Understanding the biological activity of Hypericum species through metabolomics studies

In this paper we characterize the metabolic fingerprint and first reported antiinflammatory activity of Hypericum gentianoides. H. gentianoides has a history of medical use by Native Americans, but it has been studied very little for biological activity. High-performance liquid chromatography (HPLC) and liquid chromatographyelectrospray ionization-mass spectrometry (LC-ESI-MS) analyses of a methanol extract show that H. gentianoides contains a family of over nine related compounds that have retention times, mass spectra, and a distinctive UV absorption spectra characteristic of certain acyl-phloroglucinols. These metabolites are abundant relative to other secondary products present in H. gentianoides accounting for approximately 0.2 grams per gram of dry plant tissue. H. gentianoides methanol extracts and a specific semi-preparative HPLC fraction from these extracts containing the putative acyl-phloroglucinols, reduce prostaglandin E2 synthesis in mammalian macrophages. Introduction The Hypericum genus contains over 450 species; the 75 to 80 species that have been surveyed for phytochemicals to date are rich in secondary metabolites such as type * To whom correspondence should be addressed: Tel: (515) 294-3509. E-mail: [email protected] or [email protected] † Center for Research on Botanical Dietary Supplements ‡ Department of Genetics, Development, and Cell Biology at Iowa State University # Department of Food Science and Human Nutrition at Iowa State University