铰接十四元瓜环对生物小分子的识别性能研究

发布时间：2018-07-20 12:49

【摘要】：瓜环作为超分子主客体化学中的一种主体化合物,是一类由苷脲单元通过亚甲基桥联起来的大环笼状化合物,其具有疏水性的空腔和亲水性的端口,可以在溶液中选择性地结合多种有机、无机及生物分子形成主-客体包结配合物或自组装超分子实体。铰接十四元瓜环(tQ[14])是由十四个苷脲单元通过26个亚甲基桥联后形成的长带一端旋转180°后由2个亚甲基桥联关环而成,其结构类似阿拉伯数字“8”的形状。与普通瓜环(Q[5-8,10])相比,tQ[14]的溶解性能独特,它既能溶于水,又能溶于二甲亚砜,而且从其结构可以看出,tQ[14]有一个中心空腔和两个边沿空腔,tQ[14]具有目前已报道的所有瓜环中都不具有的特殊结构。本论文以tQ[14]为主体,选择诸如氨基酸、生物染料等生物小分子,以主客体识别作用为基础,研究了tQ[14]对上述生物小分子的识别机制及作用规律。在此基础上,构筑了tQ[14]/生物染料超分子荧光探针,并研究了其对金属离子、农药等的分析检测性能,为铰接十四元瓜环的进一步应用提供思路和方法,主要研究内容及结果如下:研究了tQ[14]对20种L-氨基酸的超分子识别作用,探讨了主客体复合物的作用模式、结构特征及相关热力学参数等信息。研究结果发现在20种L-氨基酸中,tQ[14]对两种碱性氨基酸(Lys,Arg)呈现了特殊的识别作用,Lys和Arg要么直接进入tQ[14]的中心空腔,或者位于tQ[14]的两个边沿空腔形成了特殊的主客体复合物。其作用驱动力可能是由于瓜环羰基端口与氨基酸的离子偶极作用及氨基酸侧链与瓜环空腔的疏水作用引起的。对于Phe,Tyr,Trp,His,Met,Cys来说,氨基酸上的侧链基团进入了tQ[14]的中心空腔,其相互作用主要来自于氨基酸侧链与瓜环空腔的疏水作用。而对剩余的12种氨基酸,一组为Pro,Val,Ala,Leu,Ile,Gly,另一组为Asn,Asp,Glu,Gln,Thr,Ser,对于Pro,Val,Ala,Leu,Ile,Gly来说,它们的侧链基团也进入tQ[14]的中心空腔,但与t Q[14]的作用较弱,但是tQ[14]与Asn,Asp,Glu,Gln,Thr,Ser几乎没有作用,因此tQ[14]与20种L-氨基酸主客体的作用模式由于侧链基团的不同而显示出较大的差异,呈现出特殊的识别性能。研究了tQ[14]与花菁染料噻唑橙(Thiazole orange,TO)的超分子相互作用。由于tQ[14]特殊的柔性结构特征及瓜环端口密度高的羰基氧,在以TO作用时存在着较复杂的作用模式;(1)TO的噻唑环部分可进入tQ[14]的空腔;(2)TO二聚体可位于tQ[14]的端口;(3)随着瓜环浓度的增加,还存在着瓜环的外壁与TO的芳香环之间的外壁作用,因此t Q[14]与TO形成了结构新颖的超分子组装体,而且tQ[14]可使TO的荧光强度得到极大的增强。根据tQ[14]能使TO荧光增强这一现象构筑了不同比例的tQ[14]/TO超分子荧光探针。研究发现在不同的介质条件下,不同比例的tQ[14]/TO超分子荧光探针对金属离子有着不同的响应,如Hg~(2+)在水溶液中使t Q[14]/TO(2:1)荧光强度增强;Ba~(2+)在HCl水溶液中使tQ[14]/TO(2:1,pH=2)的荧光发生猝灭;Pb~(2+)可在HCl水溶液使tQ[14]/TO荧光(15:1,pH=2)发生猝灭。因此tQ[14]/TO超分子荧光探针可实现对上述重金属离子的检测。分析检测性能研究表明:在一定浓度范围内,金属离子的浓度与探针的荧光强度呈良好的线性关系,而且对金属离子的检出限可达10-6~10-7mol/L左右,该结果为金属离子残留的检测提供了理论依据。最后,研究了tQ[14]与苯乙烯基类染料2-[4-(二甲氨基)苯乙烯基]-1-甲基吡啶碘(DSMI)、反-4-[4-(二甲氨基)苯乙烯基]-1-甲基吡啶碘(t-DSMI)及常用除草剂百草枯之间的超分子相互作用。研究结果表明:tQ[14]在pH=6的缓冲溶液中能使DSMI及t-DSMI的荧光强度发生增敏,并形成1∶1主客体复合物,当调节体系的酸度使其pH=2时,体系的荧光发生猝灭,而且在不同的酸度下,主客体的作用模式也有着较大的区别,即由端口作用向空腔作用发生转变;根据tQ[14]在pH=6的缓冲溶液中使染料的荧光强度发生增敏这一现象构筑了瓜环/染料超分子荧光探针,并对农药进行了检测,结果显示出探针对百草枯有着良好的选择性,且线性关系好,检出限达10-8mol/L左右。
[Abstract]:As a main body compound in the supramolecular host and guest chemistry, the melon ring is a class of large caged compounds linked by the methylene bridge through the methylene bridge. It has a hydrophobic cavity and a hydrophilic port. It can selectively combine a variety of organic, inorganic and biological molecules to form host guest inclusion complexes or self groups in the solution. The articulated fourteen element melon ring (tQ[14]) is made up of 2 Ya Jiaji bridging rings which are rotated by fourteen anoside cells through 26 Ya Jiaji bridging and 180 degrees. The structure is similar to the shape of the Arabia digital "8". Compared with the common melon ring (Q[5-8,10]), the solubility of tQ[14] is unique and it can be dissolved in both Water can also be dissolved in two methyl sulfoxide, and it can be seen from its structure that tQ[14] has a central cavity and two border cavities. TQ[14] has a special structure that has not been reported in all the cucurbit rings reported at present. This paper, based on tQ[14], selects small molecules such as amino acids, biological dyes and other biological molecules, based on the recognition of host and guest. The identification mechanism and action law of tQ[14] on the above biological small molecules were studied. On this basis, the tQ[14]/ bio dye supramolecular fluorescence probe was constructed and its analysis and detection performance on metal ions and pesticides were studied. The main research contents and results are as follows: the main research contents and results are as follows: The supramolecular recognition of 20 kinds of L- amino acids by tQ[14] was investigated. The modes of action, structural characteristics and related thermodynamic parameters of the host and guest complexes were discussed. The results showed that in the 20 kinds of L- amino acids, tQ[14] had a special recognition effect on two basic amino acids (Lys, Arg), and Lys and Arg either entered the center of tQ[14] directly. The cavity, or a special host and guest complex formed at the two edge cavity of the tQ[14], may be caused by the ionic dipole effect of the carbonyl port of the melon ring and the amino acid ion dipole and the hydrophobicity of the amino acid side chain and the cavity of the melon ring. For Phe, Tyr, Trp, His, Met, Cys, the side chain group on the amino acid enters tQ. The interaction of [14]'s central cavity mainly comes from the hydrophobicity of the amino acid side chain and the cavity of the melon ring. For the remaining 12 kinds of amino acids, one is Pro, Val, Ala, Leu, Ile, Gly, and the other group is the central cavity of the side chain. The effect is weak, but tQ[14] has little effect on Asn, Asp, Glu, Gln, Thr, Ser, so the mode of action of tQ[14] and the main object of 20 L- amino acids shows a great difference because of the different side chain groups, and presents a special recognition performance. The supramolecular interaction between tQ[14] and the cyanine dye thiazole orange (Thiazole orange) is studied. The specific flexible structure of tQ[14] and the carbonyl oxygen of the high density of the melon ring port have a more complex mode of action in the action of TO; (1) the thiazole ring part of TO can enter the cavity of the tQ[14]; (2) the TO two polymer can be located at the port of tQ[14]; (3) as the concentration of the melon ring increases, there is also the outer wall of the melon ring and the aromatic ring of TO. The wall action, so t Q[14] and TO formed a novel structure of supramolecular assembly, and tQ[14] can greatly enhance the fluorescence intensity of TO. According to the phenomenon that tQ[14] can enhance the TO fluorescence enhancement, a different proportion of tQ[14]/TO supramolecular fluorescence probes have been constructed. The study found that the tQ[14]/TO superfraction of different proportions in different medium conditions. The fluorescent probes have different responses to metal ions, such as Hg~ (2+) enhancing the fluorescence intensity of t Q[14]/TO (2:1) in aqueous solution; Ba~ (2+) quenches the fluorescence of tQ[14]/TO (2:1, pH=2) in the aqueous solution of HCl. The analysis of the analysis and detection performance of the above heavy metal ions shows that the concentration of metal ions has a good linear relationship with the fluorescence intensity of the probe in a certain concentration range, and the detection limit of metal ions can be about 10-6~10-7mol/L. The result provides a theoretical basis for the detection of metal ion residues. Finally, the study of tQ[14 The supramolecular interaction between 2-[4- (two methylamino) styrene based]-1- methyl pyridine iodine (DSMI), anti -4-[4- (two methylamino)]-1- methylpyridine iodide (t-DSMI) and common herbicide paraquat. The results show that the fluorescence intensity of DSMI and t-DSMI can be sensitized by tQ[14] in the buffer solution of pH=6. The 1: 1 host and guest complex is formed. When the acidity of the regulating system makes it pH=2, the fluorescence of the system quenches, and the mode of action of the host and the object varies greatly under different acidity, that is, the effect of the port action to the cavity is changed, and the fluorescence intensity of the dye is sensitized by the buffer solution of the pH=6 in the buffer solution. One phenomenon has constructed the melon ring / dye supramolecular fluorescence probe and tested the pesticides. The results show that the detection of paraquat has good selectivity, and the linear relationship is good, the detection limit is about 10-8mol/L.
【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O641.3;TQ450.1

【相似文献】