Phylogenetic and spatial patterns of herbal medicine compounds: Which medicinal plants are phytochemically characterized?

Objective

The study of phytometabolites of medicinal plants and their phylogenetic distribution is an important content of pharmacophylogeny. The objectives of this study were to provide an updated estimate of the extent to which the medicinal plants were investigated phytochemically and relate this to the species-level phylogeny and their geographical pattern.

Methods

Here, we further characterized 1 648 phytometabolites, including terpenoids, steroids, flavonoids, phenylpropanoids, phenolics, alkaloids, etc., reported in journals Chinese Traditional and Herbal Drugs (Zhong Cao Yao) and Chinese Herbal Medicines (CHM) from the phylogenetic and spatial perspectives. According to the structural characteristics, terpenoids, flavonoids, alkaloids and phenylpropanoids were subdivided into subclasses, and the research effort of phytometabolites was for the first time delineated at both subclass and phylogenetic levels.

Results

The phytometabolites of 90 families were reported on two journals in three years. It is noted that terpenoids with diverse bioactivities still constitute the primary object of phytochemical research, followed by flavonoids, phenolics, phenylpropanoids and alkaloids. Among the reported species, the family Asteraceae had the most, followed by Lamiaceae, Fabaceae, and Ranunculaceae. In the phylogenetic distribution of the reported phytometabolites, the net relatedness index (NRI) results revealed a clustered structure for triterpene, iridoid, flavone, flavonol, coumarin, indole alkaloid and terpenoid alkaloid, while the nearest taxon index (NTI) metric identified the clustered structure for triterpene, sesquiterpene, indole alkaloid and terpenoid alkaloid. Especially in Ranunculaceae, there were more reports on triterpene and terpenoid alkaloid subclasses. The overdispersion pattern of diterpene and phenolic was suggested by NRI and NTI respectively, albeit more reported diterpenes and phenolics were in Lamiaceae. The geographical distribution hotspots of reported species and compounds thereof highlighted the enormous progress of herbal medicine research and industry, which play a positive role in the future drug discovery and development.

Conclusion

These results provide new dimensions and perspectives in the context of pharmacophylogeny for perceiving and evaluating research trends and flashpoints in medicinal phytochemistry.