目的 优选黄芩提取物精制工艺。方法 采用抑菌率法测定黄芩提取物抑菌药效，HPLC法测定其有效成分的量，并采用正交试验设计，以抑菌率及有效成分提取量为指标，归一值法综合评分，考察酸沉时药液浓度和pH值、2次保温温度、保温时间和静置时间的影响。并比较精制前后的提取物的抑菌药效，优选其制备工艺。结果 确定最佳精制工艺为药液浓缩到含生药0.5 g/mL，用2 mol/L盐酸调节pH值至2～2.5，80 ℃保温1 h，静置24 h，减压滤过，沉淀物加1倍量的水混悬，用40%氢氧化钠溶液调节pH值至7.0，加等量95%乙醇，搅拌使溶解，滤过，滤液再次如上法酸沉，减压滤过，沉淀水洗至pH值5.0，95%乙醇洗涤，挥尽乙醇，减压干燥，即得。结论 该优选工艺所得提取物有较高的抑菌药效，工艺稳定、可行。

Objective To optimize the purification technology for the extract from Scutellaria baicalensis. Methods The antimicrobial efficacy of S. baicalensis extract in vitro was evaluated with bacteriostatic rate test. And the contents of the active components in S. baicalensis extract were determined using HPLC method. Taking the bacteriostasis rate and the extraction weight of the active components as indexes, using the overall normalizing method for grading comprehensively, orthogonal test was employed to optimize the purification conditions of S. baicalensis extract, such as the concentration degree and pH value of the extract before acid precipitation, the holding temperature and time, and the standing time. The antimicrobial effects of S. baicalensis extract before and after purification were compared to determine the optimal process. Results The optimal purification process was as follows: concentrating the water extract to the degree of 1∶2, regulating the pH value to 2－2.5 with 2 mol/L HCl solution, holding the temperature of 80 ℃ for 1 h, and standing for 24 h, then filtering under decompression, resuspending the precipitate with equivalence water, regulating the pH value to 7.0 with 40% NaOH solution, adding equivalence 95% alcohol, agitating to dissolve and filter, then adding HCl solution to precipitate and filter as before, washing the precipitate with water to regulate the pH value to 5.0, and at last washing the precipitate with 95% alcohol, drying under reduced pressure to obtain the product. Conclusion The product of this process has high antimicrobial efficacy and retention rate of active components, which proves that the preparation process is feasible, stable, and reasonable.

基金项目：山东省中医药科技发展计划重点项目（2011Z-003-1）