L. S. Sandell, P. Luner
Aug 1, 1973
Citations
0
Influential Citations
3
Citations
Journal
Journal of Colloid and Interface Science
Abstract
Abstract The monolayer properties of four acetylated disaccharides of D-glucose have been investigated on concentrated ammonium sulfate substrates. The sugars were characterized by a varying position and anomeric configuration of the glycosidic linkage and included the octaacetates of cellobiose (β −1, 4 linkage), maltose (α −1, 4), gentiobiose (β −1, 6), and isomaltose (α −1, 6). In all cases, the pressure-area isotherms were of the gaseous type at low pressures, reflecting a horizontal orientation at the interface with both glucose residues anchored to the subphase. At higher pressures, rotation about the glycosidic linkage is induced in maltose and isomaltose octaacetates, causing one of the glucose residues to tilt out of the plane of the surface. Pressure—induced conformational folding also occurs in gentiobiose octaacetate, although by a different mechanism which reflects the outstanding flexibility of the β − 1, 6 linkage. The isotherm characteristics of cellobiose octaacetate resemble those of certain rigid polycyclic molecules and indicate that both residues of this sugar tilt laterally as a unit from the horizontal to an upright position. This behavior suggests that the β −1, 4 linkage of cellobiose octaacetate is relatively inflexible.