Crystal structure of amylose complexes with small ligands

Area of Science:

• Food Science
• Materials Science
• Crystallography

Background:

• Amylose, a polysaccharide, can form inclusion complexes with various small molecules.
• Understanding the structure and properties of these complexes is crucial for applications in food and materials.

Purpose of the Study:

• To prepare and characterize amylose complexes with specific flavor molecules: fenchone, menthone, and geraniol.
• To investigate the influence of different drying procedures on the complex properties.

Main Methods:

• Complex preparation from aqueous solutions.
• Morphological analysis using transmission electron microscopy (TEM).
• Crystal structure determination via wide-angle X-ray diffraction (WAXD).
• Thermal property assessment using differential scanning calorimetry (DSC).

Main Results:

• Amylose complexes were successfully prepared as lamellar single crystals and polycrystalline powders.
• The crystal structure of these complexes is analogous to V amylose-isopropanol complexes, featuring sixfold helices in orthorhombic unit cells.
• Ligands (flavor molecules) are suggested to occupy the interhelical space.
• Thermoanalysis confirmed the formation of complexes with relatively high crystallinity.
• Drying procedures impacted X-ray diffraction pattern resolution.

Conclusions:

• Amylose forms ordered crystalline structures with fenchone, menthone, and geraniol.
• The observed crystal structure suggests a general packing motif for amylose inclusion complexes.
• The findings provide insights into the molecular interactions governing amylose complexation and crystallinity.