Compositional and structural characteristics of sulfated polysaccharide from Enteromorpha prolifera

Area of Science:

• Marine natural products chemistry
• Carbohydrate chemistry
• Phycology

Background:

• Enteromorpha prolifera (PE) polysaccharides exhibit potential anticancer, antioxidant, and immunomodulatory activities.
• The precise structural characteristics of PE, crucial for understanding its bioactivities, remain largely undefined.
• Sulfated polysaccharides are known for diverse biological functions, necessitating detailed structural elucidation.

Purpose of the Study:

• To characterize the composition and structure of polysaccharides from Enteromorpha prolifera (PE).
• To elucidate the repeating unit structure of the sulfated polysaccharide backbone.
• To provide a foundation for future research correlating PE structure with its bioactivities.

Main Methods:

• Chemical composition analysis, including IR spectroscopy and HPLC.
• Determination of average molecular weight.
• Enzymatic hydrolysis followed by Mass Spectrometry (MS) and Nuclear Magnetic Resonance (NMR) for structural analysis of carbohydrate residues.

Main Results:

• PE was identified as a sulfated polysaccharide with a high rhamnose content (Rha:GlcUA:Xyl molar ratio of 3.2:1.1:1) and an average molecular weight of 620.3 kDa.
• The backbone structure was determined to consist of repeating units of D-GlcUAp-α-(1→4)-3-sulfate-l-Rha p-β-(1→4)-d-Xyl p-β-(1→4)-3-sulfate-l-Rha p.
• Specific carbohydrate residues rich in sulfated rhamnose were successfully prepared.

Conclusions:

• The study successfully characterized the structural features of a sulfated polysaccharide from Enteromorpha prolifera.
• The identified repeating unit provides critical insights into the molecular architecture of PE.
• These findings are essential for future investigations into the structure-activity relationships of PE.