HPLC特征指纹图谱结合化学计量学比较川牛膝及其混淆品、掺混品化学成分差异

Comparison of chemical constituents between Cyathula offinalis and adulterant and their admixture by HPLC characteristic chromatogram fingerprint combined with chemometrics

川牛膝的主要混淆品为同属植物头花杯苋的根,研究报道其在性味和药理活性上存有明显差异,仅可作为地方习惯用药,不得代替川牛膝入药。但因头花杯苋外观形态上与川牛膝十分相似,且杯苋甾酮含量也能达到现行药典限量,导致市场上多以冒充或掺混形式出售,这严重地影响了川牛膝的临床用药安全和道地药材开发。鉴于此,该文采用HPLC特征指纹图谱技术试图揭示川牛膝、混淆品头花杯苋、掺混川牛膝在多组分下的化学特征成分差异,以期为川牛膝区别用药和真伪鉴别提供有力支撑。通过测得川牛膝及其混淆品、掺混品色谱图,得出65个不同组分,以建立26×65的峰面积数据矩阵,并进行特征峰差异分析、相似度分析、聚类分析和主成分分析。特征峰差异分析得出头花杯苋及其掺混品特征峰较川牛膝多且响应值高,筛选出的9个特征峰用以鉴别伪品头花杯苋,其中2个可用以鉴别出掺混5%川牛膝,且9个特征峰的光谱图大多类似于皂苷类成分的末端吸收光谱图,表明头花杯苋可能含有大量皂苷类成分。以建立的川牛膝特征指纹图谱为参照,相似度分析得出川牛膝相似度均大于0.942,而头花杯苋、掺混川牛膝相似度分别小于0.383,0.399。聚类分析树状图和主成分得分三维图均能将川牛膝、头花杯苋、掺混川牛膝明显的分为3类。以上研究结果均表明川牛膝、头花杯苋、掺混川牛膝在化学组分上表现出明显的差异,当区别用药,不可混淆。

Cyathula capitate is the main adulterant of C. offinalis. According to the literature reported,there are obvious differences in properties,taste and pharmacological activity between C. capitate and C. offinalis. Therefore,C. capitate can only be used as a local conventional medicine and can＇t be a substitute for C. offinalis. Since the appearance of C. capitata is very similar to the C. offinalis and the content of cyasterone also can reach the limit of the current pharmacopoeia standard,the C. capitata is mostly sold in the form of impersonation oradmixture,which seriously affected the safety of the clinical medication and the development of the genuine crude drugs. In view of this,HPLC characteristic fingerprint was used to reveal the difference of multi-ingredients of C. offinalis,C. capitata and their admixture. According to the HPLC chromatogram of C. offinalis,C. capitata. and their admixture,65 different components were obtained to set up a peak area data matrix of 26 × 65,which was applied to perform the characteristic peak difference analysis,similarity analysis,hierarchical clustering analysis HCA and principal component analysis（ PCA）. Characteristic peak difference analysis showed that the characteristic peaks of C. capitata and their admixture are more and higher respond than those of C. offinalis.The 9 characteristic peaks were used to distinguish C. capitata,2 of which were used to distinguish C. offinalis mixed with 5% C.capitata. UV spectra of 9 characteristic peaks are mostly similar to the end absorption spectra of saponins,indicating that C. capitata may contain a large amount of saponins. By the reference fingerprint of C. offinalis established,the similarity analysis showed that the similarity degree of C. offinalis are higher than 0. 942,while the similarity degree of C. capitata,C. offinalis mixed with 5% C. capitata are less than 0. 383 and 0. 399. C. offinalis,C. capitata,C. offinalis mixed with 5% C. capitata could be obviously divided into3 classes by HCA and PCA. These results showed that there are obvious difference in the chemical composition of C. offinalis,C. capitata and their admixture,which could provide evidence for their identification.