Study on the Optimization of Ethanol Extraction Techniques for Radix astragali

[Objective] The aim was to optimize the extraction techniques for Radix astragali.[Method] With extract yield,astragaloside content and total flavone content as indices,the influencing factors on the extraction of active components from R.astragali were investigated.[Result] The best technological conditions for the extraction of active components from R.astragali were as follows: 70% ethanol,extraction temperature of 70 ℃,solid-liquid ratio of 1∶12 and extraction time of 3 h.Under these technology conditions,the extract yield was about 25%,the astragaloside content was more than 3% and total flavone content was about 0.8%.[Conclusion] The optimal technology for the ethanol extraction of R.astragali was scientific and economical.And can save resources and instruct the industrial practice effectively.