Study On The Supramolecular Interaction Between Calixpyridine Salt And Anionic Drug Molecules Pemetrexed Disodium And Camptothecin Sodium And Its Application

Supramolecular chemistry is a highly interdisciplinary subject with great development prospects.It has received extensive attention in recent years due to its outstanding contributions in materials science,life science and other fields.It is closely related to the development of macrocyclic chemsity.Host–guest chemsity based on macrocyclic host is one of the important methods to construct funtional supramolecular system,and its development has unlimited potential in the supramolecular field.Supramolecular amphiphilic assemblies and supramolecular complexs based on water-soluble macrocyclic host compounds have been widely used in drug controlled release,polychromatic luminescence analytical sensing and other fields.In order to better study the supromolecular interaction between host–guest with calipyridinium as the host and anion drug molecule as the guest,and their application,we carried out the following work:1.The supramolecular assembly constructed by the water-soluble macrocyclic calixpyridinium and the anion drug molecular pemetrexed(Alimta)was studied.The results showed that calixpyridinium and Alimta were complexed to form supramolecular amphiphilic assembly in a ratio of 1:2 through electrotatic and charge-transfer interactions.The supramolecular aggregates show the structure of solid sphere.Meanwhile,they have great time and centrifugal stability.They also exhibit excellent stability in certain concentration of salt solution.Calixpyridinium and Alimta can also form aggregates in Na Cl solution with normal saline concentration.As a result the supramolecular amphiphilic assembly may play a role in human bodies.Further researches revealed that the optimal p H value of calixpyridinium–Alimta aggregates was 5,which is a weak acidic environment suitable for cancer cells.Therefore,the supramolecular aggregates are expected to play a role in improving the performance of anticancer drugs.It is of great significance for the exploration of supramocular interactions between calixpyridinium and anion drugs.2.We investigated the supramolecular interactions between calixpyridinium and anion guest camptothecin sodium(CPT-Na~+).The host–guest interactions were studied by various testing methods,such as ~1H NMR,fourier transform infrared(FT-IR),X-ray photoelectron spectroscopy(XPS),and computational simulation,which confirmed calixpyridinium and CPT-Na~+form supramolecular complex through electrostatic and charge transfer interactions.On the basis,the p H responses of calixpyridinium and CPT-Na~+were investigated.Studies have shown that the methylene bridges of calixpyridinium were found to be deprotonated under alkaline conditions,which improved conjugated degree of calixpyridinium and generated deprotonated-calixpyridinium(depro-calixpyridinium).Color of the calixpyridinium solution changed from colorless to yellow,accompanied by the appearance of yellow-green fluorescence.The discovery of the fluorescent macrocyclic skeleton will be applied in many fields and provides a new idea for exploiting other fluoresccent macrocyclic skeletons.Here,depro-calixpyridinium with yellow-green fluorescence and CPT-Na~+with blue fluorescence are complexd to form supromolecular complex with near white-light fluorescence emission which is(0.28,0.38)in CIE 1931chromaticity diagram,achieving multicolor luminescence.3.We investigated the alteration of fluorescence of calixpyridinium–CPT-Na~+complex in aqueous solution under the neutral condition.The results showed that calixpyridinium–CPT-Na~+complex emitted the blue fluorescence of free CPT-Na~+under p H 6.Depro-calixpyridinium would emit fluorescence gradually with increasing p H and the resulting fluorescent emission of the complex was close to white light,which is(0.23,0.30)in CIE 1931.On the basis of this,calixpyridinium–CPT-Na~+supramolecular complex is expected to be used as a fluorescence sensor to detect alkaline molecules.Here,the fluorescence sensor was applied to arginine(Arg)detection.And the high selective detection of Arg in aqueous solution and real sample urine was realized.The response time is 30 min,the reproducibility is excellent,and the limit of detection is in the same order of magnitude as that reported in the literatures.The construction of this fluorescent sensor provides a new idea for the detection of alkaline compounds.