Isolation, structural elucidation, and immunoregulation properties of an arabinofuranan from the rinds of Garcinia mangostana

In our search for bioactive polysaccharides as immunomodulatory agents, an arabinofuranan (GMP90-1) was purified and characterized from the rinds of Garcinia mangostana L. GMP90-1 (absolute molecular weight: 5.30 × 10³ g/mol) was found to be composed of arabinose, galactose, and rhamnose. The backbone of GMP90-1 was determined as (1→5)-linked α-l-Araf, (1→2,3,5)-linked α-l-Araf, (1→3,5)-linked α-l-Araf, (1→6)-linked β-d-Galp, and (1→2)-linked α-l-Rhap. Conformational analysis revealed GMP90-1 to exist as a rigid rod structure in sodium chloride solution. To explore its potential as immunomodulatory agents, an in vitro cell screening was performed and GMP90-1 was found to significantly enhance the phagocytic uptake of neutral red and improve the secreted level of nitric oxide (NO), interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α) of macrophages. Furthermore, the cellular immunomodulatory activities were confirmed by the in vivo zebrafish experiment, which suggested that GMP90-1 with immunomodulatory effects could be considered as a potential immunomodulatory for immune diseases.

Keywords: 2', 7'-dichlorofluorescein diacetate (PubChem CID: 104913); 3-amino, 4-aminomethyl-2′, 7′-difluorescein diacetate (PubChem CID: 2762646); Conformational analysis; Dimethyl sulfoxide (PubChem CID: 679); GC–MS; Garcinia mangostana L.; Immunoregulation; Macrophages; Methyl iodide (PubChem CID: 6328); NMR; Penicillin (PubChem CID: 2349); Polysaccharide; Sodium borohydride (PubChem CID: 4311764); Sodium chloride (PubChem CID: 5234); Streptomycin (PubChem CID: 19649); Tricaine (PubChem CID: 261501); Trifluoroacetic acid (PubChem CID: 6422); Zebrafish embryo.