Webber S E, Bleckman T M, Attard J, Deal J G, Kathardekar V, Welsh K M, Webber S, Janson C A, Matthews D A, Smith W W
Agouron Pharmaceuticals, Inc., San Diego, California 92121.
J Med Chem. 1993 Mar 19;36(6):733-46. doi: 10.1021/jm00058a010.
The design, synthesis, and biological evaluation of a new class of inhibitors of thymidylate synthase (TS) is described. The molecular design was carried out by a repetitive crystallographic analysis of protein-ligand structures. At the onset of this project, we focused on the folate cofactor binding site of a high-resolution ternary crystal complex of Escherichia coli TS, 5'-fluorodeoxyuridylate (5-FdUMP) and a classical glutamate-containing folic acid analog. A preliminary ternary crystal structure of a novel compound was successfully solved. Upon analysis of this initial complex, further structural elaborations were made, and a series of active 5-(arylthio)quinazolinones was developed. The synthetic strategy was based on the displacement of a halogen at the 5-position of a quinazolinone by various aryl thioanions. The compounds were tested for inhibition of purified E. coli and/or human TS, and were assayed for cytotoxicity against three tumor cell lines in vitro. Significant thymidine protection effects were observed with several of the inhibitors, indicating that TS was the intracellular locus of activity.
本文描述了一类新型胸苷酸合成酶（TS）抑制剂的设计、合成及生物学评价。分子设计通过对蛋白质-配体结构进行重复的晶体学分析来开展。在该项目伊始，我们聚焦于大肠杆菌TS、5'-氟脱氧尿苷酸（5-FdUMP）和一种经典的含谷氨酸叶酸类似物的高分辨率三元晶体复合物的叶酸辅因子结合位点。成功解析了一种新型化合物的初步三元晶体结构。对该初始复合物进行分析后，进一步进行了结构优化，并开发出了一系列活性5-（芳硫基）喹唑啉酮。合成策略基于喹唑啉酮5位上的卤素被各种芳硫阴离子取代。测试了这些化合物对纯化的大肠杆菌和/或人TS的抑制作用，并测定了它们对三种肿瘤细胞系的体外细胞毒性。几种抑制剂显示出显著的胸苷保护作用，表明TS是细胞内的活性位点。
