尖叶四照花叶片多糖含量测定及抗氧化活性分析

Spectrometric Determination and Antioxidant Activity Analysis of Polysaccharides in the Leaves of Cornus elliptica

为快捷、高效地测定尖叶四照花叶片多糖含量,同时评价其抗氧化活性,采用荧光光谱法测定多糖含量,通过单因素及正交实验确立最佳测定条件;在此基础上,测定该多糖对DPPH自由基和O_(2)^(-)自由基的清除能力.结果显示,采用荧光光谱法测定尖叶四照花叶片多糖含量的最佳条件为:0.5 mL 0.9 mol/L NaOH溶液,1 mL 3.0 mmol/L CTAB溶液,反应时间为30 min,测定散射波长为370 nm,在3~18μg/mL的范围内,多糖含量与荧光吸收值呈线性关系.荧光光谱法与苯酚-浓硫酸法测定同一多糖样品,平均含量分别为28.13±0.15、31.27±0.46 mg/g,结果较为相近;表明荧光光谱法测定尖叶四照花叶片多糖含量具有可行性.抗氧化活性分析表明,该多糖对DPPH自由基和O_(2)^(-)自由基清除能力均与多糖含量呈正相关,并显示较强的抗氧化活性.

In order to rapidly and efficiently determine the content of polysaccharide in the leaves of Cornus elliptica and evaluate its antioxidant activity,we determined,the content of polysaccharide by fluorescence spectrometry and established the optimal determination conditions by univariate and orthogonal experiments.On this basis,the scavenging ability of the polysaccharides on DPPH radicals and O_(2)^(-) free radicals was determined.The results showed that the optimal conditions for the determination of polysaccharide content in the leaves by fluorescence spectroscopy were:0.5 mL 0.9 mol/L NaOH solution,1 mL 3.0 mmol/L CTAB solution,the reaction time was 30 min,and the scattering wavelength was 370 nm,and the polysaccharide content of Cornus elliptica was linearly related to the fluorescence absorption value in the range of 3~18μg/mL.The average contents of the same polysaccharide samples were 28.13±0.15,31.27±0.46 mg/g by fluorescence spectrometry and phenol sulfuric acid method respectively.The results showed that the fluorescence spectrometry was feasible for determining the content of polysaccharide in the leaves of the Cornus elliptica.Antioxidant activity tests showed that the scavenging ability of polysaccharides in the leaves of Cornus elliptica on DPPH radicals and O_(2)^(-) free radicals was positively correlated with the content of polysaccharide,and showed strong antioxidant activity.