淡竹叶多酚的提取纯化工艺优化、组分分析及体外抗氧化活性研究

Optimization of extraction and purification process,component analysis and antioxidant activity in vitro of polyphenols from Lophatherum gracile Brongn

目的确定淡竹叶多酚提取纯化工艺,分析主要成分及体外抗氧化活性。方法采用超声辅助提取淡竹叶多酚,通过响应面实验确定最佳提取条件。选取适合淡竹叶多酚纯化的大孔树脂,对纯化工艺参数进行优化。通过高效液相色谱-质谱法(high performance liquid chromatography-mass spectrometry,HPLC-MS)鉴定淡竹叶多酚的主要成分,并评价其体外抗氧化活性。结果淡竹叶多酚的最佳提取工艺参数为:乙醇体积分数60%、超声功率500 W、料液比1:25(g/mL)、超声时间24 min及超声温度59℃,该条件下淡竹叶多酚提取量为8.01 mg/g。淡竹叶多酚纯化工艺参数为:上样质量浓度6 mg/mL、pH 4、流速2 mL/min、解吸液为70%乙醇、解吸体积90 mL,纯化后的淡竹叶多酚纯度由12.86%提高到76.18%。通过HPLC-MS鉴定出16种酚类成分,且纯化后多酚有较高的抗氧化活性。结论本研究得到了淡竹叶多酚提取纯化工艺,得到的多酚纯化物有明显的抗氧化活性。

Objective To determine the extraction and purification process of polyphenols from Lophatherum gracile Brongn.,and study the main components and antioxidant activity in vitro.Methods Ultrasonic-assisted extraction of polyphenols from Lophatherum gracile Brongn.was used,and the optimal extraction conditions were determined by response surface test.The macroporous resin suitable for the purification of polyphenols from Lophatherum gracile Brongn.was selected,and the purification process parameters were optimized.The main components of polyphenols from Lophatherum gracile Brongn.were identified by high performance liquid chromatography-mass spectrometry(HPLC-MS),and the antioxidant activity in vitro was subsequently evaluated.Results The extraction process parameters of polyphenols from Lophatherum gracile Brongn.were as follows:Ethanol volume fraction 60%,ultrasonic power 500 W,material-liquid ratio 1:25(g/mL),ultrasound time 24 min,ultrasound temperature 59℃,the maximum content of polyphenols from Lophatherum gracile Brongn.was 8.01 mg/g under these conditions.The purification process parameters of polyphenols from Lophatherum gracile Brongn.were as follows:Mass concentration of 6 mg/mL,pH 4,loading flow rate of 2 mL/min,elution concentration of 70%ethanol,elution volume of 90 mL,and the purity of purified polyphenols from Lophatherum gracile Brongn.increased from 12.86%to 76.18%.Sixteen kinds of phenolic components were identified by HPLC-MS,and the purified polyphenols had high antioxidant activity.Conclusion In this study,the extraction and purification process of polyphenols from Lophatherum gracile Brongn.is obtained,and the purified polyphenols shows significant antioxidant activity.