Synthesis of bicyclic dipeptide mimetics for the cholecystokinin and opioid receptors
作者:John M. Ndungu、Xuyuan Gu、Dustin E. Gross、James P. Cain、Michael D. Carducci、Victor J. Hruby
DOI:10.1016/j.tetlet.2004.03.146
日期:2004.5
δ-opioid receptors. To constrain the peptide into the biologically active conformation(s), bicyclic dipeptide mimetics for Nle-Gly and homoPhe-Gly were designed and synthesized from β-substituted aspartic acids. Alkylation of L-aspartic acid using lithium bis(trimethylsilyl)amide (LHMDS) in the presence of hexamethylphosphoramide (HMPA) gave β-substituted aspartic acids, with the major product being the
胆囊收缩素C端八肽类似物H-Asp-Tyr-D-Phe-Gly-Trp-(N-Me)-Nle-Asp-Phe-NH 2(SNF 9007)是CCK- B和δ阿片受体。为了将肽限制为生物活性构象,设计了Nle-Gly和homoPhe-Gly的双环二肽模拟物,并由β-取代的天冬氨酸合成。在六甲基磷酰胺(HMPA)存在下,使用双(三甲基甲硅烷基)酰胺锂(LHMDS)将L-天冬氨酸烷基化,得到β-取代的天冬氨酸,主要产物为(2 S,3 R)异构体。Nle-Gly双环二肽模拟物的其他异构体是通过Kazmaier-Claisen重排反应获得的。通过X射线和NMR确定双环二肽模拟物的立体化学。