Intrinsic Folding Proclivities in Cyclic β‐Peptide Building Blocks: Configuration and Heteroatom Effects Analyzed by Conformer‐Selective Spectroscopy and Quantum Chemistry
作者:Mohammad Alauddin、Eric Gloaguen、Valérie Brenner、Benjamin Tardivel、Michel Mons、Anne Zehnacker‐Rentien、Valérie Declerck、David J. Aitken
DOI:10.1002/chem.201501794
日期:2015.11.9
with a trans‐substituted cyclobutane ring has a predilection to form strong C8 hydrogen bonds. Nitrogen‐atom substitution in the ring induces the formation of the hydrazino turn, with a related but distinct hydrogen‐bonding network: the structure is best viewed as a bifurcated C8/C5 bond with the N heteroatom lone electron pair playing a significant acceptor role, which supports recent observations on
这项工作描述了在超声速膨胀之后使用共形体选择性激光光谱法来探测四元环环状β-氨基酸构件的局部折叠倾向。重点放在立体化学作用以及由氮原子取代循环的碳原子引起的结构变化上。获得酰胺A IR光谱,并借助量子化学结构计算对其进行解释。结果提供了证据,表明具有反式的构建基块预取代的环丁烷环易于形成牢固的C8氢键。环中的氮原子取代会诱导肼基肼转向的形成,并具有相关但独特的氢键网络:最好将结构看作是分叉的C8 / C5键,其中N杂原子孤电子对起着重要的受体作用,这支持了最近对溶液中肼基转向结构的观察。出乎意料的是,这项研究表明,尽管比前两种情况都弱,但顺式取代的环丁烷环衍生物也主要增加了C8氢键,这一特征在该结构单元中并不常见。