HPLC法测定草乌叶中2个阿朴啡生物碱含量

目的：建立测定草乌叶中2个阿朴啡生物碱（N-醛基去甲海罂粟碱和去甲海罂粟碱）含量的色谱方法，用于指导草乌叶的质量控制。方法：以N-醛基去甲海罂粟碱和去甲海罂粟碱为指标，采用XBridge C₁₈色谱柱（4.6 mm×250 mm，5 μm），乙腈（A）-40 mmol·L^-1醋酸铵水溶液（氨水调pH至10.5）（B）（33：67）为流动相，流速1.0 mL·min^-1，检测波长为302 nm，柱温30℃，进样量10 μL。结果：N-醛基去甲海罂粟碱和去甲海罂粟碱质量浓度分别在9.25~370.0 μg·mL^-1（r=0.999 9，n=6）、9.83~393.3 μg·mL^-1（r=0.999 9，n=6）范围内线性关系良好，方法的平均回收率（n=6）分别为97.8%（RSD=2.2%）、98.9%（RSD=1.6%）；12批草乌叶中N-醛基去甲海罂粟碱和去甲海罂粟碱含量分别为0.071~0.388 mg·g^-1和0.320~2.49 mg·g^-1。同时考察了不同采收期草乌叶药材中这2种成分含量的影响，随着采收期的推迟，含量先增后减。结论：本试验建立的方法可用于草乌叶药材中生物碱的含量测定，为该药材质量标准的完善提供参考，并阐明了草乌叶采收期的科学内涵。

Objective:To establish a method for the determination of two aporphine alkaloids N-formylnorglaucine and norglaucine in the leaf of Aconitum kusnezoffii Reichb.by HPLC,so as to instruct the quality control of the herb.Methods:N-formylnorglaucine and norglaucine were index components.HPLC analysis was carried out using an XBridge C₁₈ column (4.6 mm×250 mm,5 μm).The mobile phase was acetonitrile-40 mmol·L^-1 ammonium acetate solution (adjusted pH to 10.5 with ammonia solution) (33:67) with isocratic elution at the flow rate of 1.0 mL·min^-1,the detection wavelength was 302 nm,the column temperature was 30,and the injection volume was 10 μL.Results:The linear ranges of N-formylnorglaucine and norglaucine were 9.25-370.0 μg·mL^-1 (r=0.999 9,n=6),9.83-393.3 μg·mL^-1 (r=0.999 9,n=6),respectively.The average recoveries (n=6) of the two alkaloids were 97.8%(RSD=2.2%) and 98.9% (RSD=1.6%),respectively.The contents of the two alkaloids in 12 samples were 0.071-0.388 mg·g^-1,and 0.320-2.49 mg·g^-1,respectively.The method has been successfully applied to the analysis of Aconiti kusnezoffii Folium in different harvest times.The contents of the two alkaloids increased primarily,and then decreased with the postponing of harvest.Conclusion:The established method is proved to be accurate and sensitive for the determination of alkaloids in Aconiti Kusnezoffii Folium,and may be useful for the quality improvement of this herbal medicine.Moreover,these results elucidate the scientific significance for the suitable harvest time of this herb.