The genus Hypericum comprises more than 450 species widely occurring in temperate regions and tropical highlands. Many species are used locally as traditional medicine against a variety of diseases. However, only a small proportion has been phytochemically characterized. The Common St. John’s wort (Hypericum perforatum L.) is a well-known medicinal herb used for the treatment of mild to moderate depressions. Prominent secondary metabolites include flavonoids, naphthodianthrones such as hypericin, and polyprenylated phloroglucinols such as hyperforin.
We developed untargeted metabolomic approaches to detect a high number of metabolites with different physical and chemical properties simultaneously. Metabolite profiles obtained by 1D and 2D NMR and MS were evaluated by multivariate data analysis and can be furthermore correlated with various bioassay results to identify the bioactive chemical constituents.
This approach was successfully applied to compare and evaluate commercial Hypericum preparations, to investigate the secondary metabolite diversity within the genus [1] or species and to select species or samples for the discovery of unknown natural products [2, 3]. Detailed investigation of species selected by this method resulted in the isolation and structure elucidation of approximately 30 novel natural products including compounds with promising anthelmintic or anti-HIV activities [2, 3].
Currently, comparative metabolite profiles of H. perforatum accessions with different genetic background are investigated to estimate the intraspecific variance. The results can be used to characterize breeding lines and to select genotypes with an optimized compound composition with respect to specific pharmacological applications.
References:
[1] Porzel A, Farag MA, Mülbradt J, Wessjohann LA. Metabolomics 2014; 10: 574-588.
[2] Fobofou SAT, Franke K, Porzel A, Brandt W, Wessjohann LA. J Nat Prod 2016; 79: 743-753.
[3] Fobofou SAT, Franke K, Sanna G, Porzel A, Bullita E, La Colla P, Wessjohann LA. Bioorg Med Chem 2015; 23: 6327-6334
Acknowledgements:
The Leibniz Association (SAW-2015-IPB-2), Saxony-Anhalt and EFRE (ZS/2016/05/78617) and the DAAD are acknowledged for financial support.