Phloroglucinol derivatives from Hypericum species induce in vitro proliferation of cells involved in the wound healing process

Hypericum Genus as a Natural Source for Biologically Active Compounds

Hypericum L. genus plants are distributed worldwide, with numerous species identified throughout all continents, except Antarctica. These plant species are currently used in various systems of traditional medicine to treat mild depression, wounds and burns, diarrhea, pain, fevers, and their secondary metabolites previously shown, and the in vitro and/or in vivo cytotoxic, antimicrobial, anti-inflammatory, antioxidant, antihyperglycemic, and hepatoprotective activities, as well as the acetylcholinesterase and monoamine oxidase inhibitory activities. We conducted a systematic bibliographic search according to the Cochrane Collaboration guidelines to answer the question: "What is known about plants of Hypericum genus as a source of natural products with potential clinical biological activity?" We documented 414 different natural products with confirmed in vitro/in vivo biological activities, and 58 different Hypericum plant species as sources for these natural products. Phloroglucinols, acylphloroglucinols, xanthones, and benzophenones were the main chemical classes identified. The selective cytotoxicity against tumor cells, cell protection, anti-inflammatory, antimicrobial, antidepressant, anti-Alzheimer's, and adipogenesis-inhibition biological activities are described. Acylphloroglucinols were the most frequent compounds with anticancer and cell-protection mechanisms. To date, no work has been published with a full descriptive list directly relating secondary metabolites to their species of origin, plant parts used, extraction methodologies, mechanisms of action, and biological activities.

An Integrated LC-ESI-MSn and High Resolution LC-ESI-QTOF Approach for the Identification of Phloroglucinols from Nepalese Hypericum japonicum

Phloroglucinols are characteristic constituents of Hypericumjaponicum that are claimed to exert several bioactivities, such as anti-inflammatory, anti-depressant and anti-viral ones. Phloroglucinols are unstable compounds and their synthesis is challenging; thus, isolation from natural sources is still one of the main strategies for obtaining these constituents in purified form. Assessing the presence of phloroglucinols in plant materials can be of interest for compound isolation, and LC-MS approaches afford sensitivity and specificity in this regard. In this work, we combined data from quadrupole-time of flight (QTOF) and ion trap (IT) mass spectrometers in order to assess the presence of the phloroglucinols characteristic of H. japonicum and to elucidate their MS fragmentation pathways. The identified compounds present similar structures bearing the 1,3,5-trihydroxybenzene core with different substitutions, which, in constituents at higher MW, is linked to 3',3'-dimethyl-6'-oxo-phlorisobutyrophenone by a methylene bridge. Differences in MS² spectra of the considered phloroglucinols are useful for compound identification and differentiation, and to perform dereplication studies. Overall, the proposed approach could be useful for the analysis of phloroglucinols in H. japonicum and other plant species.