关键词: 紫加1号, 嫩茎叶, 多糖, 分离纯化, 单糖组成, 分子量, 抗氧化活性

Abstract: ‘Zijia 1' is a new variety of Acanthopanax senticosus bred by our team, its tender stems and leaves characterized with gray-purple color and sweet taste. This study is aim to isolate and purify the polysaccharides from the tender stems and leaves of ‘Zijia 1', and determine the monosaccharide composition and molecular weight of different fractions obtained after separation, and the antioxidant activity of each fraction was evaluated. The crude Asenticosus polysaccharides(ASPS)were obtained from the tender stems and leaves of ‘Zijia 1' by water extraction and alcohol precipitation, which were then separated and purified by DEAE-Cellulose 52 ion column and Sephadex G-100 gel column to obtain a uniform component. The ion chromatography and gel permeation chromatography-refractive index-multi-angle laser light scattering method was exploited to determine the monosaccharide compositions and molecular weight of the polysaccharides fractions. The hydroxyl radical(·OH), superoxide radical(O₂^-·)and 1,1-diphenyl-2-picrylhydrazyl radical(DPPH)scavenging ability were determined to evaluate the antioxidant of each fraction in vitro. Four polysaccharides ASPA-1-1, ASPA-2-1, ASPA-3-1 and ASPN-1 were isolated and purified from ASPS, with molecular weight of 8.10, 26.15, 0.91, 0.89 kDa, respectively, mainly composed of arabinose, rhamnose, galactose, glucose, xylose, mannose, ribose, galacturonic acid and glucuronic acid in different proportions. The ASPA-1-1, ASPA-2-1, ASPA-3-1 and ASPN-1 from ‘Zijia 1' demonstrated significant scavenging activities on ·OH, O₂^-· and DPPH free radical, the ability of ASPA-2-1 to scavenge ·OH and DPPH is higher than ASPA-1-1, ASPA-3-1 and ASPN-1; ASPA-3-1 has the strongest ability to scavenge O₂^-·. Therefore, the purified polysaccharides from ‘Zijia 1' has obvious antioxidant activity, which provides a scientific theoretical basis for its further utilization.

Key words: ‘Zijia 1', tender stems and leaves, polysaccharides, isolation and purification,monosaccharide compositions, molecular weight, antioxidant activity