Baruah Pranjal K, Sreedevi N K, Gonnade Rajesh, Ravindranathan Sapna, Damodaran Krishnan, Hofmann Hans-Jörg, Sanjayan Gangadhar J
Division of Organic Synthesis, Central Material Characterization Division, and Central NMR Facility, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, India.
J Org Chem. 2007 Jan 19;72(2):636-9. doi: 10.1021/jo062032w.
This note describes the design, synthesis, and conformational studies of a novel hybrid foldamer that adopts a definite compact, three-dimensional structure determined by a combined effect of the special conformational properties of the foldamer constituents. The striking feature of this de novo designed foldamer is its ability to display periodic gamma-turn conformations stabilized by intramolecular hydrogen bonds. Conformational investigations by single-crystal X-ray studies, solution-state NMR, and ab initio MO theory at the HF/6-31G* level strongly support the prevalence of gamma-turn motifs in both the di- and tetrapeptide foldamers, which are presumably stabilized by bifurcated hydrogen bonds in the solid and solution states. The strategy disclosed herein for the construction of hybrid foldamers with periodic gamma-turn motifs has the potential to significantly augment the conformational space available for foldamer design with diverse backbone structures and conformations.
本笔记描述了一种新型杂合折叠体的设计、合成及构象研究。该折叠体具有确定的紧凑三维结构，由折叠体组分特殊的构象性质共同作用决定。这种从头设计的折叠体的显著特征是其能够展现出由分子内氢键稳定的周期性γ-转角构象。通过单晶X射线研究、溶液态核磁共振以及HF/6-31G*水平的从头算分子轨道理论进行的构象研究有力地支持了二肽和四肽折叠体中γ-转角基序的普遍存在，这些基序可能在固态和溶液态中由分叉氢键稳定。本文所揭示的构建具有周期性γ-转角基序的杂合折叠体的策略，有可能显著增加可用于设计具有不同主链结构和构象的折叠体的构象空间。
