HPLC fingerprinting and pattern recognition of Brazilian green propolis and Chinese propolis

In order to improve the quality control method for propolis, HPLC fingerprinting and pattern recognition of 12 batches of Brazilian green propolis and 12 batches of Chinese propolis were carried out. HPLC fingerprinting was performed on a C18 column (250 mm × 4.6 mm, 5μm) using gradient elution with methanol-water (containing 0.2% formic acid) as the mobile phase. Similarity analysis was executed on similarity evaluation system for chromatographic fingerprint of TCM (2012A). Pattern recognition was performed by SIMCA-P 13.0 software. As a result, as for the two groups of propolis samples, 21 common peaks were calibrated and 11 of them were identified as chlorogenic acid, caffeic acid, isochlorogenic acid B, isochlorogenic acid C, quercetin, kaempferol, apigenin, pinocembrin, caffeic acid phenylethyl ester, galangin and artepillin C. The similarity of the fingerprint profiles of the tested Brazilian propolis is more than 0.92, and that of the tested Chinese propolis is more than 0.91. However, the two groups of fingerprints' similarity are from 0.523 to 0.693. The results of PCA and OPLS-DA showed that chemical profiles of the tested Brazilian green propolis were different from those of Chinese propolis. A set of compounds, namely, artepillin C, chlorogenic acid, pinocembrin, isochlorogenic acid B and caffeic acid phenylethyl ester can act as difference marker of the two groups of propolis. Moreover, HPLC fingerprint combined with pattern recognition could be developed into one new method for quality control of propolis.