黄芩茎叶总黄酮制备工艺优化研究

Preparation of Total Flavonoids from Stem and Leave of Scutellaria Baicalensis<\i>

  • 摘要: 目的 优选黄芩茎叶总黄酮制备工艺,为黄芩茎叶资源的合理利用开发提供依据。方法 以黄芩茎叶中8个黄酮类化合物的转移率为指标,采用单因素考察结合正交试验优选黄芩茎叶黄酮的提取工艺;比较酸沉法和大孔树脂法纯化茎叶总黄酮的转移率,并对大孔树脂纯化工艺进行优选。结果 以12倍量40%乙醇热回流提取3次,每次1 h,为最佳提取工艺。提取物的纯化结果显示,大孔树脂法中黄芩茎叶黄酮的总体转移率(92.53%)显著高于酸沉法(76.69%)。在pH为1.01时,酸沉法虽然可以使野黄芩苷等化合物转移率达90%以上,但含量丰富的二氢黄酮类化合物异红花素-7-O-β-D-葡萄糖醛酸苷、红花素-7-O-β-D-葡萄糖醛酸苷的转移率仅为64.76%、68.57%,而使用大孔树脂法纯化,其转移率均可达90%以上,可以实现各目标成分的高效转移。经优选,0.26 g/mL药液上样,上样量为每10 g HP-20型干树脂上样2.08 g干燥提取物,树脂柱径高比为1∶3,4 BV纯水除杂后,以30%乙醇洗脱4 BV,为最佳纯化工艺,所得总黄酮质量分数可达66.03%。结论 建立了稳定且环境友好型黄芩茎叶总黄酮制备工艺,可为黄芩茎叶的进一步开发利用提供参考。

     

    Abstract: OBJECTIVE To optimize the technology of preparing total flavonoids from the stem-leave of Scutellaria Baicalensis and provide basis for the rational utilization and development of stem-leave resources of Scutellaria Baicalensis. METHODS The transfer rates of 8 flavonoids compounds in the stem-leave of Scutellaria Baicalensis and the single factor combined with orthogonal design were applied to optimize the extraction process. In addition, the transfer rates of acid deposition and macroporous resin method to purify total flavonoids in the stem-leave were compared, and the purification technique of macroporous resin method was optimized. RESULTS The best extraction technology was to use 12 times amount of 40% ethanol with heat reflux, one time an hour. According to the result of purification of extraction, the transfer rate of total flavonoids in the stem-leave of Scutellaria Baicalensis with macroporous resin method was 92.53%, higher than that with acid deposition, 76.69%. When pH value was 1.01, with acid deposition, the transfer rate of compounds such as scutellarin was over 90%, while the transfer rate of enriched dihydroflavanone was quite low, for instance, 64.76% for isocyanin-7-O-β-D- glucuronide and 68.75% for safflower-7-O-β-D-glucuronide. However, as for macroporous resin method, the transfer rate could come up to over 90%, which promoted the efficient transfer of each target component. On the basis of optimum, the resource volume was 2.08 g dry extract per 10 g HP-20 type dry resin with 0.26 g/mL liquor. The ratio of resin column diameter to height was 1∶3. The perfect purification technology was to wash the sample with 4 BV of distilled water and eluted with 4 BV of 30% ethanol, which could obtain 66.03% mass fraction of total flavonoids. CONCLUSION This study establishes a firm and environmental-friendly method of preparing total flavonoids from the stem-leave of Scutellaria Baicalensis and provides some reference for the further development and utilization of the stem-leave of Scutellaria Baicalensis.