Study On The Functional Supramolecular Assembly Of Calixpyridine Salt With Disodium Methotrexate, Sodium Suramin And Disodium Pyrroloquinoline Quinone

Supramolecular chemistry is a new subject which can intersect with many subjects.Its development cannot be separated from the development of macrocyclic chemistry.In the past few decades,crown ethers,cyclodextrins,calixarenes,cucurbiturils,pillararenes and other macrocyclic compounds have been developed and had a lot of studies,among which water-soluble macrocyclic compounds have attracted extensive attention.Calixpyridinium is a new type of water-soluble macrocyclic compound,which exhibits good bonding potential with anionic guests in aqueous solution.In order to better reveal the host–guest interactions between calixpyridinium and the anionic drugs,we have done the following work:1.We explored the host–guest interaction between calixpyridinium and the anionic anticancer drug methotrexate disodium in water.Unexpectedly,an interesting anisotropic needle-like rather than an ordinary isotropic spherical supramolecular amphiphilic assembly was fabricated by the complexation of calixpyridinium with methotrexate disodium.It is the second anionic guest to be discovered to form the non-spherical supramolecular assembly upon complexation with calixpyridinium.This discovery implies the possibility to construct various topological nanostructures based on the host–guest interactions between calixpyridinium and the anionic drugs in the future.The resulting calixpyridinium–drug assemblies with different morphologies may have the diverse potentials to adjust the efficacies of anionic drugs.2.We constructed an irregular calixpyridinium-suramin sodium supramolecular assembly by the strong host-guest electrostatic interactions.More interestingly,we also prepared a novel regular spherical supramolecular assembly by the hydrogen bonding interactions between suramin sodium and the UV accelerated addition product of deprotonated calixpyridinium in water.The same principle was also applied to construct a UV accelerated regular spherical self-assembly by the addition product of deprotonated calixpyridinium in water.Compared with the complicated and irreversible covalent connection of the light-responsive groups to the building block,which is one of the common means of obtaining light-responsive supramolecular systems,this finding not only provides a smart,facile,and universally applicable method to construct deprotonated calixpyridinium-based light-responsive host-guest systems,but also provides a new idea for the development of other novel light-responsive building blocks.3.We firstly constructed a regular spherical supramolecular assembly by the host-guest interaction between calixpyridinium and the dietary supplement methoxatin disodium salt.Then,in the study of the p H responsiveness of the assembly,we found a simple complex formed by calixpyridinium with methoxatin disodium salt under alkaline conditions.Interestingly,such a conversion from molecular assembly to molecular recognition can be achieved by naked-eye detecting color change in the solution.This finding provides a novel and convenient method to monitor changes in the bonding patterns of supramolecular systems based on calixpyridinium.In addition,this p H-responsive supramolecular assembly could be visualization of drug release in vitro and is expected to be a targeted drug vehicle to transport drug to the human pancreas site.