National Engineering Research Center for Fruits and Vegetables Processing, Beijing 100083, China.
Carbohydr Polym. 2013 Oct 15;98(1):686-91. doi: 10.1016/j.carbpol.2013.06.049. Epub 2013 Jun 29.
Acetylation of pumpkin (Cucurbita pepo, lady godiva variety) polysaccharide using acetic anhydride with pyridines as catalyst under different conditions was conducted to obtain different degrees of acetylation on a laboratory scale. Furthermore, antioxidant activities and cytoprotective effects of pumpkin polysaccharide and its acetylated derivatives were investigated employing various established in vitro systems. Results showed that addition of pyridine as catalyst could increase the degree of substitution, whereas volume of acetic anhydride had little effect. The acetylated polysaccharides in DPPH scavenging radical activity assay, superoxide anion radical activity assay and reducing power assay exhibited higher antioxidant activity than that of unmodified polysaccharide. H2O2-induced oxidative damages on rat thymic lymphocyte were also prevented by pumpkin polysaccharide and its acetylated derivatives and the derivatives presented higher protective effects. On the whole, acetylated polysaccharide showed relevant antioxidant activity both in vitro and in a cell system.
采用乙酸酐和吡啶作为催化剂，在不同条件下对南瓜（Cucurbita pepo，Lady Godiva 品种）多糖进行乙酰化反应，在实验室规模上获得不同程度的乙酰化。此外，还采用各种已建立的体外系统研究了南瓜多糖及其乙酰化衍生物的抗氧化活性和细胞保护作用。结果表明，添加吡啶作为催化剂可以提高取代度，而乙酸酐的用量影响较小。在 DPPH 清除自由基活性测定、超氧阴离子自由基活性测定和还原力测定中，乙酰化多糖的抗氧化活性均高于未修饰的多糖。南瓜多糖及其乙酰化衍生物还可以预防 H2O2 诱导的大鼠胸腺淋巴细胞氧化损伤，并且衍生物表现出更高的保护作用。总的来说，乙酰化多糖在体外和细胞系统中均表现出相关的抗氧化活性。
