摘要
以丙氨酰胺基硫脲为β-转角结构模板,于其N-端和C-端分别修饰以噻吩和间碘代苯基,合成折叠短肽分子1,通过吸收光谱、圆二色光谱、核磁共振波谱、X射线单晶衍射、X射线粉末衍射和理论计算等方法,验证了其分子内存在β-转角折叠结构,并探究了其超分子螺旋结构特征.结果揭示了折叠短肽分子1在乙腈中的同质多晶现象:在乙腈中加热冷却后,静置片刻即析出的块状晶体A,为动力学稳态晶体,仅形成一重氢键超分子螺旋结构;静置过夜或缓慢挥发得到的针状晶体B,为热力学稳态晶体,包含氢键和卤键双重超分子螺旋,组成二维螺旋平面,并借助乙腈溶剂参与的氢键作用和尺寸效应,形成稳定的超分子三维结构.晶体B的形成依赖于乙腈溶剂的存在,在其他溶剂如甲醇、三氯甲烷和乙酸乙酯中只形成晶体A.实验结果借助晶体结构直观阐明了动力学、热力学以及溶剂调控下超分子螺旋的结构特征,对超分子螺旋的构筑和调控研究具有借鉴意义.
Using alanine based N-amidothiourea asβ-turn structure template,with thiophene and m-iodobenzene groups respectively equipped at the N-and C-terminus,folded short peptide molecule 1 was synthesized.The intramolecularβ-turn and supramolecular helical structures of 1 were investigated by absorption,circular dichroism and nuclear magnetic resonance spectroscopy,single X-ray diffraction,X-ray powder diffraction,and theoretical calculations.The results reveal that folded short peptide molecule 1 features polymorphism during crystallization in CH 3 CN.Block crystals A of kinetic stability were obtained after heating-cooling and short standing,in which 1D hydrogen-bonded supramolecular helix was formed.Needle-like crystals B of thermodynamic stability were obtained after standing overnight or through slow solvent evaporation,in which both hydrogen-and halogen-bonded supramolecular helices were formed simultaneously,affording 2D helical layers,which were further connected by solvent CH 3 CN molecules through hydrogen bonds and size effect to afford stable 3D superstructure.The solvent CH 3 CN was indispensable to the formation of crystals B,since in other solvents such as MeOH,CHCl 3 or EtOAc,only crystals A were obtained.By virtue of the crystal structures,the regulation mechanism of supramolecular helix through kinetic and thermodynamic pathways and the influence of solvent are illustrated,which is significant to the construction and regulation of supramolecular helix.
作者
汪倩倩
林翔
翁培敏
曹金莲
严小胜
江云宝
WANG Qianqian;LIN Xiang;WENG Peimin;CAO Jinlian;YAN Xiaosheng;JIANG Yunbao(Key Laboratory of Spectrochemical Analysis&Instrumentation,Ministry of Education,Collaborative Innovation Center of Chemistry for Energy Materials,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China;School of Pharmaceutical Sciences,Xiamen University,Xiamen 361102,China)
出处
《厦门大学学报（自然科学版）》
CAS
CSCD
北大核心
2023年第5期824-832,共9页
Journal of Xiamen University：Natural Science
基金
国家自然科学基金(21820102006,91856118,22101240,21435003,21521004)。
关键词
折叠短肽
β-转角
同质多晶
超分子螺旋
卤键
folded short peptide
β-turn
polymorphism
supramolecular helix
halogen bond
作者简介
通信作者:严小胜xshyan@xmu.edu.cn;通信作者:江云宝,ybjiang@xmu.edu.cn。
