A new arabinoxylan from green leaves of Litsea glutinosa (Lauraeae): Structural and biological studies

► Arabinoxylan was isolated from hot water extract of green leaves of Litsea glutinosa. ► Its structure was established by chemical and 2D NMR studies. ► This molecule showed immunomodulating properties. A water soluble new arabinoxylan, isolated through hot water extraction from the green leaves of Litsea glutinosa (Lauraceae) was found to contain xylose and arabinose in a molar ratio of nearly 1:3. On the basis of NMR (1H, 13C, DQF-COSY, TOCSY, NOESY, ROESY, HMBC and DEPT-135), GLC and GLC–MS analyses, the backbone was established as (1→4)-α-d-xylopyranosyl residue, substituted at C-2 with one unit of two adjacently linked (1→3)-α-l-arabinofuranosyl residues and the other one was terminated by β-l-arabinofuranosyl residue. The proposed repeating unit of the molecule was established as: ▪ This molecule showed strong splenocyte, thymocyte, and macrophage activations. The optimum doses of the polysaccharide for splenocyte and thymocyte proliferation were observed at 25μg/mL and 50μg/mL, respectively. An enhanced production of NO was observed at 100μg/mL of the polysaccharide.