Chemical Composition and Antioxidant Activity of Crude Polysaccharide from Citron ( Sieb. Ex TANAKA) Seed.

The crude polysaccharide (citron seed crude polysaccharide, CSCP) from citron ( Sieb. Ex TANAKA) seed was obtained by water extraction and ethanol precipitation. The results of chemical composition analyses of the CSCP observed that neutral sugar content and uronic acid content were 27.70% and 14.70%, respectively. Monosaccharide composition of the CSCP was as follows in the following order: galacturonic acid+glucuronic acid (14.70 mol%)> arabinose (12.85 mol%)> glucose (4.54 mol%)> galactose (4.32 mol%)> mannose (2.70 mol%)> fucose (1.68 mol%)> rhamnose (1.61 mol%). The total polyphenol contents of the CSCP was 30.42 μg/mL and 86.12 μg/mL at 1 mg/mL and 10 mg/mL, respectively (<0.001). 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity was higher at the concentration of the CSCP 10 mg/mL (47.12%) than that of the CSCP 1 mg/mL (14.02%), (<0.001). The ABTS radical scavenging activity was higher than 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (14.33%) at the same concentration of the CSCP 10 mg/mL (<0.001). Consequently, in this study, the crude polysaccharide from citron seed may be as a novel potential antioxidant.