HPLC fingerprints combined with principal component analysis, hierarchical cluster analysis and linear discriminant analysis for the classification and differentiation of Peganum sp. indigenous to China

Abstract

Introduction – Seeds of wild <i>Peganum harmala</i> Linn., <i>P. multisectum</i> (Maxim) Bobr., <i>P. nigellastrum</i> Bunge and a probable indeterminate species, herein referred to as <i>P.</i> variety, are commonly used in Chinese medicine. These seeds cannot be differentiated based on morphology.

Objective – Seeds of <i>P. harmala</i> Linn., <i>P. multisectum</i> (Maxim) Bobr., <i>P. nigellastrum</i> Bunge and <i>P.</i> variety were collected in different provinces in China and their HPLC profiles were recorded for statistical analysis and pattern recognition.

Methodology – HPLC chromatograms of seed extracts were recorded under the same conditions. Individual HPLC chromatograms for each species were evaluated against the mean chromatogram for the same species generated using a similarity evaluation computer program. Data from chromatographic fingerprints were also processed using principal component analysis (PCA), hierarchical cluster analysis (HCA) and linear discriminant analysis (LDA).

Results – The <i>Peganum</i> sp. seed extracts had similar HPLC fingerprints but with some inter-specific differences. The chromatographic fingerprints combined with PCA, HCA and LDA could distinguish the seeds of the different species of <i>Peganum</i> investigated.

Conclusion – HPLC fingerprints can be used to authenticate and differentiate the seeds of three different species of genus <i>Peganum</i> indigenous to China. The results indicated that the unidentified <i>P.</i> variety might indeed be a new species or variety.