Specific inclusion mode of guest compounds in the amylose complex analyzed by solid state NMR spectroscopy.

The inclusion compound formation between linear amylose of molecular weight 102500 (AS100) and p-aminobenzoic acid (PA) during the sealed-heating process was investigated by powder X-ray diffractometry, infrared spectroscopy and solid state NMR spectroscopy. Sealed-heating of AS100 and PA at 100 degrees C for 6 h provided an inclusion compound with 6(1)-helix structure, while a 7(1)-helix structure was found when sealed-heating was carried out at 150 degrees C for 1 h. The formation of an inclusion compound was not observed when sealed-heating was performed at 50 degrees C for 6 h.