Comparison of the structure and immunomodulatory activity of polysaccharides from fresh and dried longan

Effects of combined ultrasonic and microwave vacuum drying on drying characteristics and physicochemical properties of Tremella fuciformis

“…The results showed that the polysaccharide chains tended to aggregate and the molecular weights increased with the rapid removal of bound water, especially under hot air conditions. Similar results have been reported by Gan et al [8] . The change in the molecular weight of polysaccharides has been attributed to a three-step mechanism of polysaccharide aggregation, β-elimination depolymerization, and reaggregation [36] .…”

“…For example, freeze, hot air, and infrared drying can change the content of neutral sugars, uronic acid, and the protein of bitter gourd polysaccharides [7] . Similarly, Gan et al [8] showed that the drying process may cause changes in monosaccharide conformation, resulting in changes in monosaccharide composition and the proportions of polysaccharides, but did not cause significant changes in the molecular weight and size of the main polysaccharides in longan. In addition, polysaccharides have a variety of functions due to their complex structure and certain molecular weights.…”

Paulownia tomentosa flower polysaccharide as an effective immunopotentiator to enhance immune responses for Newcastle disease vaccine in mice

“…At 14 days after boosting immunization, splenocytes were harvested from the mice (Wang et al, 2016;Kumar et al, 2017;Huang et al,2020;Lu et al,2020;Yu et al, 2020;Gan et al, 2021). Briefly, the mice were sacrificed by cervical dislocation, and the spleens from different groups were aseptically separated.…”

A Novel Polysaccharide Isolated From Fresh Longan (Dimocarpus longan Lour.) Activates Macrophage via TLR2/4-Mediated PI3/AKT and MyD88/TRAF6 Pathways

“…Previous studies demonstrated that the bioactivity of polysaccharide was closely associated with their structural features (Ferreira et al, 2015). The (1→4)-Glc (1→6)-Glc, and (1→6)-Man were found to be the main backbone for many polysaccharides with immunomodulatory activity (Ferreira et al, 2015;Yamabhai et al, 2016;Yan et al, 2018), including longan polysaccharides (Rong et al, 2019;Gan et al, 2021). The linkage characteristics of (1→4)-Glc (1→6)-Glc and (1→6)-Man may contribute to immunoregulatory activity of LP4.…”

“…In early research (Rong et al, 2019), we purified an active polysaccharide (LPD2) from longan, which composed of (1→4)-β-Glc with substituted by acetyl, and (1→6)-β-Man, and induced macrophage activation via the TLR2-and TLR4-mediated MyD88/IRAK4-TRAF6 pathways. The differences in the structure of polysaccharides in these reports may be due to different extraction methods or drying processes (Gan et al, 2021). However, there may be multiple polysaccharides in longan that contribute to the bioactivity of longan.…”