Emerging cyclodextrins in the supramolecular realm

Cyclodextrin (CD) is an intracavitary hydrophobic and extracavitary hydrophilic cyclic oligosaccharide consisting of 6,7 or 8 d-glucopyranoglucose units linked by α-1, 4-glycosidic bonds, known as α-, β- and y-cyclodextrin, respectively. This is a typical "cone-tube" molecule, which can bind a specific set of substrates due to its special structure. α -cyclodextrins can easily form stable supramolecular complexes with monocyclic aromatic compounds. β -cyclodextrin can react with anthracene, cholesterol, ferrocene, adamantane, cyclodiene, azo compounds and some of their derivatives. Y-cyclodextrin can form supramolecular complex systems with pyrene, anthracene, phenanthrene and steroids. The inclusion process is non-covalent and reversible, making cyclodextrins one of the most widely used supramolecular host compounds in the field of supramolecular chemistry, including catalysis, self-assembly, molecular recognition, drug transport and other fields. Academician Xu Guangxian, a famous scientist, also pointed out that the supramolecular science of cyclodextrin is less than 11 breakthroughs in the field of chemistry in the 21st century.