Calixarene and calixresorcarene glycosides: Their synthesis and biological applications

Various approaches that have been carried out for the synthesis of multivalent calixarene and calixresorcarene glycosides (calixsugars) displaying different anomeric linkages and carbohydrate-macrocycle tethers are presented. Because of stability to both acids and bases as well as oxidizing and reducing reagents, also tetrazole ring was considered by Dondoni and Marra a useful system for establishing a robust connection between carbon-linked carbohydrate fragments and a calixarene platform. The issue regarding the glycoside cluster effect has been addressed in various papers. Another important novelty is the study of the interactions of calix-arene-based carbohydrate clusters. Using a few molecular structures constituted of the macrocyclic scaffold decorated with carbohydrate fragments at one rim and four lipophilic alkyl chains at the other rim, a huge number of impressive biological studies have been reported by a Japanese group.