An Innovative Methodology to Characterize, at the Molecular Scale, Interactions in Polysaccharide Aqueous Solutions.

Area of Science:

• Biophysical Chemistry
• Macromolecular Science
• Solution Chemistry

Background:

• Characterizing molecular interactions in solution, particularly aqueous environments, is challenging due to potential system perturbation.
• Understanding macromolecule and biomacromolecule behavior in solution requires accurate interaction analysis.
• Polysaccharides like xanthan and galactomannan exhibit synergistic interactions in mixtures, necessitating detailed study.

Purpose of the Study:

• To develop and validate an innovative methodology for characterizing molecular interactions in aqueous solutions.
• To elucidate the mechanisms of molecular interactions in polysaccharide mixtures using fluorescence spectrophotometry.
• To investigate dipole-dipole, hydrophobic, and hydrogen bonding interactions in xanthan and galactomannan systems.

Main Methods:

• Utilized fluorescence spectrophotometry as the core analytical technique.
• Employed two molecular fluorescent probes: 8-anilino-1-naphtalenesulfonic acid (ANS) for dipole-dipole and hydrophobic interactions, and 2-benzofuryl-3-hydroxy-4(1H)-quinolone (3HQ-Bf) for hydrogen bonding.
• Studied interactions in xanthan, galactomannan, and their mixtures in aqueous solutions.

Main Results:

• Successfully established a methodology for non-perturbing molecular interaction characterization in liquid media.
• Demonstrated the presence of dipole-dipole interactions, hydrophobic micro-domains, and hydrogen bonding within the studied polysaccharide systems.
• Provided insights into the synergistic interaction mechanisms between xanthan and galactomannan at the molecular level.

Conclusions:

• The developed fluorescence spectrophotometry methodology is effective for characterizing diverse molecular interactions in aqueous solutions.
• The study successfully elucidated the molecular mechanisms underlying the synergistic interactions in xanthan-galactomannan mixtures.
• This approach offers a valuable tool for understanding complex systems in biophysical and macromolecular chemistry.