Sugar Calixarenes: Preparation of Calix[4]arenes Substituted at the Lower and Upper Rims with O‐Glycosyl Groups

Abstract

A chiral hydrophilic environment is created at either rim of calix[4]arene by the synthesis of glycosyl derivatives such as the water‐soluble tetragalactosyl calixarene 1. This derivative is potentially an attractive synthetic receptor for chiral recognition of polar organic molecules.

Preparation and Characterization of Amphiphilic Calixarene Nanoparticles as Delivery Carriers for Paclitaxel

“…22) Other anionic water-soluble derivatives containing nitro, 23) phosphonic acid, 24) and carboxyl 25) moieties emerged, and the first example of a cationic water-soluble calixarene was reported by Shinkai et al 26) Other cationic calixarenes contain tetraalkylammonium groups and primary amines. [27][28][29] Neutral water-soluble calixarenes have been synthesized with sulfonamides, 30) sugars, 31) and polyoxyethylene. 32) In the development of water-soluble calixarenes, some hydrophilic-modified calixarenes were found to exhibit amphipathy and self-assemble into nano-aggregates in aqueous solutions, which were suitable for the delivery of hydrophobic antitumor drugs.…”

Carbohydrate Wheels: Cucurbituril‐Based Carbohydrate Clusters

“…The CB [6]-based carbohydrate clusters show high selectivity as well as enhanced affinity through multivalent interactions in binding to specific proteins. Moreover, as a result of the CB [6] cavity, they bind molecules to form host-guest complexes, which can be delivered to specific cells that recognize the multivalent carbohydrates.…”

“…[12] In exploring applications of tailor-made CB[n] derivatives, [13] we thought that the rigid structure, unique guest-binding ability, and surface that could be tailored would make CB[n] a useful multivalent scaffold for carbohydrates. Herein, we present novel CB [6]-based carbohydrate clusters, which have multiple carbohydrate moieties attached to the periphery of a CB [6] core.…”

“…Therefore, multiple copies of carbohydrates and proteins participate in binding to enhance the affinity and selectivity, which is known as a glycosidic cluster effect.[2] Based on this concept, a number of multivalent carbohydrate clusters with various scaffolds, [3][4][5][6][7][8][9][10] including polymers, [4] dendrimers, [5] calixarenes, [6] cyclodextrins, [7] nanoparticles, [8] and vesicles, [9] have been synthesized to mimic biological systems, and their multivalent binding abilities toward specific lectins or receptors on the cell surface have been investigated.Cucurbit[n]urils (CB[n], n = 5-10), a family of macrocyclic cavitands comprising n glycoluril units, have a hydrophobic cavity accessible through two identical carbonyl-fringed portals, and form stable host-guest complexes with a wide range of guest molecules.[11] Recently, we reported a method for the direct functionalization of CB[n], which allowed us to introduce multiple substituents at the "equator" of CB [n]. [12] In exploring applications of tailor-made CB[n] derivatives, [13] we thought that the rigid structure, unique guest-binding ability, and surface that could be tailored would make CB[n] a useful multivalent scaffold for carbohydrates.…”

“…CB[6]-based glucose, galactose, and mannose clusters (5, 7, and 9, respectively) were synthesized by photoreaction of (allyloxy) 12 CB [6] [12] and acetylthioglycosides 1, 2, and 3, [7a, 14] respectively, followed by deacetylation (Scheme 1). The carbohydrate clusters were purified by reversed-phase HPLC and fully characterized by various NMR methods, MALDI-TOF mass spectrometry, and elemental analysis (see the Supporting Information).…”