葛花中异黄酮含量及其酸水解转化率的检测

Decoction of Isoflavone Content and Its Acid Hydrolysis Conversion Rate in the Flower of Pueraria lobata

目的:建立检测葛花中异黄酮含量及其酸水解转化率的方法。方法:以葛花为原料,采用乙醇提取、乙酸乙酯萃取、乙醇重结晶纯化制备以鸢尾苷为主要成分的葛花异黄酮,经盐酸水解转化为鸢尾苷元。通过筛选溶剂和波长建立测定鸢尾苷与苷元的紫外分光光度(UV)法,计算葛花异黄酮含量及鸢尾苷酸水解转化率(以鸢尾苷元的相对百分含量表示),并与高效液相色谱法(HPLC)检测结果进行比较,评价UV法的准确性。结果:UV法溶剂选择含有1%三乙胺的70%乙醇溶液,波长选择339、274 nm,鸢尾苷元在8.80~29.33 nmol/m L浓度范围内线性关系良好(r=0.999 9);精密度(n=6)、稳定性(n=5)、重复性(n=6)试验的RSD均小于1.94%,平均加样回收率为99.7%(RSD=1.77%,n=9)。UV法与HPLC法比较,总黄酮含量(17.64~25.55 nmol/m L vs.17.39~24.40 nmol/m L)、鸢尾苷元的相对百分含量(57.65%~87.59%vs.55.62%~91.14%)比较,差异无统计学意义(P>0.05)。结论:本研究建立的方法准确、可靠,可用于鸢尾苷酸水解转化率的快速检测。

OBJECTIVE： To establish a method for the decoction of isoflavone content and its acid hydrolysis conversion rate in the flower of Pueraria lobata. METHODS： Using the flowers of Pueraria lobata as raw material, the isoflavone with main com- ponent of tectoridin in the flower of P. lobata was prepared with ethanol, ethyl acetate extracted, ethanol recrystallized and puri- fied, and it was converted to tectorigenin with hydrolysis in hydrochloric acid. By screening the solvent and wavelength, UV spec- trophotometry was established to determine tectovidin and tectorigenin, and calculate the isoflavone content and acid hydrolysis con version rate of tectoridin （expressed by the relative percentage of tectorigenin）. It was compared with HPLC detection results, the accuracy of UV method was evaluated. RESULTS： The solvent was 70% ethanol solution containing 1% triethylamine, and the iso- flavone content was detected at wavelength of 339, 274 nm. The linear range of tectoridin was 8.80-29.33 nmol/mL （r=0.999 9）. RSDs of precision （n=6）, stability （n=5） and reproducibility （n=6） tests were lower than 1.94% ; average recovery was 99.7% （RSD=1.77%, n=9）. There were no statistical significances in the contents of total flavonoids （UV： 17.64-25.55 nmol/mL vs. HPLC： 17.39-24.40 nmol/mL） and the relative percentage of tectorigenin （UV： 57.65%-87.59% vs. HPLC： 55.62%-91.14%）. CONCLUSIONS ： The established method is accurate, reliable, and can be used for the rapid determination of acid hydrolysis con- version rate of tectoridin.