Wang G T, Chen Y, Wang S, Gentles R, Sowin T, Kati W, Muchmore S, Giranda V, Stewart K, Sham H, Kempf D, Laver W G
Pharmaceutical Product Division, Abbott Laboratories, Abbott Park, Illinois 60064, USA.
J Med Chem. 2001 Apr 12;44(8):1192-201. doi: 10.1021/jm000468c.
The discovery of (+/-)-(2S,3R,4R)-2-(trifluoroacetamido)methyl-3-amino-1-(N'-ethyl-N'-isopropylcarbamyl)pyrrolidine-4-carboxylic acid (A-192558, 20e) as a potent inhibitor of influenza neuraminidase (NA) is described. Efficient syntheses of two core structures, cis-3-(allyloxycarbonyl)amino-1-(9'-fluorenylmethoxycarbonyl)pyrrolidine-4-carboxylic acid (7) and tert-butyl (+/-)-(2S,3R,4R)-2-aminomethyl-3-bis(tert-butyloxycarbonyl)amino-1-(N'-ethyl-N'-isopropylcarbamyl)pyrrolidine-4-carboxylate (18b), were developed. Starting with these core structures and using available structural information of the NA active site as the guide, analogues were synthesized in both the tri- and tetrasubstituted pyrrolidine series by means of high-throughput parallel synthesis in solid or solution phase for expeditious SAR. These studies accelerated the identification of (+/-)-(2S,3R,4R)-2-(trifluoroacetamido)methyl-3-amino-1-(N-ethyl-N-isopropylcarbamyl)pyrrolidine-4-carboxylate (20e, A-192558) as the most potent NA inhibitor in this series (IC50 = 0.2 microM against NA A and 8 microM against NA B). The X-ray crystallographic structure of A-192558 bound to NA revealed the predicted interaction of the carboxylic group with the positively charged pocket (Arg118, Arg292, Arg371) and interaction of the trifluoroacetamino residue with the hydrophobic pocket (Ile222, Trp178) of the enzyme active site. Surprisingly, the ethyl and isopropyl groups of the urea functionality induced a conformational change of Glu276, turning the Glu276/Glu277 hydrophilic pocket, which normally accommodates the triglycerol side chain of substrate sialic acid, into an induced hydrophobic pocket.
本文描述了(±)-(2S,3R,4R)-2-(三氟乙酰氨基)甲基-3-氨基-1-(N'-乙基-N'-异丙基氨基甲酰基)吡咯烷-4-羧酸(A-192558, 20e)作为流感神经氨酸酶(NA)强效抑制剂的发现过程。开发了两种核心结构的高效合成方法，即顺式-3-(烯丙氧羰基)氨基-1-(9'-芴甲氧羰基)吡咯烷-4-羧酸(7)和叔丁基(±)-(2S,3R,4R)-2-氨甲基-3-双(叔丁氧羰基)氨基-1-(N'-乙基-N'-异丙基氨基甲酰基)吡咯烷-4-羧酸酯(18b)。以这些核心结构为起始原料，并以NA活性位点的现有结构信息为指导，通过固相或溶液相高通量平行合成法，在三取代和四取代吡咯烷系列中合成类似物，以快速进行构效关系研究。这些研究加速了(±)-(2S,3R,4R)-2-(三氟乙酰氨基)甲基-3-氨基-1-(N-乙基-N-异丙基氨基甲酰基)吡咯烷-4-羧酸酯(20e, A-192558)的鉴定，它是该系列中最有效的NA抑制剂(对NA A的IC50 = 0.2 μM，对NA B的IC50 = 8 μM)。A-192558与NA结合的X射线晶体学结构揭示了羧基与带正电荷口袋(Arg118、Arg292、Arg371)的预期相互作用，以及三氟乙酰氨基残基与酶活性位点疏水口袋(Ile222、Trp178)的相互作用。令人惊讶的是，脲官能团的乙基和异丙基诱导了Glu276的构象变化，将通常容纳底物唾液酸甘油三酯侧链的Glu276/Glu277亲水口袋转变为诱导形成的疏水口袋。
