Structural Modification and Biological Activity of Polysaccharides

Abstract

Natural polysaccharides are macromolecular substances with a wide range of biological activities. The structural modification of polysaccharides by chemical means can enhance their biological activity. This paper reviews the latest research reports on the chemical modification of natural polysaccharides. At present, the modification methods of polysaccharides mainly include sulfation, phosphorylation, carboxymethylation, socialization, methylation and acetylation. The chemical and physical structures of the modified polysaccharides were detected via ultraviolet spectroscopy, FT-IR, high-performance liquid chromatography, ultraviolet spectroscopy, gas chromatography–mass spectrometry, nuclear magnetic resonance and scanning electron microscopy. Modern pharmacological studies have shown that the modified polysaccharide has various biological activities, such as antioxidant, antitumor, immune regulation, antiviral, antibacterial and anticoagulant functions in vitro. This review provides fresh ideas for the research and application of polysaccharide structure modification.

Self-Assembling Sulfated Lactobacillus Exopolysaccharide Nanoparticles as Adjuvants for SARS-CoV-2 Subunit Vaccine Elicit Potent Humoral and Cellular Immune Responses

“…The solubility and bioactivity of polysaccharides can be effectively enhanced by chemical modification. , Modification of polysaccharide sulfation aims to replace the original hydroxyl group of the polysaccharides with a sulfate group to increase the immunoreactivity and electronegativity . Due to the presence of pyran moieties in EPS, we chose the chlorosulfonic acid–pyridine method for sulfation modification of EPS .…”

Research Progress of Polysaccharide-Gold Nanocomplexes in Drug Delivery

“…The negatively charged phosphate groups of phosphorylated polysaccharides can bind with receptors on the surface of immune cells and activate the immune response, resulting in antitumor activity. At the same time, phosphorylated polysaccharides have a higher scavenging capacity for DPPH and superoxide anion [53]. The electrostatic repulsion and spatial resistance of polysaccharides modified by sulfate changed dramatically, which increased the flexibility of polysaccharide chains and improved water solubility, and the The relative molecular mass distribution of polysaccharides, the composition of sugar groups, the type of glycosidic bonding and the way adjacent glycosidic bonds are connected, the presence or absence of branched chains as well as their position and length, and the non-sugar modifications may have a significant effect on their activity, as shown in Figure 2.…”

“…The negatively charged phosphate groups of phosphorylated polysaccharides can bind with receptors on the surface of immune cells and activate the immune response, resulting in antitumor activity. At the same time, phosphorylated polysaccharides have a higher scavenging capacity for DPPH and superoxide anion [ 53 ]. The electrostatic repulsion and spatial resistance of polysaccharides modified by sulfate changed dramatically, which increased the flexibility of polysaccharide chains and improved water solubility, and the sulfated modified yam polysaccharide (S-CYP) could activate macrophages through the MAPK signaling pathway, which showed better immunomodulatory effects than CYP [ 54 ].…”

Carboxymethyl Scleroglucan Synthesized via O-Alkylation Reaction with Different Degrees of Substitution: Rheology and Thermal Stability

“…In general, the modification methods of polysaccharides are classified into six types: sulfation [ 14 ], phosphorylation [ 15 ], carboxymethylation (an O -Alkylation reaction that uses a deprotonated alcohol and an organohalide to form an ether) [ 16 ], methylation [ 17 ], selenization [ 18 ], and acetylation [ 19 ]. The carboxymethylation of polysaccharides has been extensively investigated due to its simplicity.…”