Structural characterization of a P-selectin and EGFR dual-targeting fucoidan from Sargassum fusiforme

In this study, we obtained fucoidans SFP, SHP, STP, and FVP from Sargassum fusiforme, Sargassum horneri, Sargassum thunbergii, and Fucus vesiculosus, respectively. Chitosan/fucoidan nanoparticles (Cs/F NPs) were prepared using the fucoidans mentioned above. SFP NPs and SHP NPs showed strong binding abilities to P-selectin and epithelial growth factor receptor (EGFR). Given the yields from the alga, SFP was first selected to explore the structural characteristics of the P-selectin and EGFR dual-targeting fucoidan. SFP had an estimated molecular weight of 739 kDa and was mainly composed of galactose (26.57%, mol%) and fucose (66.81%), with minor amounts of mannose (2.54%), glucosamine (0.42%), and glucose (3.66%). Galactose and fucose accounted for the vast majority. Further investigation, including methylation analysis, one- and two-dimensional nuclear magnetic resonance, and mass spectroscopy, was performed to reveal the fine structure of SFP. The results indicated that SFP mainly consisted of -> 3)-alpha-L-Fucp-(1 ->, -> 4)-alpha-L-Fucp-(1 ->, -> 3,4)-alpha-L-Fucp-(1 ->, -> 3)-beta-D-Galp-(1 ->, and minor -> 6)-beta-D-Galp-(1 ->, partially sulfated at the C-4 of -> 3)-alpha-L-Fucp-(1 ->, C-3 of -> 4)-alpha-L-Fucp-(1 ->, C-3 of -> 6)-beta-D-Galp-(1 ->, and C-6 of -> 3)-beta-D-Galp-(1 -> . Sulfated fuco- and galactofuco-segments formed the branches.

Automated summary

In this study, four different fucoidans were obtained from different types of seaweed and used to prepare chitosan/fucoidan nanoparticles. It was found that SFP and SHP exhibited strong binding abilities to P-selectin and EGFR. Further analysis revealed that SFP mainly consisted of galactose and fucose, with sulfated branches.