Host–guest complex formation in cyclotrikis-(1→6)-[α- d-glucopyranosyl-(1→4)-β- d-glucopyranosyl]

The possibility that cyclotrikis-(1→6)-[α- d-glucopyranosyl-(1→4)-β- d-glucopyranosyl] (CGM6) forms inclusion complexes, like cycloamyloses (cyclodextrins), was investigated by means of electrospray mass spectrometry and fluorescence spectroscopy. The complexing ability of both 1-anilinonaphthalene-8-sulfonate (ANS) and 2- p-toluidinylnaphthalene-6-sulfonate (TNS), which were already used with cyclodextrins, was investigated. The former showed very little or no tendency to be complexed by CGM6, while the latter produced detectable adducts with CGM6. Fixed 90° angle light scattering experiments supported the findings obtained by molecular modelling calculations, which indicated a polar character for the CGM6 internal cavity. CGM6–TNS complexes were probably formed throughout interaction of the polar regions of the two molecules.