Folin-Ciocalteu法测定鱼腥草多酚的含量

Determination of Polyphenol Content in Houttuynia cordata Thunb. by Folin-Ciocalteu Colorimetric Method

目的:探索优化Folin-Ciocalteu法测定鱼腥草中多酚含量。方法:运用不同的溶剂超声提取鱼腥草叶片,比较不同时间提取物用Folin-Ciocalteu法测得的吸光度。并以乙醇2h提取液为对象研究不同的碳酸钠溶液、Folin-Ciocalteu显色剂加入量、反应温度及时间对吸光度大小及稳定性的影响。结果:甲醇提取效率最高,其次为乙醇、丙酮和水;提取时间2h;较适宜测定方法为采用0.5mL提取液,加入2.0mL20%的碳酸钠缓冲液、1.5mLFolin-Ciocalteu显色剂,蒸馏水定容至50.0mL,55℃保温1.5h,测定波长为760nm。结论:该方法比较快速、准确和稳定,适合推广。

Objective： To establish a quantitative method to assay total polyphenols in Houttuynia cordata Thunb..Method： Four solvents （methanol,ethanol,acetone and water） were used to extract Houttuynia cordata Thunb.with the assistance of ultrasonic in order to explore the effects of extraction solvent type and length of extraction on the extraction of total polyphenols.Subsequently,the 2 h ethanol extract was used to optimize 20% sodium carbonate amount,Folin-Ciocalteu regent amount,reaction temperature and length of reaction.Results： Methanol was the best extraction solvent,followed by ethanol,acetone and water.The optimum conditions for determining total polyphenols in Houttuynia cordata Thunb.were as follows： a mixture of 0.5 mL of methanol extract,2.0 mL of 20% sodium carbonate and 1.5 mL of Folin-Ciocalteu reagent diluted with distilled water to 50.0 mL for incubation at 55 ℃ for 1.5 h,followed by detection at 760 nm.Conclusion： The method is simple,accurate and provides an appropriate method for measuring total polyphenols in Houttuynia cordata Thunb.