ObjectiveThe alkaloids in Berberis poiretii were studied in this paper, and the aim is to provided references for the effective utilization of B. poiretii.

MethodUsing the extraction yield of total alkaloids and the diameter of bacteriostatic circle as indicators of investigation, total alkaloids were extracted from Berberis poiretii with 10%-70% ethanol. The results showed that the optimal yield of total alkaloids was with 27% ethanol. Three single factor experiments were designed for ratio of liquid to solid, extraction temperature and extraction time. Based on the single factor experiment analysis, the mathematical model was established by Plackett-Burman design, steepest ascent test and response surface design of central composite test.

ResultThe results showed that the optimum extracting conditions were: 27%(V/V)ethanol concentration, 52℃, solvent-to-solid ratio of 32mL/g, ultrasonic power 800W; the extraction time was 50min when the pH value of the extract was 2.2; the extraction time was 25min when the pH value of the extract was 7.6; the extraction time was 25min when the pH value of the extract was 8.5. Under the above conditions, the extraction amount of total alkaloids in Berberis poiretii was 16.24±0.54mg/g, which was increased by 1.31 times compared with the single ultrasonic assisted method, and the diameter of its bacteriostatic circle was 91.21±0.37mm.

ConclusionIt is concluded that the semi-bionic method assisted by ultrasonic is better than the single ultrasonic method in the extraction of total alkaloids from Berberis poiretii. The extraction amount was increased by 1.31 times and the bacteriostatic effect was increased by 1.07 times. The extraction amount of berberine under the above conditions is closed to the average extraction amount 16.6±0.6mg/g and the antibacterial effect is improved evidently.