Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, PR China.
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, PR China; Quartermaster Equipment Institute, Academy of Military Sciences PLA China, Beijing 100010, PR China.
Int J Biol Macromol. 2018 Feb;107(Pt B):2611-2619. doi: 10.1016/j.ijbiomac.2017.10.139. Epub 2017 Oct 31.
Two fractions of polysaccharides (MLP-1 and MLP-2) were extracted from the leaves of maca (Lepidium Meyenii Walp.) by water, and purified using DEAE-52 ion exchange resin and sephadex G-200 clumns chromatography. An investigation was carried out for their structural characterization and antioxidant activity in vitro. The results indicated that MLP-1 was mainly composed of ribose, rhamnose, arabinose, xylose, mannose, glucose and galactose, with the molar ratio of 0.12:0.32:1.50:0.32:1.03:1.00:0.93; the MLP-2 was a homopolysaccharide composed of glucose. The molecular weight (Mw) of MLP-1 was 42756Da, and the Mw of MLP-2 was 93541Da. The FT-IR spectra showed the general characteristic absorption peak of maca leaf polysaccharides (MLPs). The evaluation of antioxidant activity revealed that MLP-1 had strong scavenging effects in vitro on hydroxyl, superoxide anion and DPPH radicals, whose EC (mg/mL) was 0.44, 0.21, and 0.82, respectively. Both MLP-1 and MLP-2 presented dose-dependently positive effects on the antioxidant-related parameters. The results suggested that the purified MLP-1 displayed better antioxidant capacities than that of MLP-1, which could be explored as potential antioxidant agents for the complementary medicine or functional foods.
两种多糖（MLP-1 和 MLP-2）从玛卡（Lepidium Meyenii Walp.）的叶子中用水提取，然后使用 DEAE-52 离子交换树脂和葡聚糖 G-200 柱层析进行纯化。对其结构特征和体外抗氧化活性进行了研究。结果表明，MLP-1 主要由核糖、鼠李糖、阿拉伯糖、木糖、甘露糖、葡萄糖和半乳糖组成，摩尔比为 0.12:0.32:1.50:0.32:1.03:1.00:0.93；MLP-2 是由葡萄糖组成的均多糖。MLP-1 的分子量（Mw）为 42756Da，MLP-2 的 Mw 为 93541Da。FT-IR 光谱显示了玛卡叶多糖（MLPs）的一般特征吸收峰。抗氧化活性评价表明，MLP-1 对羟基、超氧阴离子和 DPPH 自由基具有较强的体外清除作用，其 EC（mg/mL）分别为 0.44、0.21 和 0.82。MLP-1 和 MLP-2 对抗氧化相关参数均呈现出剂量依赖性的积极作用。结果表明，纯化的 MLP-1 表现出比 MLP-1 更好的抗氧化能力，可作为补充医学或功能性食品的潜在抗氧化剂进行探索。
