Abstract:

An efficient and simple pattern recognition methodrelative peak area difference (ΔSr) grade sequence classifying method was established. It is suitable for analyzing HPLC fingerprint spectra of herbal medicines Buzhong Yiqi Pills and Shiquan Dabu pills based on both information of peak positions and contents of compounds, and it is qualified to recognize the two traditional Chinese compound formulae which are so-called “black box” systems. The HPLC fingerprint spectra of these two medicines’ components extracted with absolute ethanol were measured, and the ΔSr sequences of these samples were constructed. Then their most similar sample groups characteristic sequences named ΔSr grade sequences were determined depending on the similarity scale ΔSr≤ΔSr+xSv,-3≤x≤+3. In addition, clustering and classification of these samples were performed relying on the characteristic sequences. These two kinds of  medicine were accurately and subtly recognized by this new method, with the correct ratio of 100％. The results were greatly superior to those  obtained by means of coefficient r and vectorial angle cosine(cosα) methods. The results also indicated that the ΔSr grade sequence clustering／classifying method was an accurate and simple approach suitable for quantitative identification and quality control of traditional Chinese compound formula, a kind of complex “black box” system.

Key words: Buzhong Yiqi Pill, Shiquan Dabu Pill, fingerprint spectra, ΔSr grade sequence, identification, pattern recognition, black box