Abstract
Molecular states of salicylic acid (SA) in amylose complexes prepared by sealed-heating were investigated. The powder X-ray diffraction patterns revealed the possibility of the inclusion formation due to the structural change in amylose from a 61-helix, which designates six glucose units per helical turn, to a 71-helix and an 81-helix depending on the concentration of guest molecules. Carbon thirteen solid state cross-polarization and magic angle spinning NMR spectra showed that the molecular states of SA in the 71-helix and 81-helix amylose complexes were similar to those in β-cyclodextrin (CD) and γ-CD inclusion complexes, respectively. It was concluded that one SA molecule was included in the cavity of one unit of amylose helix for the 71-helix amylose complex and two SA molecules for the 81-helix amylose complex.
