【摘要】：持久性有機污染物(Persistent Organic Pollutants, POPs)污染土壤修復的主要難點在于POPs以吸附態(tài)存在于土壤有機質(zhì)中,生物修復效率極低。已有通過羥丙基環(huán)糊精作為增溶劑提高土壤中多環(huán)芳烴生物修復效率的報道,但相關研究多局限于部分較易生物降解的污染物,對疏水及生物毒性更強的POPs還缺乏相關研究。論文的研究目的在于構(gòu)建不同的環(huán)糊精衍生物(Cyclodextrins, CDs)并從中尋找能夠提高土壤中多種POPs分子向微生物的傳遞效率的CDs,最終加快土壤污染物修復效率。本研究首先考察了MOPA、Gaussian兩種軟件的不同優(yōu)化條件、優(yōu)化方法對環(huán)糊精的優(yōu)化情況。經(jīng)過與標準結(jié)構(gòu)的RMSD及能量比較,并結(jié)合相關文獻報道,最終確定采用Gaussian軟件依次進行pm3、hf/6-31g的優(yōu)化方法。并以此為基礎構(gòu)建出所需的CDs及POPs結(jié)構(gòu)。分子對接部分,考察了30種不同結(jié)構(gòu)的CDs與240種POPs的包合效果。以三乙�；�-p-環(huán)糊精和磺丁基-β-環(huán)糊精為代表,其對茚并[1,2,3-cd]芘的結(jié)合能分別為-10.60kcal/mol、-8.87 kcal/mol,而未經(jīng)修飾的p-環(huán)糊精對其結(jié)合能僅為.-7.10 kcal/mol。對接分析表明,在環(huán)糊精的2位與6位羥基修飾物中,2位修飾更有利于提高其包合穩(wěn)定性。其中磺丁基環(huán)糊精與全(2,6-O-甲基)-p-環(huán)糊精在包合效果和水溶性上,均滿足實際要求。動力學計算部分,以CHARMM、CSFF力場為基礎,補充并完成了磺丁基-β-環(huán)糊精的力場制作。在周期性水環(huán)境中考察了p-環(huán)糊精、磺丁基-p-環(huán)糊精對芘的相互作用。相對位置分析發(fā)現(xiàn),磺丁基-β-環(huán)糊精在94.6%的情況下可以穩(wěn)定包合客體分子,而β-環(huán)糊精僅在79.9%的情況下穩(wěn)定包合。最終,從30種CDs中挑選出2-O-磺丁基-β-環(huán)糊精、6-O-磺丁基-p-環(huán)糊精、(2,6-0-甲基)-p-環(huán)糊精三種CDs,其均能與POPs形成穩(wěn)定包合物。同時通過側(cè)鏈對環(huán)糊精包合效果分析顯示,CDs的包合效果不僅與側(cè)鏈結(jié)構(gòu)和其取代位置、取代度有關,還與POPs分子結(jié)構(gòu)存在相關性。因此,采用POPs的在實際生物修復中,應針對污染物組成,制定個性化的環(huán)糊精使用方案。該研究工作,嘗試建立了CDs衍生物結(jié)構(gòu)構(gòu)建方法、編寫了對接結(jié)果批處理腳本,并完成了CDs缺失力場參數(shù)的補充�？梢詾樵u價CDs在促進土壤中POPs污染物生物利用率、批量對接數(shù)據(jù)處理、力場缺失狀態(tài)下的動力學計算等工作提供參考。
[Abstract]:The main difficulty of soil remediation caused by persistent organic pollutant (Persistent Organic Pollutants, POPs) is that POPs is adsorbed in soil organic matter, and the bioremediation efficiency is very low. It has been reported that hydroxypropyl cyclodextrin can improve the bioremediation efficiency of polycyclic aromatic hydrocarbons (PAHs) in soil, but most of the related studies are limited to some easily biodegradable pollutants, but there are few studies on hydrophobic and biotoxic POPs. The purpose of this paper is to construct different cyclodextrin derivatives (Cyclodextrins, CDs) and find out CDs, which can improve the transfer efficiency of many POPs molecules to microorganism in soil and finally accelerate the remediation efficiency of soil pollutants. In this study, the different optimization conditions of MOPA,Gaussian software and the optimization of cyclodextrin were investigated. After comparing with the RMSD and energy of the standard structure, and combining with the related literature reports, the optimization method of pm3,hf/6-31g using Gaussian software is finally determined. On this basis, the required CDs and POPs structures are constructed. In the molecular docking part, the inclusion effects of CDs with 30 different structures and 240 POPs were investigated. As represented by triacetyl-p-cyclodextrin and sulfur-Ding Ji-尾 -cyclodextrin, the binding energy of pyrene to indeno [1O2O3-cd] pyrene is -10.60 kcal / mol -8.87 kcal/mol, respectively, and the binding energy of unmodified pcyclodextrin to pyrene is only .-7.10 kcal/mol.. The results of docking analysis showed that the stability of cyclodextrin inclusion was improved by the modification of 2 and 6 hydroxyl groups of cyclodextrin. The inclusion effect and water solubility of cyclodextrin and total (2o-o-methyl)-p-cyclodextrin met the practical requirements. In the part of dynamics calculation, based on CHARMM,CSFF force field, the force field fabrication of sulfonDing Ji-尾-cyclodextrin is completed. The interaction of p-cyclodextrin and sulfur-Ding Ji -p-cyclodextrin on pyrene was investigated in periodic water environment. The relative position analysis showed that the inclusion guest molecules could be stabilized in 94.6% of sulfo-Ding Ji 尾 -cyclodextrin, but only 79.9% of 尾 -cyclodextrin. Finally, three kinds of CDs, 2-O- sulfur-Ding Ji-尾 -cyclodextrin, (2-O- 6-methyl-methyl) -p-cyclodextrin, were selected from 30 CDs to form stable inclusion complexes with POPs. At the same time, the inclusion effect of CDs on cyclodextrin was analyzed by side chain analysis. The inclusion effect of CDs was not only related to the side chain structure, its substitution position and degree of substitution, but also related to the molecular structure of POPs. Therefore, the application of POPs in bioremediation should aim at the composition of contaminants and develop a personalized scheme of cyclodextrin use. In this work, the structure construction method of CDs derivatives was established, the batch script of docking results was compiled, and the missing force field parameters of CDs were supplemented. It can be used as a reference for evaluating the bioavailability of POPs pollutants in soil, batch docking data processing, dynamics calculation in the absence of force field, and so on.
【學位授予單位】：大連理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：X53

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相關期刊論文 前1條

1 程國玲;李培軍;;石油污染土壤的植物與微生物修復技術(shù)[J];環(huán)境工程學報;2007年06期

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本文編號：2232644