Chemical structure and anti-inflammatory activity of a pectin isolated from sweet potato processing by-products

This study characterized a pectin polysaccharide named HWSP-1 isolated from sweet potato residue. Structural characterization indicated that HWSP-1 might be composed of →4)-α-D-Gal p A-(1 → with methylated Gal p A and →2)-α-L-Rha p -(1 → as the main chain, decorated with some neutral polysaccharide such as Ara-, Gal- and Glu- in the form of branched chains. In the lipopolysaccharide (LPS)-induced cells model, HWSP-1 down-regulated the mRNA expression of IL-1β, TNF-α, and IL-6 via inhibiting the TLR4/NF-κB/NLRP3 pathway. The results indicated that HWSP-1 could serve as a potential functional food ingredient. • Pectin HWSP-1 was isolated from sweet potato residue. • HWSP-1 had an RG-I domain with →4)-α-D-GalpA-(1 → with methylated GalpA (A) and →2)- α-L-Rhap-(1 → (D) as the main chain, decorated with Ara- and Gal- containing side chains at O -4 of Rha p residues. • HWSP-1 mitigated LPS-induced inflammatory damage by inhibiting the TLR4/NF-κB signaling pathway and NLRP3 inflammasome.