喜树果多糖的理化性质和抗氧化活性研究

Physiochemical Properties and Antioxidant Activity of Camptotheca acuminata Fruit Polysaccharides

本文采用热水浸提、微波辅助、超声波辅助提取喜树果多糖,使用傅里叶变换红外光谱(FTIR)、差示量热扫描仪(DSC)对多糖进行初步的理化性质和组成分析,通过体外试验评价其抗氧化能力。结果表明,微波辅助提取多糖(CAP-M)得率显著高于热水浸提(CAP-H)和超声波辅助提取多糖(CAP-U),为7.25%;初步的理化性质和组成分析显示三种多糖差异不显著,且均为含有少量蛋白的酸性多糖;在羟基自由基和DPPH自由基清除能力中CAP-H活性均高于CAP-M和CAP-U,IC_(50)值为0.775 mg/mL和0.648 mg/mL,总还原力也显著高于CAP-M和CAP-U;而在铁离子螯合能力中CAP-M表现最佳,IC_(50)值为1.745 mg/mL。

Three polysaccharides （CAP-H,CAP-M and CAP-U） were extracted from Camptotheca acuminate fruit by hot water extraction,microwave-assisted extraction and ultrasonic-assisted extraction methods.Their physiochemical properties were analyzed by Fourier transform infrared spectroscopy （FTIR） analyses and differential scanning colorimeter （DSC）.In additon,their antioxidant activities were evaluated by scavenging capability of DPPH free radical,hydroxyl free radical,total reducing power test and iron ion chelating ability in vitro.The results showed that the polysaccharide yield of microwave-assisted extraction was significantly higher than the other two methods.But there was no significant difference of physiochemical properties between the three polysaccharides.The hydroxyl free radicals and DPPH radical scavenging abilities of CAP-H were higher than CAP-M and CAP-U,and the IC50 value were 0.775 mg/mL and 0.648 mg/mL,respectively.And CAP-H also showed significantly higher reducing power than CAP-M and CAP-U.But CAP-M showed the best iron ion chelating ability with IC50value 1.745 mg/mL.