Concise assembly of linear alpha(1-->6)-linked octamannan fluorescent probe

Area of Science:

• Carbohydrate Chemistry
• Organic Synthesis
• Glycobiology

Background:

• Linear alpha(1-->6)-linked mannans are significant in biological systems.
• Fluorescent labeling of complex carbohydrates is crucial for tracking and studying their functions.
• Efficient synthesis of well-defined oligosaccharides remains a challenge.

Purpose of the Study:

• To develop a robust synthetic route for a fluorescently labeled linear alpha(1-->6)-linked octamannan.
• To utilize glycosyl fluoride donors and thioglycosyl acceptors for efficient glycosidic bond formation.
• To create a dansylated octamannan for potential use in biological studies.

Main Methods:

• Employing a selective and convergent two-stage activation strategy for glycosylation.
• Executing three glycosylation steps to construct di-, tetra-, and octamannosyl thioglycosides.
• Coupling a dansyl group to an azidoethyl octamannosyl thioglycoside intermediate.
• Performing global deprotection to yield the final dansylated octamannan.

Main Results:

• Successful synthesis of di-, tetra-, and octamannosyl thioglycosides with excellent yields.
• Efficient coupling of the dansyl fluorescent label to the octamannan core.
• Isolation of the desired dansylated homo-linear alpha(1-->6)-linked octamannan after deprotection.

Conclusions:

• A reliable method for synthesizing fluorescently labeled linear alpha(1-->6)-linked octamannan was established.
• The employed glycosylation strategy proved effective for constructing complex mannan structures.
• The synthesized dansylated octamannan is a valuable tool for future glycobiology research.