富硒堇叶碎米荠中硒化合物的形态分析与鉴定

该文以富硒堇叶碎米荠为研究对象,通过酶解法提取其中的硒化合物,采用高效液相色谱-电感耦合等离子质谱(HPLC-ICP-MS)定量分析已知的硒化合物;对于未知的硒化合物,将酶解液经3 kDa超滤离心管浓缩除杂、冻干后,用初始流动相复溶,选取Kinetex F5超高效液相五氟苯基柱(100 mm×2.1 mm,2.6μm)...     

四川兴文地区硒的地球化学特征及生物效应

四川兴文土地质量调查显示:兴文县表层土壤中硒质量分数为0.075~2.540 mg/kg,平均值为0.43 mg/kg,富硒土地面积占调查面积53.25%,合计734.75 km^2。全区大米硒质量分数平均值为0.064 mg/kg,硒含量处于较为富足水平。水稻中的硒元素含量与根系土中硒元素呈明显正相关关系。根系土中水溶态硒和离子交换态硒含量高时,土壤容易产出富硒作物。     

气相色谱-质谱法测定富硒酵母中的硒蛋氨酸

建立了气相色谱-质谱（GC-MS）测定富硒酵母中硒蛋氨酸含量的方法。比较了3种从样品中提取硒蛋氨酸方法的效果。样品在三羟甲基氨基甲烷（Tris）缓冲液中酶解24 h后,以丁醇及三氟乙酸酐为衍生化试剂对硒蛋氨酸进行衍生化,采用选择离子模式对衍生物进行GC-MS测定。硒蛋氨酸的回收率为98.5%~103.7%,相对标准偏差为0.9%~2.4%,检出限为0.5 mg/L（S/N=3）。对实际样品进行测定,得到样品中硒蛋氨酸的含量结果。该法简便快速,准确可靠,灵敏度高。     

富硒肝对大鼠GSH-Px、GSH和游离巯基含量的影响

为观察富硒肝和亚硒酸钠对大鼠抗氧化能力的影响。将6只大鼠分为两组:A组用亚硒酸钠[按Se元素计,6μg/(只.d)]灌胃,B组用富硒肝[按Se元素计,6μg/(只.d)]灌胃。于灌胃第0、4、8、12、16、20天内眦采血,测定血浆和血细胞内液中GSH-Px活力以及GSH、游离巯基的含量。结果表明:①给药20 d后A、B组血浆和血细胞内液GSH-Px活力和GSH含量均明显高于灌胃前(P0.05);②A、B组血浆中游离巯基的含量略有增加,而血细胞内含量则大幅降低(P0.05)。结论:经口给予富硒肝可诱导大鼠产生较多的抗氧化物质,增强大鼠的抗氧化能力。其作用可达同剂量亚硒酸钠水平。     

The Main Structural Unit Elucidation and Immunomodulatory Activity In Vitro of a Selenium-Enriched Polysaccharide Produced by Pleurotus ostreatus

In recent years, the structure of selenium-enriched polysaccharides and their application in immunomodulation have attracted much attention. In previous studies, we extracted and purified a novel selenium-enriched Pleurotus ostreatus polysaccharide called Se-POP-21, but its structure and immunomodulatory activity were still unclear. In this study, the main structural unit formula of Se-POP-21 was characterized by methylation analysis and an NMR experiment. The results showed that the backbone of Se-POP-21 was →[2,6)-α-D-Galp-(1→6)-α-D-Galp-(1]₄→2,4)-β-L-Arap-(1→[2,6)-α-D-Galp-(1→6)-α-D-Galp-(1]₄→, branched chain of β-D-Manp-(1→ and β-D-Manp-(1→4)-β-L-Arap-(1→ connected with →2,6)-α-D-Galp-(1→ and →2,4)-β-L-Arap-(1→,respectively, through the O-2 bond. In vitro cell experiments indicated that Se-POP-21 could significantly enhance the proliferation and phagocytosis of RAW264.7 cells, upregulate the expression of costimulatory molecules CD80/CD86, and promote RAW264.7 cells to secrete NO, ROS, TNF-α, IL-1β, and IL-6 by activating the NF-κB protein. The results of this study indicate that Se-POP-21 can effectively activate RAW264.7 cells. Thus, it has the potential to be used in immunomodulatory drugs or functional foods.