Partial degradation products (PDPs) of herbal medicine (HM) polysaccharides with precolumn derivatization using 1-phenyl-3-methy-5-pyrazolone (PMP) were mapped by high performance liquid chromatography (HPLC), and three groups of confusable HMs were differentiated using the PDP fingerprints assisted with cluster analysis (CA). Three variables of HPLC mobile phase, i.e. acetonitrile proportion, buffer concentration and pH value were optimized with PDP of β-cyclodextrin. Radix Glehniae and Radix Adenophorae; Radix Sophorae Tokinensis and Rhizoma Menispermi; Radix Achyranthis Bidentatae and Radix Cyathulae were successfully distinguished by the method, respectively. The results involving mass spectrometry analysis showed that these PDPs primarily included oligosaccharides and a few monosaccharides. The method can be used as an effective approach for the identification and quality control of HMs, and can also facilitate the in-depth study of biological activity and further development of HM polysaccharides to some extent.
Keywords: Confusable herbal medicine; HPLC; cluster analysis; identification; partial degradation products; polysaccharide.