葛根黄酮的提取工艺及三波长—分光光度法测定其含量

Study on extracting technology of flavonoids from Pueraria Lobata Ohwi and determination of flavonoids by three-wavelength spectrophotometry

采用乙醇回流提取法,考察乙醇浓度、提取时间、料液比、提取次数4个单因素对葛根黄酮提取率的影响,并采用L9(34)正交试验确定葛根黄酮的最佳提取工艺条件。文章以芦丁为标准品,采用三波长—分光光度法测定葛根黄酮的含量可以消除吸收峰不对称等影响。实验结果:回归方程为ΔA=0.011 7+0.012 6c,相关系数r=0.999 6,芦丁的浓度在0—30μg.mL-1范围内,分别在波长λ1=495 nm,λ2=412 nm,λ3=368 nm处测吸光度时,ΔA与浓度c之间呈良好的线性关系。影响葛根黄酮提取率的各因素主次顺序为:乙醇浓度>提取时间>料液比>提取次数。最佳提取工艺参数为:葛根原料过80目药典筛、提取温度70℃为前提条件,乙醇浓度为70%,料液比为1∶20,提取2次,每次2.5 h,在此条件下葛根黄酮提取率为0.145 2 mg/g。

To optimize the ethanol reflux extraction of flavonoids from Pueraria lobata Ohwi,ethanol concentration,extraction time,material-solvent ratio and extraction times were used as the criteria in the progressive single factor experiment,and an orthogonal test of L9（34） was designed.Taking rutin as the standard,determination of Pueraria lobata Ohwi flavonoids measured by adopting three-wavelength spectrophotometry can eliminate the absorbance error.The regression equation of concentration ΔA was obtained and listed as follows： ΔA=0.011 7＋0.012 6c with a relation coefficient r=0.999 6.The experimental results demonstrating the rutin concentrations in 0-30 μg·mL-1 was measured at wavelength λ1=495 nm,λ2=412 nm,λ3=368 nm.The influence factors＇ priority was： the ethanol concentrationextraction timematerial-solvent ratioextraction times.For the primise condition of puerarin material for a 80 mesh pharmacopoeia sieve and temperature of 70 ℃,the optimum ethanol extraction process was as follows： ethanol concentration of 70%,material-solvent ratio of 1∶ 20,extraction times of 2 and each time of 2.5 hours.In this condition,the Pueraria lobata Ohwi flavonoids extraction rate was 0.145 2 mg/g.