知母中牡荆素的分离及盐炙前后含量比较

Separation and Content Comparison of Vitexin from Anemarrhenae Rhizoma Before and After Salt Processing

目的：对知母化学成分进行研究,建立测定知母中牡荆素含量的方法,比较盐炙前后牡荆素含量差异。方法采用硅胶柱色谱等技术对知母70%乙醇提取物进行分离、纯化,通过理化性质和波谱数据鉴定化合物结构。采用高效液相色谱法测定,Ecosil 色谱柱（4.6 mm±150 mm,5μm）,乙腈-0.2%冰醋酸溶液（14.5∶85.5）为流动相,流速1.0 mL/min,检测波长340 nm。结果该化合物为牡荆素,在0.0398～1.99μg范围内线性关系良好,r＝0.9998,平均回收率为98.02%,RSD＝0.21%。生知母中牡荆素含量为0.0085%,盐知母含量为0.0081%。结论从知母中首次分离得到牡荆素,所建立的方法准确、专属性强、灵敏度高,知母盐炙后牡荆素含量略降低。

Objective To study the chemical components of Anemarrhenae Rhizoma;To establish a method to determine the content of vitexin;To compare the content difference of vitexin from Anemarrhenae Rhizoma before and after salt processing. Methods 70% ethanol extract of Anemarrhenae Rhizoma was separated and purified by silica gel column chromatography technique, and compound was identified by physicochemical properties and spectral data. HPLC was used with Ecosil column （4.6 mm＆#215;150 mm, 5μm）, mobile phase of acetonitrile-0.2%acetic acid solution （14.5∶85.5）, velocity of 1.0 mL/min, and determine wavelength of 340 nm. Results The compound was vitexin, a good linearity （r=0.999 8） in the range of 0.039 8-1.99μg. The average recovery rate was 98.02%, RSD=0.21%. Vitexin content was 0.008 5% in crude Anemarrhenae Rhizoma, 0.008 1% in processed products. Conclusion This is the first time separation of vitexin from Anemarrhenae Rhizoma. The method for content determination of vitexin is accurate, specific, and highly sensitive in the present experiment. Content of vitexin decreases slightly in processed products of Anemarrhenae Rhizoma compared with crude Anemarrhenae Rhizoma.