# Extraction, structural characterization, chemical modification and anti-inflammatory activity of polysaccharides from Ceratocarpus arenarius L

## TL;DR

This paper studies the extraction and modification of polysaccharides from a plant, revealing their anti-inflammatory properties and potential use in food and medicine.

## Contribution

The novel contribution is the structural characterization and chemical modification of Ceratocarpus arenarius polysaccharides and their anti-inflammatory effects.

## Key findings

- Optimal extraction conditions yielded 19.09% crude polysaccharides with high purity.
- Structural modification altered CAP's properties, including solubility and thermal stability.
- CAP derivatives effectively suppressed inflammatory responses in macrophages.

## Abstract

The extraction process for crude polysaccharides from Ceratocarpus arenarius L. was optimized using response surface methodology (RSM). A major polysaccharide fraction with high purity, designated CAP, was isolated from the crude polysaccharides using DEAE-650 M and Sephadex G-75 column chromatography. Its structure was comprehensively characterized using FT-IR, partial acid hydrolysis, peroxide oxidation, Smith degradation, methylation analysis, and NMR analysis. Subsequently, carboxymethylated (CAP-C), acetylated (CAP-A), sulfated (CAP-S), and phosphorylated (CAP-P) derivatives of CAP were prepared. Their structures were characterized using techniques, including HPSEC, GC, UV, FT-IR, Congo red assay, SEM, XRD, and thermal stability analysis. The results of the RSM optimization indicated that the optimal extraction conditions were as follows: time 43 min, ultrasonic power 310 W, liquid–solid ratio 21:1 mL/g, temperature 62 °C. The crude polysaccharide yield obtained under these conditions was 19.09 ± 0.12%. CAP is primarily composed of pyranose rings linked by α-glycosidic bonds. Its backbone primarily consists of →3)-Xylp-(1→, →3)-Galp-(1→, Galp-(1→, and →2,4)-Galp-(1→ glycosidic bonds, while the terminal residues of the side chains are mainly T-Xylp and T-Rhap. Structural modification significantly altered the monosaccharide molar ratio, molecular weight, viscosity, solubility, surface morphology, crystalline characteristics, and thermodynamic properties of CAP and its derivatives. Anti-inflammatory activity studies revealed that different modification methods differentially enhanced the polysaccharide bioactivity. However, all derivatives could effectively suppress LPS-induced inflammatory responses by regulating the production of nitric oxide (NO), prostaglandin E2 (PGE2), interleukin-6 (IL-6), interleukin−1β (IL-1β), and tumor necrosis factor-α (TNF-α). These findings suggest that CAP and its derivatives have potential applications in the functional food and pharmaceutical industries.

Infographic summarizing the extraction and modification of Ceratocarpus arenarius polysaccharides, detailing structural analysis, main chemical components, decreased sugar content and stability, and anti-inflammatory effects in RAW264.7 macrophages without affecting cell viability.