Green synthesis of ferulic acid-grafted xylooligosaccharides with enhanced antioxidant and anti-inflammatory activities.

This study successfully developed a novel ferulic acid-grafted xylooligosaccharides (XOS-FA) conjugate using a green and safe esterification reaction. Structural characterization via FTIR and NMR spectroscopy confirmed the successful covalent grafting of ferulic acid onto the XOS backbone via ester bonds, with characteristic peaks observed at 1729 cm-1 (CO stretch) and 1200 cm-1 (CO vibration). Thermogravimetric analysis further indicated enhanced thermal stability of XOS-FA compared to native XOS. The antioxidant performance was significantly improved after grafting; XOS-FA demonstrated strong radical scavenging activities against both DPPH and hydroxyl radicals, with a total antioxidant capacity comparable to free ferulic acid. Biocompatibility assessments revealed an excellent safety profile, including hemolysis rates below 2% and high cell viability exceeding 90% in live/dead staining assays. Moreover, in vitro anti-inflammatory evaluation showed that XOS-FA significantly suppressed the secretion of key pro-inflammatory cytokines (TNF-α and IL-1β) in macrophages, outperforming both XOS and ferulic acid alone. The findings demonstrate that XOS-FA synergistically combines the bioactivities of its components, presenting a promising dual-functional candidate for applications in functional foods, dietary supplements, and biomedical products.