基于丙氨酸的四肽衍生物的合成及自组装行为的研究

发布时间：2018-11-29 09:32

【摘要】：由于手性中心的存在,通常氨基酸衍生物可以自组装形成螺旋的纳米结构。如果只有一个手性中心存在,组装体的手性自然由它控制。肽两亲小分子可以通过分子间的弱相互作用自组装形成有序纳米结构,比如螺旋的纳米纤维、纳米带和管状结构等。肽两亲小分子中存在多个手性中心时,很有必要研究序列中哪个手性中心对组装体的手性有影响。本文以丙氨酸为原料,合成了一系列十三烷基取代的四肽衍生物,建立了丙氨酸手性与自组装体扭转方向之间的关系,并研究了该自组装体在手性纳米材料制备中的应用。其初步结果如下:第一,对于这些丙氨酸四肽衍生物,扫描电镜测试结果表明:当靠近烷基链的两个丙氨酸构型相同时,容易组装形成扭转的纳米带,并且靠近C-端的两个丙氨酸的手性决定了自组装体在纳米尺度上的左右手扭转。圆二色谱和红外光谱测试表明:这种现象的产生与分子间氢键的形成以及羰基的堆积方式有密切的关系。当羰基左手堆积时,自组装体呈现左手扭转。第二,“手性节”结构可能应用于信息存贮领域。在一些半刚性聚合物中可以观察到这种结构。这里,我们以其中的一对对映体去构建“手性节”结构。研究结果表明:它们很难通过共组装形成该结构。共组装体的扭转方向符合“大多数原则”,摩尔比大的四肽分子决定共组装体的扭转方向。最后,以这些四肽衍生物自组装体为模板成功得到了单手扭转的3-氨基苯酚-甲醛树脂纳米带状管。圆二色谱测试结果表明:所得到的产物具有光学活性。其光学活性可能是来源于管壁内表面的手性缺陷。对于某些四肽分子,研究还发现其自组装体与3-氨基苯酚/四肽分子组装体的扭转方向相反。该工作为今后的共组装研究奠定了基础。
[Abstract]:Due to the existence of chiral centers, amino acid derivatives are usually self-assembled to form spiral nanostructures. If there is only one chiral center, the chirality of the assembly is naturally controlled by it. Peptide amphiphilic molecules can self-assemble through weak intermolecular interactions to form ordered nanostructures, such as helical nanofibers, nanobelts and tubular structures. When there are many chiral centers in a peptide amphiphilic molecule, it is necessary to study which chiral center in the sequence has an effect on the chirality of the assembly. In this paper, a series of tridecyl substituted tetrapeptide derivatives were synthesized from alanine, and the relationship between the chirality of alanine and the torsion direction of self-assembly was established, and the application of the self-assembly in the preparation of chiral nanomaterials was studied. The preliminary results are as follows: first, for these alanine tetrapeptide derivatives, SEM results show that when two alanine near the alkyl chain have the same configuration, it is easy to assemble torsional nanobelts. And the chirality of two alanine near the C-terminal determines the left-and right-hand torsion of the self-assembled at nanometer scale. Circular dichroism and IR spectra showed that the formation of intermolecular hydrogen bonds and the accumulation of carbonyl groups were closely related to this phenomenon. When the carbonyl group is stacked in the left hand, the self-assembly presents a left-handed torsion. Second, the chiral section structure may be used in the field of information storage. This structure can be observed in some semi-rigid polymers. Here, we use one of the enantiomers to construct a chiral node structure. The results show that it is difficult for them to form this structure by co-assembly. The reverse direction of the coassembly conforms to the "majority principle", and the reverse direction of the coassembly is determined by the tetrapeptide molecule with large molar ratio. Finally, 3-aminophenol-formaldehyde nanotubes were successfully fabricated by using these tetrapeptide derivatives as template. The results of circular dichroism showed that the obtained products had optical activity. Its optical activity may be due to chiral defects on the inner surface of the tube wall. For some tetrapeptide molecules, the reverse direction of self-assembly is found to be opposite to that of 3-aminophenol / tetrapeptide. This work lays a foundation for future co-assembly research.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O621.1

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