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

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 into 3 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.