Structural Elucidation and Antioxidant Activities of a Neutral Polysaccharide From Arecanut (Areca catechu L.)

Abstract

A novel neutral polysaccharide designated as PAP1b was isolated from <i>Areca catechu</i> L. by hot water extraction, ethanol precipitation, and column chromatography. PAP1b was mainly composed of mannose, galactose, xylose, and arabinose in a ratio of 4.1:3.3:0.9:1.7, with an average molecular weight of 37.3 kDa. Structural characterization indicated that the backbone of PAP1b appeared to be composed mainly of → 6-β-Man<i>p</i>-(1 →, → 4)-α-Gal<i>p</i>-(1 → and → 3,6)-β-Man<i>p</i>-(1 →) residues with some branches, and terminal of (1 →)-linked-β-Man<i>p</i> residues. The results of bioactivity experiments showed that PAP1b had antioxidant <i>in vitro</i>, esspecially on scavenging DPPH and hydroxyl radicals. Therefore, the polysaccharide from <i>Areca catechu</i> L. could be used as a potential antioxidant in functional food.