Comparative pharmacognosy and secondary metabolite analysis of Balanophorae herbs from different sources

The Balanophorae are not only traditional Chinese herbal medicines but also functional foods with diverse sources. This study aimed to distinguish pharmacognostic characteristics and secondary metabolites among different species of Balanophorae. Eight species of Balanophorae herbs were harvested, including 21 batches with 209 samples. Ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry was used to analyze secondary metabolites of Balanophorae from 21 sources. Targeted metabolomic analysis was performed to compare differences among the groups. Rhopalocnemis phalloide and B. indica can be identified by their pharmacognostic characteristics. Then, 41 secondary metabolites were identified or characterized in the mixed extracts of the 209 samples, mainly phenolic acids, flavonoids, and their derivatives. The distribution of these secondary metabolites revealed apparent differences among different species. In addition, targeted metabolomic analysis suggested that the secondary metabolite profiles of seven species of Balanophorae showed noticeable differences, and differences were also observed among different growing regions. Finally, five important metabolic markers were screened to successfully distinguish B. laxiflora, B. harlandii, and B. polyandra, including three phenolic acids and two flavonoids. This is the first study to systematically compare both the morphology and secondary metabolites among different sources of Balanophorae, which could provide effective information for identifying diverse species.