Characterization of a pectin in fig fruit: Structure and anti-inflammatory activity

Abstract

Fig fruit is widely accepted in warm and tropical regions due to the sweet taste and health benefits. The polysaccharides in fig fruit are responsible for the health benefits. However, information regarding polysaccharide structure remains limited. In this study, the water-soluble polysaccharides (FFP) were extracted from fig fruit with a yield of 15.3 mg/g. Anion exchange chromatography and gel permeation chromatography were used for purification. A leading polysaccharide was purified and characterized as below. The monosaccharide composition of FFP included arabinose (Ara), galactose (Gal), galacturonic acid (GalA) and rhamnose (Rha). The glycosidic linkages were revealed to be L-Ara-(1→, →5)-L-Ara-(1→, →2,4)-L-Rha-(1→, →2)-L-Rha-(1→, →4)-D-Gal-(1→ and D-Gal-(1 → . Nuclear magnetic resonnance (NMR) spectra revealed that FFP had →4)-α-D-GalpA-(1 → 2)-α-L-Rhap-(1→ as backbone. The side chains included Galp-β-D-(1 → 4)-Galp-β-D-(1 → 4)-Galp-β-D-(1 → 4)-Galp-β-D-(1→ and α-L-Araf-(1 → 5)-α-L-Araf-(1 → . They were linked to C-4 of Rhap. FFP inhibited the production of NO, IL-6 and IL-1β levels induced by LPS. IL-6 and IL-1β levels were returned to normal. These information are helpful to understand this functional fruit.