5-ARYLTHIO-SUBSTITUTED 2-AMINO-4-OXO-6-METHYLPYRROLO[2,3-D]PYRIMIDINE ANTIFOLATES AS THYMIDYLATE SYNTHASE INHIBITORS AND ANTITUMOR AGENTS
5-ARYLTHIO-SUBSTITUTED 2-AMINO-4-OXO-6-METHYLPYRROLO[2,3-D]PYRIMIDINE ANTIFOLATES AS THYMIDYLATE SYNTHASE INHIBITORS AND ANTITUMOR AGENTS
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DOI：
10.1021/jm00022a015
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发表时间：
1995-10-27
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;DEVRAJ, R;KISLIUK, RL
经典的胸苷酸合成酶（TS）的抗叶酸抑制剂通常需要降低叶酸摄取系统以发挥其抗肿瘤作用。此外，这些类似物通过酶甲酰聚-γ-谷氨酸合成酶（FPGS）进行聚谷氨酰化，这可以防止类似物从细胞中流出，并通常增加其对TS的抑制效力。减少叶酸摄取系统和FPGS功能受损是对此类抗叶酸剂产生耐药性的潜在来源。我们设计并合成了一个经典的6-5环稠合类似物N-[4-[（2-氨基-6-甲基-3，4-二氢-4-氧代-7H-吡咯并[2，3-d]嘧啶-5-基）硫代]-苯甲酰基]-L-谷氨酸（5）和非经典的6-5环稠合类似物2-氨基-6-甲基-5-（4-氧代-7H-吡咯并[2，3-d]嘧啶-5-基）硫代]-苯甲酰基作为TS抑制剂和抗肿瘤剂的（吡啶-4-基硫基）-3，4-二氢-4-氧代-7H-吡咯并[2，3-d]嘧啶（6）。在碘存在下，4-巯基苯甲酸乙酯或4-巯基吡啶的钠盐与2-（新戊酰氨基）-6-甲基-3，4-二氢-4-氧代-7H-吡咯并[2，3-d]嘧啶（17）发生氧化加成反应，合成了类似物5和6。对于5的合成，将从反应中获得的酯脱保护并与L-谷氨酸二乙酯偶联，然后皂化。化合物5是人和细菌TS的有效抑制剂，IC 50值分别为42和21 nM。化合物6对人TS的效力比5低10倍，但对干酪乳杆菌TS的效力比5低4700倍以上。经典类似物5既不是来自CCRF-CEM细胞的人FPGS的底物也不是其抑制剂。化合物5对CCRF-CEM和FaDu肿瘤细胞系以及CCRF-CEM的缺乏FPGA的亚系具有细胞毒性。胸苷保护研究确定TS是5.
Classical antifolate inhibitors of thymidylate synthase (TS) often require the reduced folate uptake system in order to exert their antitumor effects. In addition, these analogues are polyglutamylated via the enzyme folylpoly-gamma-glutamate synthetase (FPGS), which prevents analogue efflux from the cell and usually-increases their inhibitory potency against TS. Impaired function of the reduced folate uptake system and that of FPGS are potential sources of resistance to such antifolates. We designed and synthesized a classical 6-5 ring-fused analogue N-[4-[(2-amino-6-methyl-3,4-dihydro-4-oxo-7H-pyrrolo[2,3-d]pyrimidin-5-yl)thio]- benzoyl]-L-glutamic acid (5) and a nonclassical 6-5 ring-fused analogue 2-amino-6-methyl-5-(pyridin-4-ylthio)-3,4-dihydro-4-oxo-7H-pyrrolo[2,3-d]pyrimidine (6) as TS inhibitors and antitumor agents. The syntheses of analogues 5 and 6 were acheived via the oxidative addition of the sodium salt of ethyl 4-mercaptobenzoate or 4-mercaptopyridine to 2-(pivaloylamino)-6-methyl-3,4-dihydro-4-oxo-7H-pyrrolo[2,3-d]pyrimidine (17) in the presence of iodine. For the synthesis of 5 the ester obtained from the reaction was deprotected and coupled with diethyl L-glutamate followed by saponification. Compound 5 was a potent inhibitor of human and bacterial TS with IC50 values of 42 and 21 nM, respectively. Compound 6 was 10-fold less potent than 5 against human TS but more than 4700-fold less potent than 5 against Lactobacillus casei TS. The classical analogue 5 was neither a substrate nor an inhibitor of human FPGS derived from CCRF-CEM cells. Compound 5 was cytotoxic to CCRF-CEM and FaDu tumor cell lines as well as to an FPGS-deficient subline of CCRF-CEM. Thymidine protection studies established that TS was the primary target of 5.