Supramolecular Functional Materials Based On Macrocyclic Molecules And Bioactive Molecules

This dissertation mainly focuses on supramolecular chemistry.A series of cyclodextrin and porphyrin derivatives were synthesized,and the supramolecular functional materials such as vesicles,fluorescent probe,nanoribbons etc.were constructed,drug delivery,biomimetic catalysis,probe detection and supramolecular self-assembly of those functional materials were further studied.This dissertation has five parts as below:1.IntroductionThe concept of supramolecular chemistry,non-covalent bonds involve in supramolecular chemistry,the development.history,physical and chemical properties and applications of cyclodextrin,the development history,physical and chemical properties and applications of cucurbituril,applications of supramolecular vesicles,fluorescent probe and gel,were introduced.2.Supramolecular vesicles based on cyclodextrin and its derivatives for drug deliveryP-cyclodextrin can form inclusion complex with a series of hydrophobic guest molecules and then further self-assemble into supramolecular vesicles,which can be used to deliver anti-tumor drugs.Our lab find that ?-cyclodextrin can form supramolecular amphiphiles with hydrophobic drugs directly and then further self-assemble into supramolecular vesicles.Our supramolecular vesicles can realize double or multiple drug delivery since the cavity of the vesicle can load hydrophilic drug while the wall of the vesicle can load hydrophobic drug.In this chapter,we find that ?-cyclodextrin can form supramolecular vesicles with curcumin.The obtained curcumin vesicles have multiple stimulus responsiveness.The addition of sodium laurate,a-amylase and copper ions,can all destroy the vesicles,inducing release of the loaded drugs.Cyclodextrin derivatives vesicles are also prepared.Mono-(6-dexoy-6-butanediamine)-?-cyclodextrin can form supramolecular vesicles with ftorafur directly.This vesicle can respond to copper ions very well since there are two amino group on cyclodextrin derivative.Ftorafur can be released quickly when copper ions are added into vesicles.Compared to ftorafur,ftorafur vesicles have more better inhibition ability of cancer cell proliferation and cycle against human colon carcinoma cell lines HT-29,which might have the potential application in controlling drug release.Besides,cyclodextrin derivative,mono[6-deoxy-N-butylamino-(N'-1-ferrocenylmethylene)]-?-cyclodextrin(BA-Fc-CD)was firstly synthesized by our group.BA-Fc-CD molecules can self-assemble into supramolecular polymer.Supramolecular polymer can transform to supramolecular vesicles when one equivalent ?-cyclodextrin is added into supramolecular polymer.Amino group can coordinate with copper ions easily while ferrocene group can be oxidized easily,hence,the obtained vesicles have good responsiveness to copper ions and hydrogen peroxide.3.Supramolecular system of ?-cyclodextrin and biomimetic catalysisIn traditional organic chemistry,many methods like extra reagents,harsh conditions and complicated steps are applied to get high selectivity and velocity.Besides,toxic and harmful organic solvents are often used as reaction medium.Hence,how to make reaction green,how to get high yield under mild condition,become the goal of all chemical scientists.Two amino groups on lysine almost have the same chemical activity under normal conditions,so it needs harsh conditions to make benzyloxycarbonyl react with one amino group of lysine.In this chapter,?-cyclodextrin is added into this reaction to detect its effect on this reaction.It's amazing that ?-cyclodextrin can catalyze this reaction perfectly.High regio-(>99%)and enantiomeric excess(ee>99%)product can be achieved in short times within 10 minutes under mild conditions.This green catalysis reaction has great practical value,paving new avenue for biomimetic catalysis of P-cyclodextrin.4.Cucurbituril supramolecular fluorescent probe and detection of paraquatParaquat can kill different kinds of weeds effectively,meanwhile,toxic paraquat poses a serious threat to human and animal life safety.Hence,it's necessary to prepare rapid and efficient detection probe of paraquat.In this chapter,two porphyrin derivatives,PCl4 and PMe4Cl8,were synthesized.One equivalent PCl4 can form supramolecular fluorescent probe with four equivalent Cucurbit[7]uril,which can be used to detect paraquat in water effectively.The florescence of PCl4 molecule almost quenches in aqueous solution since aggregation-caused quenching effect.When four equivalent cucurbit[7]uril are added into PCl4 aqueous solution,cucurbit[7]uril can form complex with PCl4 molecule,limiting the rotation of PCl4 molecule,reducing the nonradiative transition of PCl4 molecule,enhancing the system's fluorescence.Compared to PCl4 molecule,paraquat has higher binding constant with cucurbit[7]uril,so PCl4 molecule will be replaced by paraquat when paraquat is added into this supramolecular fluorescent probe,reducing system's fluorescence again.Hence,this probe can be used to detect paraquat according to the fluorescence change.PCl4/cucurbit[7]uril supramolecular fluorescent probe can detect paraquat quickly,meanwhile this probe's fluorescence change can be observed by naked eyes,implying the probe's potential application in paraquat detection.Although PMe4Cl8 molecule can also form complex with cucurbit[7]uril,PMe4Cl8/cucurbit[7]uril doesn't have any fluorescence since there are 8 positive charges on PMe4Cl8 molecule.Hence,PMe4Cl8 molecule can't be used to construct fluorescent-probe.5.Novel supramolecular self-assembly system of bioactive molecules Cholesterol can self-assemble in blood vessel,making risks of myocardial infarction or stroke.Therefore,it's very significant to study the self-assembly behavior of bioactive molecules.In this chapter,we tried to study self-assembly behaviors of anti-tumor drug camptothecin and preservative sodium benzoate.Camptothecin molecule can self-assemble into nanoribbon if water is added into camptothecin DMSO solution.Nanoribbon will disappear if the pH value changes to alkaline.The terminal ring of camptothecin can be converted reversibly between the carboxylate form in basic environment and the lactone form in acidic environment.The lactone form of camptothecin is water insoluble,so it's easy to self-assemble in water.Meanwhile,the carboxylate form of camptothecin is water soluble,so its self-aggregate will disappear.Besides,sodium benzoate can self-assemble into vesicles under low concentration while can self-assemble into gel under high concentration.The obtained gel can respond to metal ions and acid.The gel will collapse when copper,zinc and calcium ions or hydrochloric acid are added into gel.It's interesting gel will form again if sodium hydroxide was added into precipitate with hydrochloric acid.Finally,micro-aggregates can be found in sodium benzoate calf serum.Hence,the safety of sodium benzoate should cause our attention since sodium benzoate as a preservative is widely used in food industry.