目的 从制黄精中提取制黄精粗多糖（Polygonatum cyrtonema polysaccharides，PSP），分离得到制黄精部位多糖，对其结构特征和抗氧化活性进行研究。方法 采用水提醇沉法得到PSP，再经DEAE-Sepharose Fast Flow凝胶色谱柱分离得到制黄精部位多糖，并通过高效凝胶过滤法（high performance gel permeation chromatography，HPGPC）、离子色谱仪和近红外光谱（fourier transform infrared spectroscopy，FT-IR）等方法对多糖的相对分子质量、单糖组成和结构特征进行研究；采用1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picryl-hydrazyl，DPPH）自由基清除法、2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸 [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)，ABTS] 自由基清除法、羟自由基清除法和Fe³⁺还原力测定法对多糖的体外抗氧化活性进行评价。结果 从PSP中分离得到3个制黄精部位多糖（PSP-W、PSP-1和PSP-2），各部位多糖的得率分别为12.55%、4.22%和14.60%。HPGPC测定3个部位多糖相对分子质量分别为4.903×10⁴、1.127×10⁴和2.575×10⁴。PSP-W的主要单糖组成为阿拉伯糖、葡萄糖、半乳糖和甘露糖，PSP-1和PSP-2的主要单糖组成为阿拉伯糖、鼠李糖、半乳糖和半乳糖醛酸。FT-IR光谱表明3个部位多糖含有β-糖苷键且具有吡喃环。抗氧化研究结果表明，PSP-W、PSP-1和PSP-2均具有抗氧化活性，并且存在明显的浓度相关性，其中PSP-1的抗氧化活性最强。结论 从PSP中分离得到3个制黄精部位多糖，均具有一定的抗氧化活性，可作为潜在天然抗氧化剂。为制黄精抗氧化活性机制深入研究以及制黄精多糖相关药物、食品和保健品等开发利用提供研究基础。

Objective The crude polysaccharide (PSP) was extracted from processed Polygonatum cyrtonema and isolated to obtain polysaccharide fractions and their structural characteristics and antioxidant activity were investigated. Methods The crude polysaccharide was extracted by water-extraction and alcohol-precipitation method, then isolated by DEAE-Sepharose Fast Flow gel chromatography column to obtain polysaccharide fractions. The relative molecular weight, monosaccharide composition, and structural characterization of polysaccharide fractions were investigated by HPGPC, ion chromatograph, and FT-IR. DPPH free radicals scavenging, ABTS free radicals scavenging, hydroxyl free radicals scavenging, and Fe³⁺ reducing power assay were used to evaluate their in vitro antioxidant activities. Results Three polysaccharide fractions (PSP-W, PSP-1, and PSP-2) were isolated from PSP, with yields of 12.55%, 4.22%, and 14.6%, respectively. The molecular weights of the three polysaccharide fractions were determined by HPGPC to be 4.903×10⁴, 1.127×10⁴ and 2.575×10⁴, respectively. The monosaccharide composition of PSP-W was arabinose, glucose, galactose, and mannose, and the monosaccharide composition of PSP-1 and PSP-2 was arabinose, galactose, galacturonic acid, and rhamnose. FT-IR spectra showed that the three polysaccharide fractions contained β-glycosidic bonds and had pyran rings. The results of antioxidant studies showed that PSP-W, PSP-1, and PSP-2 all possessed positive antioxidant activity and showed a significant concentration dependence, with PSP-1 having the strongest antioxidant activity. Conclusion Three polysaccharide fractions were isolated from processed P. cyrtonema crude polysaccharides, all of which possessed antioxidant activity and could be used as potential natural antioxidants. This study provides a research basis for the in-depth study of the mechanism of antioxidant activity of processed P. cyrtonema and the development and utilization of processed P. cyrtonema polysaccharide-related drugs, foods and health products.

R284.1

国家重大新药创新专项（2019ZX09735001-004）;国家自然科学基金资助项目（82274078）