Preparation and characterization of novel branched β-cyclodextrins having β-D-galactose residues on the non-reducing terminal of the side chains and their specific interactions with peanut (Arachis hypogaea) agglutinin

Abstract

Six novel branched β-cyclodextrins (βCDs) having β-D-galactose residues on the non-reducing terminal of the sugar side chains, namely 61,64-di-O-(β-D-galactosyl)-βCD (10), 6-O-(β-D-galactosyl)-βCD (11), 61,6 4-di-O-(β-lactosyl)-βCD (14), 6-O-(β-lactosyl)- βCD (15), 61,64-di-O-(4′-O-β-D-galactosyl- β-lactosyl)-βCD (18), and 6-O-(4′-O-β-D-galactosyl-β- lactosyl)-βCD (19), were chemically synthesized using the trichloroacetimidate method. The reaction products were separated by HPLC on an amino column into dibranched and monobranched βCDs. Their structures were confirmed by mass spectrometry (MS) and two-dimensional (2D) NMR spectroscopic analysis. To study the length of the sugar side chains attached to the CD ring, which leads to differences in the functions of the branched CDs, interactions of these compounds with peanut (Arachis hypogaea) agglutinin (PNA) were investigated using an optical biosensor and an inhibition assay based on hemagglutination. The results showed that all branched βCDs interacted with PNA, and the binding affinity was 18>14>10 and 19>15>11 when the derivatives were compared on the basis of side chain length. © 2004 Pharmaceutical Society of Japan.