Optimized two-step flash chromatography method for large-scale isolation of linusorb and its antioxidant capacity...

Area of Science:

• Natural Product Chemistry
• Biochemistry
• Chromatography

Background:

• Linusorbs (LOs), also known as cyclolinopeptides, are a class of cyclic peptides found in flaxseed.
• Understanding their purification and antioxidant mechanisms is crucial for potential applications.

Purpose of the Study:

• To develop a novel, scalable purification method for linusorbs using flash chromatography.
• To investigate the structure-activity relationship of linusorbs concerning their antioxidant capacity.

Main Methods:

• A two-step silica-phenylhexyl flash chromatography strategy was employed for linusorb purification.
• Comparative assessment of the antioxidant capacity of individual linusorbs was conducted.
• Analysis focused on the role of specific amino acid residues (Met, Trp) and structural motifs (Phe-Phe).

Main Results:

• Achieved >90% purity for cyclolinopeptide A, E, and O from an 850 mg load.
• Purified eight additional fractions of various LOs with 60-83% purity.
• Identified Met and Trp residues, along with the Phe-Phe structure, as key contributors to antioxidant activity.

Conclusions:

• The developed flash chromatography method is efficient and scalable for linusorb purification.
• Methionine oxidation impacts antioxidant capacity, while Tryptophan and Phe-Phe structures enhance it.
• Provides valuable insights into linusorb antioxidant mechanisms and purification strategies.