'-trimethoxyanilino)methyl]-5,8-dihydropyrido[2,3-d]pyrimidine (7), its 5,6,7,8-tetrahydropyrido[2,3-d]pyrimidine analogue 8, and 2,4-diamino-5-methyl-6-[(3',4',5'-trimethoxyanilino)methyl]-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidine (9) resulted in a significant decrease in potency. In T. gondii cell culture inhibitory studies, 2,4-diamino-5-methyl-6-[(3',4',5'-trimethoxyanilino)methyl]pyrido[2,3-d]pyrimidine (4a), 5a, and 6a were less potent compared to their DHFR inhibitory potencies. Against P. carinii cells in culture, 4a and 5a at 10 mug/mL were as effective as the clinically used combination of trimethoprim/sulfamethoxazole (50/250 mug/mL). With the exception of the B ring reduced analogues 7-9, all of the compounds were significantly cytotoxic to leukemia CCRF-CEM cells in culture. The chloro-substituted analogues, in general, were more potent against a variety of other tumor cells in culture than the trimethoxy analogues. These results were corroborated by the preclinical tumor screening program at the National Cancer Institute where the most potent compound 2,4-diamino-5-methyl-6-[(3',4'-dichloroanilino)methyl]pyrido[2,3-d]pyrimidine (4b) was found to inhibit the growth of 26 tumor cell lines at an IG50 < 1.00 X 10(-8) M.