乙酰化海带褐藻多糖硫酸酯的制备及其抗氧化活性研究

Preparation and in vitro antioxidative activity of acetylated fucoidan extracted from Laminaria japonica

目的优选乙酰化海带褐藻多糖硫酸酯的制备方法,并测定不同条件下制备得到的乙酰化衍生物的体外抗氧化活性。方法以甲酰胺为溶剂,乙酸酐为酰化试剂,N-溴代琥珀酰亚胺(NBS)为催化剂,采用正交设计法,考察反应时间、反应温度及酰化剂用量对海带褐藻多糖硫酸酯酰化反应的影响,测定不同条件下乙酰化衍生物的清除超氧阴离子、羟自由基和有机自由基DPPH的能力,及还原能力。结果酰化剂用量和反应温度对海带褐藻多糖硫酸酯乙酰化有显著影响(P<0.05)。不同条件下制备的乙酰化衍生物的清除超氧阴离子、羟自由基和有机自由基DPPH的能力,及还原能力不同。结论NBS作为催化剂对海带褐藻多糖硫酸酯进行乙酰化是可行的,可以代替传统毒性较强的吡啶对海带褐藻多糖硫酸酯的羟基进行乙酰化。乙酰化后多糖的抗氧化活性明显增强,对其进行深入研究有重要意义。

Objective To explore the optimum method for preparation of acetylated fucoidan extracted from Larninaria japonica, and test the antioxidative activity of acetylated fucoidans prepared under different conditions in vitro. Methods Using acetic anhydride as acetylated reagent, N-Bromosuccinimide （NBS） as catalyst, the effects of reaction time, temperature and volume of acetylated reagent were tested by the orthogonal design method. The antioxidative activity of the prepared acetylated fucoidans in vitro was determined, including scavenging activity against superoxide, hydroxyl and DPPH radical and reducing power. Results Volume of acetylated reagent and reaction temperature were the significant factors （P〈0. 05）. Different acetylated fucoidans had different antioxidative activities on scavenging superoxide, hydroxyl and DPPH radical and reducing power. Conclusion Compared with using pyridine as catalyst, NBS was found to be a suitable catalyst for acetylation of hydroxyl groups in fucoidan. The aritioxidative activity of acetylated fucoidan was much stronger than that of natural fucoidan, and other activity of acetylated fucoidan needs further study.