蒙古黄芪中芒柄花素含量的测定及黄酮类成分提取工艺的优化

Determination of formononetin and optimization of the extraction conditions for flavonoid constituents of astragalus membranaceus var.mongholicus

目的建立芒柄花素的含量测定方法,优选黄芪中黄酮类成分的提取工艺。方法采用高效液相色谱-紫外检测法,建立芒柄花素的含量测定方法,以芒柄花素含量为指标,用正交设计法对影响超声提取的因素如乙醇浓度、乙醇用量、提取次数和超声时间进行考察,优化提取工艺。结果芒柄花素在1～40μg/ml范围内线性关系良好,以峰面积(A)对浓度(C)进行线性回归,方程为A=212096C+3958.7,r2=0.9999。日内、日间相对标准差(RSD)均<5%;平均回收率均在98.0%～102.0%;优化提取条件为加15倍量75%乙醇,连续提取3次,每次20min。结论所建立的含量测定方法可用于蒙古黄芪中芒柄花素的含量测定,优化的提取工艺具有效率高和操作简便等优点。

Objective To establish the determination method of formononetin by high performance liquid cbromatography and ultraviolet （HPLC-UV） detection, and to optimize the extraction conditions for flavonoids of Astragalus membranaceus var.mongholicus. Methods Formononetin in Astragalus membranaceus var.mongholicu was determined by HPLC-UV detection. Factors associated with ultrasonic extraction of flavonoids, including concentration and amount of ethanol used, times of extraction and ultrasonic duration, were investigated using orthogonal design table with for- mononetin as a target index. The optimized extraction method was determined based on the experiment results. Results Formononetin concentration showed good linearity within a range of 1-40 μg/ml. A linear regression equation was formulated as A=212096C＋3958.7 （r^2=0.9999）, where A denotes the peak area and C the concentration. The intra- and inter-day RSDs of precision were less than 5%. The mean recovery was 98.0%-102.0%. Optimized extraction conditions were found to be adding 15 parts of 75% ethanol to 1 part of material for three consecutive extractions, 20 minutes each time. Conclusion The HPLC method established in the present study can be used to determine the contents of formononetin in Astragalus membranaceus var.mongholicus. The optimized extraction method showed promise with higher extraction efficiency and simple processing.