Comparison of polysaccharides from ginkgo biloba leaves with extracellular polysaccharides from endophytic Lysinibacillus sphaericus Ya6

Ginkgo biloba leaf polysaccharide (GBLP) is a biomolecule with various activities such as anti-tumour and anti-inflammatory, but the natural production is low. Extracellular polysaccharide (EPS) was isolated and purified from endophytic Lysinibacillus sphaericus Ya6 of Ginkgo biloba. Similarities in chemical structure and biological activity of two polysaccharides were investigated. Results showed that both polysaccharides are acidic polysaccharides containing pyran rings with characteristic absorption peaks for polysaccharides and carboxylates. The molecular weights varied slightly, with 13.20 kDa and 12.08 kDa for EPSYa6 and GBLP, respectively. GC-MS showed that fucose was present only in EPSYa6, and rhamnose and arabinose were higher in GBLP than in EPSYa6. These gaps above may result in higher antioxidant activity of GBLP than EPSYa6, as verified in free radical scavenging capacity. EPSYa6 and GBLP also have antibacterial effects, and EPSYa6 has a wide antibacterial spectrum. Overall, EPSYa6 has similar chemical structure and same biological activity to GBLP, which provides a theoretical basis for subsequent product development. This study can alleviate the shortage of polysaccharide resources caused by the long growth cycle of ginkgo and the complex natural polysaccharide extraction process, which is conducive to the sustainable development of the ecological environment.