Comparative analysis of genetic and chemical differences between four Berberis herbs based on molecular phylogenetic and HPLC methods.

In traditional Tibetan medicinal system, Berberis herbs mainly originate from the dried barks of Berberis kansuensis, Berberis dictyophylla, Berberis diaphana, and Berberis vernae. In this study, molecular phylogenetic method based on four markers (i.e., rbcL, internal transcribed spacer (ITS), ITS2, and psbA-trnH) and HPLC chemical analysis were used to evaluate the chemical and genetic differences between the four Berberis species. The results showed that the discriminatory power of ITS, ITS2 and psbA-trnH was low, but the rbcL marker was highly effective and reliable for the species differentiation. The four Berberis species can be successfully classified based on phylogenetic analysis of the rbcL sequences. Moreover, the results of chemical analysis showed that four main alkaloids (i.e., berberine, palmatine, magnoflorine, and jatror-rhizine) cannot be used as chemical markers for discrimination of the four Berberis species. These findings provide valuable information for distinguishing the four Berberis Tibetan herbs.