Laminarin acetyl esters: Synthesis, conformational analysis and anti-viral effects

Area of Science:

• Carbohydrate Chemistry
• Biochemistry
• Antiviral Research

Background:

• Polysaccharide chemical modification is key for new applications and understanding structure-property links.
• Laminarin, a polysaccharide, has potential biological activities that can be modulated through chemical derivatization.

Purpose of the Study:

• To synthesize and characterize acetylated laminarin derivatives.
• To evaluate the antiviral activities of these derivatives against Herpes Simplex Virus type 1 (HSV-1).
• To investigate the structure-property relationships influenced by acetylation.

Main Methods:

• Synthesis of laminarin acetyl derivatives.
• Characterization using FT-IR, H1 NMR, AFM, UV-vis spectroscopy, and ICD-CR assay.
• Antiviral activity assessment via viral plaque assay and analysis of virus-associated DNA/protein changes.

Main Results:

• Acetylation induced a conformational transition of laminarin from a triple helix to a single helix.
• The degree of substitution controlled the extent of this conformational transition.
• The single helical acetylated laminarins were stable in neutral aqueous solutions and non-cytotoxic.
• Antiviral activity against HSV-1 was reduced in the acetylated derivatives compared to native laminarin.

Conclusions:

• Acetylation significantly alters laminarin's secondary structure, affecting its physical properties.
• While acetylation enhances stability and reduces cytotoxicity, it diminishes the antiviral efficacy against HSV-1.
• Further research may explore other modifications to retain or enhance antiviral activity.