Dearomatized Isoprenylated Acylphloroglucinol Derivatives with Potential Antitumor Activities from Hypericum henryi

Comprehensive Metabolite Profiling of Two Edible Garcinia Species Based on UPLC-ESI-QTOF-MSE Coupled with Bioactivity Assays

In China, the endemic species Garcinia yunnanensis and native Garcinia xanthochymus are known as edible and medicinal plants. However, a systematic metabolomic and bioactivity evaluation of different plant parts from both species is lacking. In this study, comprehensive investigations of 11 plant parts of G. yunnanensis and 10 of G. xanthochymus employing UPLC-ESI-QTOF-MS^E-based metabolomic analysis in conjunction with three bioactivity assays were undertaken. A customized chemotaxonomic-based in-house library containing 6456 compounds was constructed and coupled to the Progenesis QI informatic platform for metabolite annotations. From these two species, a total of 235 constituents were characterized using multiple criteria. Differences in metabolite profiles between the plant parts within each species were uncovered using multivariate analysis. Based on orthogonal partial least-squares discriminant analysis (OPLS-DA), 23 markers were identified as highly differential metabolites from G. xanthochymus and 20 from G. yunnanensis. Comparative assessment of the biological assays revealed the activity variations among different plant parts. The seeds of both species and G. yunnanensis latex exhibited excellent cytotoxic and antibacterial activities, while G. xanthochymus roots and G. yunnanensis arils showed strong anti-inflammatory effects. S-plot analysis identified 26 potential biomarkers for the observed activities, including the known cytotoxic agent cycloxanthochymol and the anti-inflammatory compound garcimultiflorone B, which likely explains some of the potent observed bioactivity.

Hyperxylones A and B, two polycyclic polyprenylated acylphloroglucinols with a benzoyl substituted bicyclo[3.2.1]octane core from Hypericum beanii

Two new polycyclic polyprenylated acylphloroglucinols (PPAPs) possessing a rare benzoyl substituted bicyclo[3.2.1]octane core, hyperxylones A (1) and B (2), along with three new dearomatized isoprenylated acylphloroglucinols (DIAPs), hyperxylones C - E (3-5), were isolated from the roots of Hypericum beanii. The structures of 1-5 were determined by high-resolution electrospray ionization mass spectroscopy (HRESIMS) and 1D/2D nuclear magnetic resonance (NMR) spectroscopic analyses, gauge-independent atomic orbital (GIAO) NMR calculations, and electronic circular dichroism (ECD) calculations. Compounds 1 and 2 were biomimetically semi-synthesized starting from 5 and 4, respectively, enabling the correct stereochemical assignment of 5 and 4. Moreover, compounds 1 and 2 showed anti-nonalcoholic steatohepatitis (NASH) activity by inhibiting lipid deposition in L02 cells; compounds 3 and 5 exhibited nitric oxide (NO) inhibitory activity in lipopolysaccharides (LPS)-induced RAW264.7 cells.

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.

Discovery of dearomatized isoprenylated acylphloroglucinols with colon tumor suppressive activities in mice via inhibiting NFκB-FAT1-PDCD4 signaling activation

Dearomatized isoprenylated acylphloroglucinols (DIAPs) are specific natural products mainly distributed in the plants of genus Hypericum. In this study, guided by HPLC-UV screening, 46 DIAPs (approximately 70% of all DIAPs) including 20 new ones and an unprecedented architecture, were discovered from the roots of Hypericum henryi, which were elucidated by comprehensive spectroscopic, X-ray crystallography, and ECD methods. Compounds 1-7, 39, and 41-42 exhibited remarkable cytotoxicities (IC₅₀ = 0.84-5.63 μM) in human colon cancer HCT116 cells, in which 2 and 6 possessed selective cytotoxicities towards colon cancer cells. The preliminary structure-activity relationships of these tested compounds were discussed. In addition, mechanistic investigations demonstrated that 2 and 6 could significantly suppress the expressions of NFκB, FAT1, and promoted novel tumor suppressor gene PDCD4 in HCT116 cells. Furthermore, in HCT116 colon xenograft-bearing mouse model, treatments with 2 and 6 reduced the growth of xenograft tumors in dose-dependent manner. Expressions of FAT1 in tumors were also decreased in mice treated with 2 and 6, suggesting their anti-tumor effects were via FAT1 signaling pathway. In conclusion, this is the first report on the mechanistic and in vivo studies of DIAP, indicating that these metabolites can be considered as a new type of anti-colon cancer lead agents for further drug development.

Diverse Polycyclic Polyprenylated Acylphloroglucinol Congeners with Anti-Nonalcoholic Steatohepatitis Activity from Hypericum forrestii

The new polycyclic polyprenylated acylphloroglucinols, hyperforcinols A-J (1-10), were isolated from the fruits of Hypericum forrestii, together with 30 biogenetic congeners of known structures. The structures of hyperforcinols A-J were determined by HRESIMS and 1D/2D NMR spectroscopic analysis, and their absolute configurations were determined by a combination of the electronic circular dichroism (ECD) exciton chirality method, ECD calculations, and X-ray diffraction analysis. A selection of 25 isolates, possessing seven types of carbon skeletons, were assessed for their in vitro effects against nonalcoholic steatohepatitis (NASH) using a free fatty acid-induced L02 cell model. Compounds 20 and 40 significantly decreased intracellular lipid accumulation. QRT-PCR analyses revealed that compounds 20 and 40 regulate the expression of lipid metabolism-related genes, including CD36, FASN, PPARα, and ACOX1.

Novel Meroterpenoids from Hypericum patulum: Highly Potent Late Nav1.5 Sodium Current Inhibitors

Hypulatones A and B (1 and 2), two racemic meroterpenoids possessing an unprecedented spiro[benzofuran-2,1'-cycloundecan]-4'-ene-4,6(5H)-dione core, were characterized from Hypericum patulum. Compound 2 was found to significantly inhibit the late current of Na_v1.5 (late I_Na, IC₅₀ = 0.2 μM). Importantly, 2 exhibited remarkable separation (>100-fold) of late I_Na relative to peak I_Na and notable selectivity over Ca_v3.1, K_v1.5, and hERG. 1 showed comparable inhibition on late I_Na compared to that of 2 with poorer selectivity.