Extracting techniques for optimizing astragaloside IV by orthogonal test

To optimize the extracting techniques for astragaloside IV from astragalus by comparing the alcohol-extraction with the water-extraction,with the extraction rate of astragaloside IV as criteria,the influencing factors on both methods of water-extraction and alcohol-extraction were studied by orthogonal test.Result: under 8 hours of soak period and grinding for astragalus,the alcohol concentration and pH shows significant influence on alcohol-extraction while only the pH shows strong influence on water-extraction.So the best process conditions for water-extraction are at 1-hour boiling time,pH 12 and 60 ℃ of extraction temperature,while for alcohol-extraction are at 60% alcohol concentration,pH 12 and 6 times amount of alcohol.It can be concluded that the extraction rate of astragaloside IV by alcohol-extraction is higher than by water-extraction.