[Study on compatibility of Coptidis-Evodia couples by FTIR spectroscopy].

Combining unique macro-fingerprint characteristics of infrared spectroscopy (IR) with the overall concept of traditional Chinese medicine (TCM) theory, the authors seek to establish a new, rapid and economic method for research on Chinese herb preparation (CHP), which could reflect the whole and integration concept of TCM theory and also be widely applied in TCM research. In the present paper, four coptidis-evodia couples, e.g. Zuo-jin-wan (coptidis : evodia = 6 : 1), Gan-lu-san (coptidis : evodia = 2 : 1), Zhu-yu-wan (coptidis : evodia = 1 : 1) and Fan-zuo-jin (coptidis : evodia = 1 : 6), were extracted by boiling water and 80% alcohol, and the FTIR spectra of those CHPs were compared and analyzed in detail. The characteristic absorbance bands of coptidis and evodia were assigned in the FTIR spectra of the four coptidis-evodia couples. The results showed that rhizoma coptidis owns absolute superiority in both extracts of Zuo-jin-wan and Gan-lu-san since the proportions of rhizoma coptidis in the two couples are higher than those of fructus evodiae. With regard to Zhu-yu-wan, the proportions of two ingredients are the same. However, the contribution rate of coptidis is higher than that of evodiae in water extract of Zhu-yu-wan. In addition, coptidis also shows higher contribution rate than that of evodia in alcohol extract of Fan-zuo-jin. The spectroscopic technique described here is a simple and rapid analytical technique, which could provide valuable chemical information about the whole coptidis-evodia CHPs.