以提取温度、液料比、浸泡时间和提取时间为影响因素,以多糖提取率为考察指标,在单因素试验基础上,采用均匀设计法优选油樟叶多糖的提取工艺.结果表明:由二次回归模型得到优选工艺条件为,提取温度100℃,液料比16∶ 1(mL∶g),浸泡时间0 min,提取时间215 min,在此条件下,油樟叶多糖提取率为14.36％.以抗坏血酸为阳性对照,采用化学比色法测定油樟叶多糖的体外抗自由基活性.结果表明:油樟叶多糖对DPPH、超氧阴离子和羟自由基均有一定清除能力,其半数清除浓度(EC50)分别为0.086、1.075和0.905 mg/mL,其抗自由基活性弱于抗坏血酸.

On the basis of single factor tests,the four influential factors including temperature,liquid solid ratio,soaking time and extraction time were investigated on the extraction rate of the polysaccharides from Cinnamomum longepaniculatum leaves.The optimum extraction technology was acquired by uniform design test.The optimum extraction conditions by quadratic regression model were as follows:extraction temperature 100 ℃,ratio of liquid-solid 16 (mL/g),soaking time 0 min,extraction time 215 min.Under these conditions,the extraction rate of polysaccharides was 14.36％.The anti-free radical activity of polysaccharides was determined by chemical colorimetric method in vitro,and ascorbic acid was used as positive control.Results showed that the polysaccharides from C.longepaniculatum leaves showed certain scavenging activity on DPPH,super oxygen-anion and hydroxyl free radical with the median effective concentration (EC50) values of 0.086,1.075 and 0.905 mg/mL,respectively.The anti-free radical activity of the polysaccharides from Cinnamomum longepaniculatum leaves was weaker than that of ascorbic acid.