黄原胶琥珀酸衍生物的抗氧化活性

Antioxidant Activity of Succinyl Xanthan Oligosaccharides Derivatives

摘要:

黄原胶寡糖与琥珀酸酐反应, 得到3种衍生物XGOSSA-1、XGOSSA-2和XGOSSA-3, 对产物进行FT-IR表征, GPC法测定其相对分子质量分别为7 560、6 400和7 430, 3种衍生物的丙酮酸质量分数分别为4.6%、4.9%和4.9%, 还原糖质量分数分别为20.5%、19.4%和19.0%, 取代度分别为0.18、0.32和0.43。考察3种衍生物对超氧阴离子自由基、羟基自由基、DPPH自由基和过氧化氢的清除活性以及还原能力。3种衍生物的抗氧化强弱顺序为：XGOSSA-1> XGOSSA-2>XGOSSA-3。即当相对分子质量, 还原糖和丙酮酸质量分数相近时, 随着取代度的升高, 抗氧化能力下降。造成这种现象的原因可能是随着取代度增大, 活性羟基数目减少, 导致抗氧化性能降低。

Abstract:

Three succinyl xanthan oligosaccharides(XGOSSA-1, XGOSSA-2, and XGOSSA-3) were prepared. The products were characterized by FT-IR, and the molecular weights of the products determined by GPC method were 7 560, 6 400 and 7 430, respectively. The pyruvic contents of the three derivatives were 4.6%, 4.9% and 4.9% respectively. The reducing sugar contents were 20.5%, 19.4% and 19.0%. The substituting degrees were 0.18, 0.32 and 0.43. Antioxidant activity of the derivatives was evaluated by the scavenging of superoxide anion radical(O2-), hydroxyl radical(·OH), 2, 2-diphenyl-1-picryhydrazyl(DPPH) radical, hydrogen peroxide(H2O2) and determination of reducing power. The order of antioxidant activity was：XGOSMA-1>XGOSMA-2>XGOSMA-3. It indicated that the antioxidant activity of succinyl xanthan oligosaccharides derivatives decreased with the increasing of substituting degrees when they have the similar molecular weight and contents of pyruvic acid and reducing sugar. The results may be related to the fact that the active hydroxyl group decreased with the increasing of the substituting degrees.