天麻HPLC指纹图谱建立及判别分析

天麻为常用名贵中药,使用量大、价格高,常有性状相似的伪品出现;并且冬天麻(栽培天麻)与春天麻(多为野生天麻)的价格差异较大,真伪优劣难以鉴别。为此,广泛收集了48份冬天麻、春天麻、天麻饮片、天麻粉等不同性状的天麻样品和9种10份天麻伪品,应用HPLC-DAD-MS技术,通过优化供试液的制备方法、色谱条件和质谱条件,测定、比较这些样品的HPLC图,并进行相似度及Fisher判别分析。结果表明,这48份天麻样品的HPLC图相似,其相似度大于0.848(n=48);以其平均图谱作为指纹图谱。有11个分离良好的共有峰,选择6个主要色谱峰作为特征峰,经与对照品比较,UV和MS数据分析,分别鉴定为天麻素、对羟基苯甲醇、巴利森苷A、巴利森苷B、巴利森苷C、巴利森苷E,均为天麻的药效成分。10份天麻伪品与天麻HPLC指纹图谱明显不同,相似度低于0.042,并且未发现天麻HPLC指纹图谱的特征峰。说明根据指纹图谱的相似度或者特征峰均可鉴别天麻的真伪。对15份冬天麻和11份春天麻的HPLC图分析结果表明,两者的HPLC图相似(平均相似度为0.908);但特征峰的强度不同,冬天麻中天麻素、巴利森苷A和C的强度低于春天麻;以天麻HPLC图中11个共有峰的面积为变量建立的Fisher非标准化判别函数和线性判别函数均能100%判别冬天麻和春天麻,予以准确鉴别。

Development of Tianma HPLC fingerprint and discriminant analysis

Tianma(the tuber of Gastrodia eleta) is a widely used and pricy Chinese herb. Its counterfeits are often found in herbal markets, which are the plant materials with similar macroscopic characteristics of Tianma. Moreover, the prices of Winter Tianma(cultivated Tianma) and Spring Tianma(mostly wild Tianma) have significant difference. However, it is difficult to identify the true or false, good or bad quality of Tianma samples. Thus, a total of 48 Tianma samples with different characteristics(including Winter Tianma, Spring Tianma, slice, powder, etc.) and 9 plant species 10 samples of Tianma counterfeits were collected and analyzed by HPLC-DAD-MS techniques. After optimizing the procedure of sample preparation, chromatographic and mass-spectral conditions, the HPLC chromatograms of all those samples were collected and compared. The similarities and Fisher discriminant analysis were further conducted between the HPLC chromatograms of Tianma and counterfeit, Winter Tianma and Spring Tianma. The results showed the HPLC chromatograms of 48 Tianma samples were similar at the correlation coefficient more than 0.848(n=48). Their mean chromatogram was simulated and used as Tianma HPLC fingerprint. There were 11 common peaks on the HPLC chromatograms of Tianma, in which 6 main peaks were chosen as characteristic peaks and identified as gastrodin, p-hydroxybenzyl alcohol, parishin A, parishin B, parishin C, parishin E, respectively by comparison of the retention time, UV and MS data with those of standard chemical compounds. All the six chemical compounds are bioactive in Tianma. However, the HPLC chromatograms of the 10 counterfeit samples were significantly different from Tianma fingerprint. The correlation coefficients between HPLC fingerprints of Tianma with the HPLC chromatograms of counterfeits were less than 0.042 and the characteristic peaks were not observed on the HPLC chromatograms of these counterfeit samples. It indicated the true or false Tianma can be identified by either the similarity or characteristic peaks on HPLC fingerprint. Comparing the Winter Tianma with Spring Tianma showed that the HPLC chromatograms of 15 winter Tianma samples and 11 spring Tianma samples were similar at the mean correlation coefficient of 0.908. But the intensity of the characteristic peaks were different between the two groups of Tianma samples, i.e. the intensity of gastrodin, paishin A and C in winter Tianma was lower than those in spring Tianma. The Winter Tianma and Spring Tianma could be discriminated by either the Fisher unstandardized discrimination function or Linear discriminant function, based on the peak areas of 11 common peaks on HPLC chromatograms as variate.