Chemical, physico-chemical and cytotoxicity characterisation of xyloglucan from Guibourtia hymenifolia (Moric.) J. Leonard seeds

A water-soluble polysaccharide was obtained from Guibourtia hymenifolia seeds in a 54.2% yield (w/w). The Glc:Xyl:Gal molar ratio was 3.3:2.3:1. The methylation results and 1D/2D NMR spectra indicated the presence of xyloglucan (XG), the intrinsic viscosity of which was 665 mL/g. The molar mass (Mw), radius of gyration (Rg), hydrodynamic radius (Rh), and ρ (Rg/Rh) of XG were 8.43 × 105 g/mol, 97 nm, 61 nm, and 1.59, respectively, indicating a random coil and flexible conformation that was subsequently confirmed by the Mark–Houwink constant α (0.70). Atomic force microscopy analysis of XG adsorbed on silicon revealed that the chains are an average of 1.25-nm high, 28.9-nm wide and 131-nm long. Furthermore, a cytotoxicity assay indicated a high CC50 value (>3.3 mg/mL). These results suggest that this biopolymer has potential applications in different food technologies and biotechnological processes. AFM topographical image of thin film of xyloglucan from Guibourtia hymenifolia seeds deposited by spin-coating on silicon (2.00 × 2.00 μm). [Display omitted]