分光光度法检测昆仑雪菊总黄酮络合显色体系适应性研究

Adaptability Study of the Complexation and Color Rendering Systems on Determination of Total Flavonoids in Kunlun Coreopsis tinctoria by Spectrophotometry

本研究以选择最适合的分光光度络合显色体系检测昆仑雪菊总黄酮(Coreopsis tinctoria flavonoids,CTFs)含量为目标,采用60%乙醇(v/v)回流对雪菊总黄酮进行提取,依次采用石油醚、乙酸乙酯、正丁醇对雪菊总黄酮提取物进行萃取,得石油醚、乙酸乙酯(EAE)、正丁醇(n-BuOH-E)萃取物。分别以芦丁、槲皮素、表儿茶素(EC)为对照品,采用经典络合显色体系包括NaNO2-Al(NO3)3/AlCl3-NaOH和KAc-Al(NO3)3/AlCl3对EAE、n-BuOH-E中黄酮含量进行检测。为确定最佳对照品种类及络合显色体系,实验同时采用高效液相色谱(HPLC)对EAE、n-BuOH-E中黄酮含量进行测定。HPLC法结果表明EAE和n-BuOH-E中黄酮含量分别为48.43%和43.19%,经筛选,分光光度法中采用芦丁KAc-AlCl3体系测得EAE和n-BuOH-E黄酮含量与HPLC法最为接近。因此,确定该方法为测雪菊乙酸乙酯、正丁醇萃取物及雪菊总黄酮提取液黄酮含量的最佳方法,采用该方法对雪菊总黄酮提取液中黄酮含量进行检测,结果为10.65%。

This work aimed at choosing of a suitable spectrophotometric method for the analysis of Coreopsis tinctoria flavonoids(CTFs).Firstly,the total flavonoids in Coreopsis tinctoria were extracted with 60% ethanol(v/v).Then petroleum ether,ethyl acetate and n-butanol were used successively to soke the total flavonoids and the petroleum ether extract,ethyl acetate extract(EAE)and n-BuOH-E extract(n-BuOH-E)were obtained separately.The content of flavonoids in EAE and n-BuOH-E were detected by classical complexation and color rendering systems including NaNO2-Al(NO3)3/AlCl3-NaOH and KAc-Al(NO3)3/AlCl3,and rutin,quercetin and epicatechin(EC)were used as reference substances,respectively.The content of flavonoids in EAE and n-BuOH-E were also determined simultaneously by high performance liquid chromatography(HPLC)to verify the adaptability of the different complexation method.HPLC results showed that the content of flavonoid in EAE and n-BuOH-E was 48.43% and 43.19% respectively.By comparison,the content of flavonoids in EAE and n-BuOH-E measured with rutin KAc-AlCl3 system was closest to that determined by HPLC.Therefore,rutin KAc-AlCl3 was considered to be the optimal method for the determination of CTFs.Then rutin KAc-AlCl3 method was used to the detection of total flavonoids in Coreopsis tinctoria and the result was 10.65%.