Abstract：
Lepidium meyenii Walp., also known as the \"Peruvian national treasure\", is a popular functional food in the daily lives of Peruvian people due to its bioactive with main polysaccharides. However, studies on polysaccharides isolated from Lepidium meyenii were few. Two new highly heterogeneous polysaccharides, MCP-1a and MCP-2b, were isolated and purified from the tuber of Lepidium meyenii. The structure characterization revealed that MCP-1a primarily consisted of D-Glc and had a molecular weight of 6.6 kDa. Its backbone was composed of 1,4,6-α-D-Glc, while branches feature T-α-L-Ara, 1,5-α-L-Ara, and T-α-D-Glc attached to the O-6 positions. MCP-2b was a rare arabinogalactan with a molecular weight of 49.4 kDa. Interestingly, the backbone of MCP-2b was composed of 1,6-β-D-Gal, 1,3,6-β-D-Gal with a few 1,3-β-D-GlcpA-4-OMe units inserted. Side chains of MCP-2b were mainly composed of 1,3-β-D-Gal, T-β-D-Gal, T-α-L-Ara, 1,5-α-L-Ara, with trace amounts of 1,4-β-D-Glc and T-β-D-Glc. The bioactivity assay results revealed that MCP-1a and MCP-2b increased the release of NO, IL-1β, TNF-α, and IL-6 from RAW 264.7 cells at concentrations ranging from 50 μg/mL to 400 μg/mL. Furthermore, MCP-1a and MCP-2b could promote the expression of key transcription factors (IκB-α, p-IκB-α, p65, and p-p65) in the NF-κB pathway, indicating that MCP-1a and MCP-2b had potential immunomodulatory activities.
摘要：
下皮草。,也被称为“秘鲁国宝”，由于其具有主要多糖的生物活性，是秘鲁人民日常生活中受欢迎的功能性食品。然而,对从Meyenii中分离出的多糖的研究很少。两种新的高度异质多糖，MCP-1a和MCP-2b,从甲叶块茎中分离纯化。结构表征表明MCP-1a主要由D-Glc组成，分子量为6.6kDa。它的主链由1,4,6-α-D-Glc组成，而分支以T-α-L-Ara为特征，1,5-α-L-Ara,和T-α-D-Glc连接到O-6位。MCP-2b是一种罕见的阿拉伯半乳聚糖，分子量为49.4kDa。有趣的是,MCP-2b的骨架由1,6-β-D-Gal组成，1,3,6-β-D-Gal,插入少量1,3-β-D-GlcpA-4-OMe单元。MCP-2b的侧链主要由1,3-β-D-Gal,T-β-D-Gal,T-α-L-Ara,1,5-α-L-Ara,含有痕量的1,4-β-D-Glc和T-β-D-Glc。生物活性测定结果表明,MCP-1a和MCP-2b增加了NO的释放,IL-1β,TNF-α,和来自RAW264.7细胞的IL-6，浓度范围为50μg/mL至400μg/mL。此外，MCP-1a和MCP-2b可以促进关键转录因子(IκB-α,p-IκB-α,p65和p-p65）在NF-κB途径中，表明MCP-1a和MCP-2b具有潜在的免疫调节活性。
