Chemical markers of four species of Epimedium used in drug Yin-Yang-Huo

摘要

There are four species of Epimedium that have been officially adopted in Chinese Pharmacopoeia (2015) under the same crude drug name 'Yin-Yang-Huo', including E. brevicornu Maxim., E. koreanum Nakai., E. sagittatum (Sieb.et Zucc.) and E. pubescens Maxim. This study aimed to identify the chemical markers of these species by HPLC-PDA fingerprinting combined with chemometrics methods. The HPLC separation was performed on a Water's Atlantis (R) T3 column (4.6 x 250 mm, 5 mu m) with the gradient elution of acetonitrile-0.1% formic acid aqueous solution using a PDA detector. The HPLC-PDA fingerprints of 88 batches of Yin-Yang-Huo samples were obtained and analysed using principal component analysis (PCA) and hierarchical cluster analysis (HCA). Samples of E. koreanum and E. sagittatum were classified into separate groups, while samples of E. brevicornum and E. pubescens were clustered together. Based on partial least squares-discriminant analysis (PLS-DA) and variable importance in projection, nine potential chemical markers were discovered, and six markers were identified by comparing with reference standards or according to their MS/MS fragmentation behaviour. Among them, korepimedoside C and epimedokoreanoside I could be used as chemical markers of E. koreanum to differentiate it from the other three species, while epimedin B1 and epimedin A1 could be used as chemical markers of E. sagittatum. This study will help effectively distinguish different Yin-Yang-Huo species and provide a valuable strategy for analysing the potential chemical markers of herbal medicines with multiple botanical origins.