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Fifteen undescribed phenylpropanoyl phloroglucinol derivatives featuring modified isoprenyl and/or geranyl units (1-15), in conjunction with thirteen known analogues (16-28), were obtained from the glandular hairs of the fruit of Mallotus philippensis. Meanwhile, fourteen pairs of new enantiomers [(±)-1-9, (±)-11-15] were further resolved by chiral purification. Their structures were determined by comprehensive spectroscopic analyses, single-crystal X-ray diffraction experiments and quantum chemical calculations. Bioactivity evaluation showed that compound 17 exhibited significant anti-bacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) with MIC of 6 μg/mL, while compounds 3, 4, 8 and 18 displayed moderate effects with MIC of 24, 12, 24, and 12 μg/mL, respectively. The KEGG enrichment analysis of 17 revealed that the phosphotransferase system (PTS) pathway was significantly enriched. In addition, compound 17 was found to affect the amino acids biosynthesis and amino acids/carbohydrate metabolism, and the qRT-PCR verified the accuracy of the transcriptome analysis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Garciyunnanol A (1), an unprecedented 1,2-seco-bicyclic polyprenylated acylphloroglucinol (BPAP) possessing a unique 6/6/6 tricyclic core, was characterized from Garcinia yunnanensis together with 16 BPAPs, including eight new compounds (garciyunnanols B-I, 2-9). Biogenetically, the bicyclo[3.3.1]nonane-2,4,9-trione moiety of 12 reconstructed the bicyclic δ-lactone core of 2 through Norrish type Ⅰ cleavage and cyclization, followed by a cyclization of two side chains to form an intriguing 6/6/6 tricyclic core of 1. Their structures were elucidated through analysis of spectroscopic data, calculation and comparison of ECD spectra. Bioactivity evaluation manifested that compounds 1, 2, 5, 6 and 14 demonstrated superior inhibition of NO production compared to the positive control dexamethasone. Notably, compound 5 exhibited a dose-dependent inhibitory effect on NO production, with an IC 50 value of 0.25 ± 0.87 µM. Furthermore, experiments involving ELISA, Western blotting, and immunofluorescence staining revealed that 5 effectively reduced the secretion of interleukin-1β in LPS plus nigericin-stimulated THP-1 macrophages by inhibiting the activation of the NLRP3 inflammasome., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

The phytochemical investigation on the pericarps of Garcinia multiflora resulted in the isolation of 12 previously undescribed polycyclic polyprenylated acylphloroglucinols (PPAPs, 1-12) with a variety of skeletons. Their structures were determined by comprehensive spectroscopic analyses, ECD calculations, and single-crystal X-ray diffraction. Compounds 6-9 possess a rare bicyclo[4.3.1]decane skeleton. Additionally, the anti-tumor activity of the 12 isolates was evaluated. The results indicated that compounds 5, 9, and 12 exhibited significant cytotoxicity in a wide range of cancer cell lines, including the human breast cancer MDA-MB-231 cells, human lung cancer A549 cells, human colon cancer SW480 cells and human ovarian cancer HEY cells. Further studies indicated that compound 5 induced cell cycle arrest and apoptosis, to inhibit the growth of MDA-MB-231 cells. Taken together, these findings expand the chemical diversity of PPAPs and further demonstrate the potential of PPAPs as candidates for cancer treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Three new acylphloroglucinols were isolated from the branches and leaves of Hypericum perforatum L., named as hyperipersions A-C ( 1-3 ), together with three known compounds which were identified as elegaphenone ( 4 ), 2,6-dihydroxy-3,4-dimethylbenzoic acid methyl ester ( 5 ) and 2,3-methylenedioxyxanthone ( 6 ), respectively. The structures of isolated compounds were determined by UV, IR, HR-ESI-MS, NMR analysis. Their antiangiogenic activities were studied against HUVECs. The IC 50 value of compound 3 was 2.39 ± 0.21  μ M against HUVECs, which was stronger than vatalanib, and other compounds had moderate antiangiogenic activity.

Four previously undescribed phloroglucinols, including three pairs of enantiomers, (±)-rhodotomentodimer F, (±)-rhodotomentodimer G, and (±)-rhodotomentomonomer E, and one phloroglucinol-sesquiterpene meroterpenoid, rhodotomentodione E, together with one previously reported congener, (±)-rhodomyrtosone A, were obtained from the leaves of Rhodomyrtus tomentosa. The structures including absolute configurations of previously undescribed isolates were elucidated by extensive spectroscopic analysis (HRESIMS and NMR), ECD calculations, and single-crystal X-ray diffraction. (±)-Rhodotomentodimer F is a rare phloroglucinol derivative conjugated by a β-triketone moiety and an unprecedented resorcinol unit via the formation of a rare bis-furan ring system, whereas (±)-rhodotomentomonomer E shares a rearranged pentacyclic scaffold. Pharmacologically, (±)-rhodotomentomonomer E showed the strongest human acetylcholinesterase (hAChE) inhibitory effect with an IC 50 value of 1.04 ± 0.05 μM. Molecular formula studies revealed that hydrogen bonds formed between hAChE residues Glu202, Ser203, Ala204, Gly121, Gly122, Tyr337, and His447 and (±)-rhodotomentomonomer E played crucial roles in its observed activity. These findings indicated that the leaves of Rhodomyrtus tomentosa can supply a rich source of hAChE inhibitors. These inhibitors might potentially be utilized in the therapeutic strategy for Alzheimer's disease, offering promising candidates for further research and development., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Six new polycyclic polyprenylated acylphloroglucinols (PPAPs), hyperidiones A-F (1-6), were obtained from Hypericum perforatum L. Their structures were characterized via extensive spectroscopic analyses, the circular dichroism data of the in situ formed [Mo 2 (OCOCH 3 ) 4 ] complexes, the nuclear magnetic resonance calculation with DP4 + probability analysis, and the calculated electronic circular dichroism (ECD) spectra. Compounds 1-6 are bicyclic polyprenylated acylphloroglucinols with a major bicyclo[3.3.1]nonane-2,4,9-trione skeleton. Notably, compound 1 is a rare PPAP with a hydroperoxy group, and a plausible biosynthetic pathway for 1 was proposed. Compounds 4 and 6 exhibited significant neuroprotective effects under 10 μM against corticosterone (CORT)-injured SH-SY5Y cells. Furthermore, compound 4 demonstrated a noteworthy antidepressant effect at the dose of 5 mg/kg in the tail suspension test (TST) of mice, which was equivalent to 5 mg/kg of fluoxetine. And it potentially exerted an antidepressant effect through the hypothalamic-pituitary-adrenal (HPA) axis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Garciyunnanones A-R (1-18), eighteen undescribed caged polycyclic polyprenylated acylphloroglucinols, two undescribed biogenetic congeners (19-20), and nineteen known analogues (21-39), were isolated from the stem barks of Garcinia yunnanensis Hu. All of these isolates are decorated with a C-5 lavandulyl substituent. Their structures and absolute configurations were confirmed by HRESIMS, 1D & 2D NMR spectroscopic analysis, quantum chemical calculations of electronic circular dichroism data, and single-crystal X-ray diffraction analysis. The X-ray crystallographic data of ten isolated caged compounds ascertained the absolute configuration of C-23 in the lavandulyl as S. The cytotoxicity on three cancer cell lines and the anti-nonalcoholic steatohepatitis activity of the isolates were tested. In a free fatty acid-induced L02 cell model, compounds 33 and 39 decreased intracellular lipid accumulation significantly., Competing Interests: Declaration of competing interest All authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Seven pairs of undescribed monoterpenoid polyprenylated acylphloroglucinol enantiomers [(±)-hypermonanones A-G (1-7)], together with three known analogues, were identified from the whole plant of Hypericum monanthemum Hook. The structures of these compounds were determined by analyses of their UV, HRESIMS, 1D/2D NMR spectroscopic data, and NMR calculations. The absolute configurations of these compounds were assigned by ECD calculations after chiral HPLC separation. Diverse monoterpene moieties were fused at C-3/C-4 of the dearomatized acylphloroglucinol core, which led to 3,4-dihydro-2H-pyran-integrated angular or linear type 6/6/6 tricyclic skeletons in 1-7. Compounds (-)-2 and (+)-2 exhibited significant NO inhibitory activity against LPS induced RAW264.7 cells with the IC 50 values of 7.07 ± 1.02 μM and 11.39 ± 0.24 μM, respectively., Competing Interests: Declaration of competing interest All authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Patumantanes A-D ( 1 - 4 ), four new seco -polycyclic polyprenylated acylphloroglucinols (PPAPs) were isolated from Hypericum patulum . Patumantane A ( 1 ) was an unprecedented 1,2- seco -homoadamantane-type PPAP bearing a new 3,7-dioxatetracyclo[7.7.0.0 1,6 .1 11,15 ]heptadecane architecture based on a 6/7/5/6 ring system. Patumantane B ( 2 ) was a unique 1,9- seco -adamantane-type PPAP with a tricyclo[4.4.4.0.0 2,12 ]tridecane core formed by a 6/6/6 carbon skeleton, and the further breakage between C-5 and C-9 decorated patumantane C ( 3 ) with the 9- nor -adamantane skeleton. More importantly, compounds 2 and 3 exhibited moderate immunosuppressive activity on Con A-induced T-lymphocyte proliferation in vitro , with IC 50 values of 5.6 ± 1.2 and 11.2 ± 1.2 μM, respectively.

Many polyprenylated acylphloroglucinols with fascinating chemical structures and intriguing biological activities have been identified as key to phytochemicals isolated from Garcinia, Hypericum , and related genera. In the present work, two chiral, tautomeric, highly-oxygenated polyprenylated acylphloroglucinols tethered with acyl and prenyl moieties on a bicyclo[3.3.1]nonanetrione core were isolated from the 95% ethanolic extract of Garcinia gummi-gutta fruit. The structures of both compounds were elucidated based on the NMR and MS data with ambiguity in the exact position of the enol and keto functions at C-1 and C-3 of the core structure. The structures of both polyprenylated acylphloroglucinols were established as a structurally revised guttiferone J and the new iso -guttiferone J with the aid of gauge-independent atomic orbital NMR calculations, CP3 probability analyses, specific rotation calculations, and electronic circular dichroism calculations in combination with the experimental data. The structures of both compounds resemble hyperforin, a potent activator of the human pregnane X receptor. As expected, both compounds showed strong pregnane X receptor activation at 10 µM [7.1-fold (guttiferone J) and 5.0-fold ( iso -guttiferone J)], explained by a molecular docking study, necessitating further in-depth investigation to substantiate the herb-drug interaction potential of G. gummi-gutta upon co-administration with pharmaceutical drugs., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Hyperforatums A-D ( 1 - 4 ), four new polyprenylated acylphloroglucinols, together with 13 known compounds were isolated and identified from the aerial parts of Hypericum perforatum L. (St. John's wort). Their structures were confirmed with a comprehensive analysis comprising spectroscopic methods, including 1D and 2D NMR, HRESIMS, and electronic circular dichroism (ECD) calculations. Hyperforatum A featured an unusual chromene-1,4-dione bicyclic system, and hyperforatums B and C were two rare monocyclic PPAPs with five-membered furanone cores. Compound 1 exhibited a moderate inhibition effect on NO production in BV-2 microglial cells stimulated by LPS.

St. John's wort is an herb, long used in folk medicine for the treatment of mild depression. Its antidepressant constituent, hyperforin, has properties such as chemical instability and induction of drug-drug interactions that preclude its use for individual pharmacotherapies. Here we identify the transient receptor potential canonical 6 channel (TRPC6) as a druggable target to control anxious and depressive behavior and as a requirement for hyperforin antidepressant action. We demonstrate that TRPC6 deficiency in mice not only results in anxious and depressive behavior, but also reduces excitability of hippocampal CA1 pyramidal neurons and dentate gyrus granule cells. Using electrophysiology and targeted mutagenesis, we show that hyperforin activates the channel via a specific binding motif at TRPC6. We performed an analysis of hyperforin action to develop a new antidepressant drug that uses the same TRPC6 target mechanism for its antidepressant action. We synthesized the hyperforin analog Hyp13, which shows similar binding to TRPC6 and recapitulates TRPC6-dependent anxiolytic and antidepressant effects in mice. Hyp13 does not activate pregnan-X-receptor (PXR) and thereby loses the potential to induce drug-drug interactions. This may provide a new approach to develop better treatments for depression, since depression remains one of the most treatment-resistant mental disorders, warranting the development of effective drugs based on naturally occurring compounds., (© 2022. The Author(s).)

Spihyperglucinols A (1) and B (2), the first 13,15- nor -polycyclic polyprenylated acylphloroglucinols (PPAPs) featuring a 7/6/5 tricyclic ring system based on an unexpected bicyclo[3.2.2]nonane core, along with three new congeners, spihyperglucinols C-E (3-5), were isolated from Hypericum longistylum . Importantly, 1 and 2 displayed potential inhibitory effects on the production of nitric oxide in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages, with IC 50 values of (8.70 ± 1.18) and (9.23 ± 1.26) μM, respectively, comparable to the positive control, dexamethasone, with an IC 50 value of (9.76 ± 1.13) μM.

Twenty-four racemic acylphloroglucinol meroterpenoids including eighteen unusual stuctures (3 ∼ 10, 13, 14, and 17 ∼ 24), and a major component filixic acid ABA (25), were isolated from Dryopteris crassirhizoma. Structurally, the dimeric acylphloroglucinol derivatives possess unprecedented skeletons of mixed acylphloroglucinol and sesquiterpene biosynthetic origin. The stereochemistries of six reported meroterpenoids with undefined chiral centers were reassigned. Two intriguing methods by analyzing a) the regularity of chemical shift variation of protons and carbons around the stereogenic centers, and b) pyridine-induced deshielding effect of hydroxy groups, to discriminate relative configurations of flexible long-chain alcohol with chiral centers separated by three or seven covalent bonds, were successfully applied. A non-enzymatic biosynthesis of 1 ∼ 24 was assumed based on a rare single-crystal cluster formed with two diastereomeric enantiomer pairs (±1/±2) and chiral HPLC analyses. Meroterpenoids 13 and 14 showed obvious inhibitory effects on NO production in LPS-induced RAW264.7, and suppressed the expression of iNOS, COX-2, IL-1β, and IL-18. Their anti-inflammatory activity was closely related to the inhibition of the formation and function of inflammasomes. Additionally, the known 25 showed antiviral efficacy against the influenza viruse A/Puerto Rico/8/1934 (H1N1)., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Alzheimer's disease (AD) diagnoses are greatly increasing in frequency as the global population ages, highlighting an urgent need for new anti-AD strategies. With the aim to search for human acetylcholinesterase (hAChE) inhibitors from the species of Myrtaceae family, ten acylphloroglucinol trimers (APTs), including eight new APTs, callistemontrimers A-H (1a, 1b, 2a, 2b, 3a, 3b, 4b, and 5b), and two naturally occurring ones (4a and 5a), along with one reported triketone-acylphloroglucinol-monoterpene adduct (6), were obtained and structurally characterized from the hAChE inhibitory acetone extract of Callistemon salignus seeds. The structures and their absolute configurations for new APTs were unequivocally established via the detailed interpretation of extensive spectroscopic data (HRESIMS and NMR), ECD calculations, and single crystal X-ray diffraction, whereas the absolute configurations of known APTs were determined by further chiral separation, and calculated ECD calculations. The results of hAChE inhibitory assay revealed that an enantiomeric mixture of 2a/2b, 2a, and 2b are good hAChE inhibitors with IC 50 values of 1.22 ± 0.23, 2.28 ± 0.19, and 4.96 ± 0.39 μM, respectively. Molecular docking was used to uncover the modes of interactions for bioactive compounds with the active site of hAChE. In addition, 2 and 6 displayed moderate neurite outgrowth-promoting effects with differentiation rates of 6.16% and 6.19% at a concentration of 1.0 μM, respectively., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Five new spirocyclic polycyclic polyprenylated acylphloroglucinols, Hyperpatulones C-G (1-5), were obtained from the leaves of Hypericum patulum. Their structures were characterized by the comprehensive analysis of their IR, NMR, CD spectra and HRESIMS data. All the new compounds were evaluated for the α-glycosidase inhibitory activities. Among them, compounds 3-5 showed α-glucosidase inhibitory activities, with IC 50 values of 14.06-37.69 μM., (Copyright © 2021. Published by Elsevier B.V.)

Five new dimeric phloroglucinol derivatives, agrimones A - E (1-5), were isolated from the whole plant of Agrimonia pilosa. Their structures including absolute configurations were determined by a series of spectroscopic data (UV, IR, HR-ESI-MS, 1D and 2D NMR), complemented with the comparison of the experimental and calculated ECD spectra, and gauge-independent atomic orbital (GIAO) NMR calculations. Notably, compounds 1 and 2 represent a highly oxidized 6/6/6 tricyclic ring skeleton based on the cis-fused paraquinone and chroman. Compounds 1a, 4, and 5 exhibited moderate hepatoprotective activities against APAP-induced HepG2 cell injury at 10 μM., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Eucalyptus is a large genus of the Myrtaceae family with high value in various fields of industry. Recently, attention has been focused on the functional properties of Eucalyptus extracts. These extracts have been traditionally used to combat various infectious diseases, and volatile oils are usually considered to play a major role. But the positive effects of non-volatile acylphloroglucinols, a class of specialized metabolites with relatively high content in Eucalyptus, should not be neglected. Herein, non-volatile acylphloroglucinols from leaves of Eucalyptus robusta were evaluated for their abilities to inhibit Zika virus (ZIKV) which is associated with severe neurological damage and complications. The results showed eucalyprobusone G, a new symmetrical acylphloroglucinol dimer, possessed the significant ability to inhibit ZIKV without inducing cytotoxicity. The EC 50 values of eucalyprobusone G against the African lineage (MR766) and Asian lineage (SZ-WIV01) of ZIKV were 0.43 ± 0.08 and 10.10 ± 3.84 μM which were 110 times and 5.8 times better than those of the reference compound ribavirin, respectively. Further action mode research showed that eucalyprobusone G impairs the viral binding and RdRp activity of NS5. The results broaden the functional properties of Eucalyptus robusta and indicate acylphloroglucinol dimers could be developed as anti-ZIKV agents., (Copyright © 2021 Elsevier Inc. All rights reserved.)

By various chromatographic methods, 30 phloroglucinols (1-30) were isolated from a methanol extract of Dryopteris crassirhizoma, including two new dimeric phloroglucinols (13 and 25). The structures of the isolates were confirmed by HR-MS, 1D, and 2D NMR as well as by comparison with the literature. The protein tyrosine phosphatase 1B (PTP1B) effects of the isolated compounds (1-30) were evaluated using sodium orthovanadate and ursolic acid as a positive control. Among them, trimeric phloroglucinols 26-28 significantly exhibited the PTP1B inhibitory effects with the IC 50 values of 1.19 ± 0.13, 1.00 ± 0.04, 1.23 ± 0.05 μM, respectively. In addition, the kinetic analysis revealed compounds 26-28 acted as competitive inhibitors against PTP1B enzyme with K i values of 0.63, 0.61, 1.57 μM, respectively. Molecular docking simulations were performed to demonstrate that these active compounds can bind with the catalytic sites of PTP1B with negative binding energies and the results are in accordance with that of the kinetic studies. In vitro and in silico results suggest that D. crassirhizoma rhizomes together with compounds 26-28 are potential candidates for treating type 2 diabetes., (Copyright © 2021. Published by Elsevier B.V.)

Eleven new polycyclic polyprenylated acylphloroglucinols (PPAPs), hyperwilsones A-K (1-11), along with five known PPAPs (12-16), were isolated from Hypericum wilsonii. Their structures were established via spectroscopic methods, the careful analysis of calculated and experimental electronic circular dichroism (ECD) spectra, single-crystal X-ray diffraction, the modified Mosher's method, and [Rh 2 (OCOCF 3 ) 4 ]-induced ECD. Hyperwilsone A (1) and hyperwilsone B (2) possessed the unique acetal functionality. Hyperwilsone C (3) was a rare example of [3.3.1]-type PPAP possessing a 3-isopropylfuran moiety. In bioassay, compounds 9 and 10 showed potent anti-inflammatory activity against LPS-induced NO production by inhibiting the nuclear translocation of NF-κB p65 and thus reducing the production of proinflammatory cytokines. Compounds 5, 8, 11, and 14 exhibited moderate inhibitory activity against SUDHL-4 and HL60 cancer cells with IC 50 values in the range of 5.74-19.82 μM., (Copyright © 2021 Elsevier Inc. All rights reserved.)

α-Hemolysin (Hla) is an extracellular protein secreted by methicillin-resistant Staphylococcus aureus (MRSA) strains that plays a critical role in the pathogenesis of pulmonary, intraperitoneal, intramammary, and corneal infections, rendering Hla a potential therapeutic target. In this study, 10 unreported polycyclic polyprenylated acylphloroglucinol (PPAP) derivatives, garciyunnanins C-L (1-10), with diverse skeletons, were isolated from Garcinia yunnanensis Hu. The structures of these new compounds were determined by HRMS, NMR, electronic circular dichroism (ECD) calculations, single-crystal X-ray diffraction, and biomimetic transformation. Garciyunnanins C and D (1 and 2) were found to be potent Hla inhibitors in the anti-virulence efficacy evaluation against MRSA strain., (Copyright © 2021. Published by Elsevier Inc.)

Hyperformitins A-I (1-9), nine undescribed polycyclic polyprenylated acylphloroglucinols (PPAPs) with double-bond migration, along with four new isomers hyperformitins J-M (10-13), were isolated from Hypericum perforatum. Their structures and absolute configurations were determined by spectroscopic analyses including HRESIMS, IR, UV, NMR, and ECD, as well as optical rotation (OR) calculations. The absolute configurations of previously reported analogues, garsubellins D and C as well as garcinielliptones L and M, were assigned for the first time by NMR spectra and specific rotations analyses assisting with OR calculations. Selected compounds were tested for their immunosuppressive activities against lipopolysaccharide (LPS)-induced B lymphocyte proliferation. Compounds 1, 3, 4, 5, 7, and 11 showed inhibition activities against the proliferation of B lymphocyte with IC 50 values ranging from 4.1 to 9.7 μM. Furthermore, the neuroprotective activities of the isolates against corticosterone (CORT)-induced injury in PC12 cells were also tested, and compounds 1, 12, and 13 exhibited neuroprotective effects with cell viabilities of 68.0%, 71.3%, and 68.4%, respectively under the concentration of 10 μM., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Ferroptosis is a new type of cell death, which involves central neuronal system. Inhibition of ferroptosis is a promising strategy to prevent and treat neurological diseases. Thirteen phloroglucinols (1-13) were obtained from the whole plants of Hypericum japonicum. Of them, compounds 1-3 are new ones. Their structures were elucidated by extensive analysis of spectroscopic data and X-ray diffraction. All the isolates were evaluated for their inhibitory effect on RSL3-induced ferroptosis. Two new compounds 2-3 showed significant inhibitory effect with EC 50 of 0.48 ± 0.14 μM and 0.94 ± 0.14 μM, respectively. DPPH free radical scavenging abilities of all compounds were assessed to evaluate their antioxidant effect. This work first reports the anti-ferroptosis activity of phloroglucinols., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Three new polyprenylated acylphloroglucinol meroterpenoids, hyperiforins A-C (1-3), were isolated from Hypericum forrestii (Chittenden) N. Robson, together with twelve known analogues (4-15). Their structures were established by extensive physical and spectroscopic data analysis. Compounds 1, 2, 5, 7, and 13-15 showed potent inhibitory effects on protein tyrosine phosphatase 1B with IC 50 values from 6.63 ± 2.40 to 14.21 ± 3.51 μM., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Leukemia is responsible for a reason of death, globally. Even though there are several treatment regimens available in the clinics against this disease, a perfect chemotherapeutic agent for the same is still under investigation. Natural plant-derived secondary metabolites are used in clinics to treat leukemia for better benefits with reduced side-effects. Likely, several bioactive compounds from Callistemon sp. were reported for their bioactive benefits. Furthermore, acylphloroglucinol derivatives from Callistemon salignus, showed both antimicrobial and cytotoxic activities in various adherent human cancer cell lines. Thus, in the present study, a natural acylphloroglucinol (2,6-dihydroxy-4-methoxyisobutyrophenone, L72) was tested for its antiproliferative efficacy in HEL cells. The MTT and the cell cycle analysis study revealed that L72 treatment can offer antiproliferative effects, both time and dose-dependent manner, causing G 2 /M cell cycle arrest. The western blot analysis revealed that L72 treatment triggered intrinsic apoptotic machinery and activated p21. Likewise, L72 could downregulate the gene expressions of XIAP, FLT3, IDH2, and SOD2, which was demonstrated by qPCR analysis, thus promoting its antiproliferative action. The L72 could impede STAT3 expression, which was evidenced by insilico autodock analysis and western blot analysis using STAT3 inhibitor, Pimozide. The treatment of transgenic (Flk-1+/egfr+) zebrafish embryos resulted in the STAT3 gene inhibition, proving its anti-angiogenic effect, as well. Thus, the study revealed that L72 could act as an antiproliferative agent, by triggering caspase-dependent intrinsic apoptosis, reducing cell proliferation by attenuating STAT3, and activating an anti-angiogenic pathway via Flk-1inhibition., (Copyright © 2021 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Abnormalities in angiogenesis that are associated with diabetes may contribute to vascular complications and result in disabilities and death. Furthermore, an imbalance in angiogenesis in different tissues, including the retina and kidney, can play a role in the pathogenesis of diabetic microvascular complications. Phlorotannins, such as phloroglucinol (PG) and dieckol (DK), which are found in Ecklonia cava exhibit antioxidant and anti-inflammatory activities that improve endothelial function in hypertension. However, reports on the effects of these compounds on diabetes-induced angiogenesis in vivo and in vitro are scarce. In this study, we assessed the antiangiogenic effects of PG and DK on endothelial cells treated with a high concentration of glucose to mimic angiogenesis. In addition, we sought to determine the effects of these compounds on cell proliferation, cell migration, and capillary formation. In silico docking of PG and DK into VEGFR-2 revealed their potential as therapeutic agents against angiogenesis. Further, both compounds were identified to inhibit the formation of the retinal vessel in transgenic zebrafish (flk:EGFP) embryos under high glucose conditions. These findings suggested that PG and DK derived from E. cava are potential inhibitors of angiogenesis in diabetic vascular complications and could, therefore, be used to develop angiogenic agents., (Copyright © 2021 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Five new 2-nor-bicyclic polyprenylated acylphloroglucinols (BPAPs), norhyperpalums A-E (1-5), three new 2,3-nor-BPAPs, norhyperpalums F-H (8-10), one new 2,3,4-nor-BPAP (13), and four known analogs (6, 7, 11 and 12) were obtained from Hypericum patulum. Their structures were confirmed by spectroscopic data, electronic circular dichroism (ECD) calculations and comparisons, quantum-chemical 13 C NMR calculations with DP4 + probability analysis, the modified Mosher's method, Rh 2 (OCOCF 3 ) 4 -induced ECD, and X-ray crystallographic data. Norhyperpalums A-E (1-5) are rare 2-nor-BPAPs bearing a 6/5/5 system based on a hexacyclic-fused 1,6-dioxaspiro[4.4]nonane core, and norhyperpalums F and G (8 and 9) exhibit an unusual 6-oxabicyclo[3.2.1]octane architecture. More significantly, compound 2 displayed pronounced cytotoxicities against hepatoma cell lines by the induction of S-phase cell cycle arrest and promotion of cell apoptosis., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Two new type B polycyclic polyprenylated acylphloroglucinols (PPAPs) (1 and 2) and a known biogenetic precursor hyperbeanol Q (3) were isolated from the root extract of Hypericum beanii, a medicinal plant widespread in southwest China. Their chemical structures were elucidated by 1D/2D NMR and HRESIMS data analysis, and absolute configurations were determined through detailed electric circular dichroism (ECD) analysis including ECD exciton chirality, Mo 2 (OAc) 4 -induced ECD, and ECD comparison. Of these compounds, hyperbeone A (1) is a typical [3.3.1]-type B PPAP with an unusual C-1 geranyl side chain, and hyperberin C (2) possesses a rare bicyclo[5.3.1]hendecane core. Taking compound 3 as a starting point, a plausible biosynthetic pathway to the bicyclic type B frameworks of 1 and 2 was proposed., (Copyright © 2021 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.)

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 .

Hymoins A-D ( 1 - 4 ), two pairs of light-induced transformative polyprenylated acylphloroglucinols with an unprecedented pentacyclic skeleton, were isolated from the flowers of Hypericum monogynum . The first decarbonylative ring contraction of complex natural products was investigated by light irradiation. Their structures were elucidated by nuclear magnetic resonance analysis, X-ray crystallography, and electronic circular dichroism calculations. In addition, compound 3 showed moderate inhibition efficacy of the platelet-activating-factor-induced aggregation of rabbit platelets.

Astrocytes are the most abundant cell type in the central nervous system (CNS) and their major function is to maintain homeostasis of the CNS by exerting various functions. Simultaneously, reactive astrocytes are well known to be involved in the pathogenesis of neurodegenerative diseases, such as Alzheimer's disease (AD). Reactive astrocytes, induced by amyloid beta peptide (Aβ), the main component of the neuritic plaques found in AD, induce neuroinflammation, producing cytokines that lead to neuronal cell death in AD. Phloroglucinol,a polyphenol monomer and a component of phlorotannin, is found at sufficient levels in Ecklonia cava of the Laminariaceae family. Recently, several studies have reported that phloroglucinol has the ability to trap free radicals in lung fibroblasts or cancer cells. However, the effects of phloroglucinol in astrocytes have not yet been studied. Here, we found that phloroglucinol inhibits the generation of ROS induced by oligomeric Aβ 1 - 42 (oAβ 1 - 42 ) treatment in primary astrocytes. Futhermore, phloroglucinol was shown to ameliorate the protein expression of glial fibrillary acidic protein, a marker of reactive astrocytes, after treatment with oAβ 1 - 42 . These results indicate that phloroglucinol exerts antioxidant effects in primary cultured astrocytes and attenuates the astrocytic activation induced by oAβ 1 - 42 ., Competing Interests: Declaration of competing interest Not applicable., (Copyright © 2021 The Authors. Production and hosting by Elsevier B.V. All rights reserved.)

Ethnopharmacological Relevance: Hypericum perforatum L. has been widely used as a natural antidepressant. However, it is unknown whether it is effective in treating infection-induced neuropsychiatric disorders., Aim of the Study: In order to evaluate the effectiveness of H. perforatum against infection with neurotropic parasite Toxoplasma gondii, which has been linked to neuropsychiatric disorders, this study investigated the anti-Toxoplasma activity using in vitro models., Materials and Methods: Dried alcoholic extracts were prepared from three Hypericum species: H. perforatum, H. erectum, and H. ascyron. H. perforatum extract was further separated by solvent-partitioning. Hyperforin and hypericin levels in the extracts and fractions were analyzed by high resolution LC-MS. Anti-Toxoplasma activities were tested in vitro, using cell lines (Vero and Raw264), murine primary mixed glia, and primary neuron-glia. Toxoplasma proliferation and stage conversion were analyzed by qPCR. Infection-induced damages to the host cells were analyzed by Sulforhodamine B cytotoxicity assay (Vero) and immunofluorescent microscopy (neurons). Infection-induced inflammatory responses in glial cells were analysed by qPCR and immunofluorescent microscopy., Results: Hyperforin was identified only in H. perforatum among the three tested species, whereas hypericin was present in H. perforatum and H. erectum. H. perforatum extract and hyperforin-enriched fraction, as well as hyperforin, exhibited significant anti-Toxoplasma property as well as inhibitory activity against infection-induced inflammatory responses in glial cells. In addition, H. perforatum-derived hyperforin-enriched fraction restored neuro-supportive environment in mixed neuron-glia culture., Conclusions: H. perforatum and its major constituent hyperforin are promising anti-Toxoplasma agents that could potentially protect neurons and glial cells against infection-induced damages. Further study is warranted to establish in vivo efficacy., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Five non-polar phloroglucinol derivatives, viz. pseudo-aspidin, α-kosin and agripinol A-C were isolated and purified from Agrimonia pilosa Ledeb by semi-preparative counter-current chromatography. The separation was performed by a two-step elution with non-aqueous solvent systems. In the first step, an elution mode of a two-phase solvent system consisting of n-hexane-acetonitrile-dichloromethane-methanol (6:6:0.5:0.5, v/v/v/v) was used. We obtained sample Ι containing three components (47.0 mg) and sample ΙΙ containing two components (24.8 mg) from crude extract (371.0 mg). In the second step, sample Ι was successfully separated by closed-loop recycling mode with a solvent system consisting of n-hexane-acetonitrile-dichloromethane (10:7:3, v/v/v), yielding 17.8 mg of pseudo-aspidin, 18.5 mg of α-kosin and 6.4 mg of agripinol A. The other two compounds-8.7 mg of agripinol B and 13.6 mg of agripinol C-were obtained from sample ΙΙ in the same manner. All the isolated compounds had a high purity exceeding 95%., (© The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

In our screening program for new biologically active secondary metabolites, nine new polycyclic polyprenyled acylphloroglucinols, hyperscabins D-L, together with three known compounds, were obtained from the aerial parts of Hypericum scabrum. The chemical structures of 1-9 were characterized by extensive spectroscopic analyses, nuclear magnetic resonance calculation with DP4+ probability analysis, and the electronic circular dichroism spectra were calculated. Compound 1 was an unusual prenylated acylphloroglucinol decorated with a 5-oxaspiro [4,5] deca-1,9-dione skeleton. Compound 2 was a newly identified spirocyclic polyprenylated acylphloroglucinol possessing a rare 5,5-spiroketal segment. Compounds 3, 8, and 10 (10 μM) exhibited pronounced hepatoprotective activity against d-galactosamine-induced WB-F344 cell damage in vitro assays. All test compounds (1, 3, and 7-12) demonstrated potential inhibitory effects at 10 μM against noradrenalinet ([ 3 H]-NE) reuptake in rat brain synaptosome., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Hyperelodione D (1), an undescribed polyprenylated phloroglucinol derivative possessing 6/6/5/5 fused tetracyclic core, together with hyperelodiones E-F (2-3), two unreported analogues bearing 6/5/5 fused tricyclic structure, were isolated from Hypericum elodeoides Choisy. Their planar structures were elucidated by spectroscopic analysis (HRESIMS, 1D and 2D NMR) and their absolute configurations were determined by comparison of experimental and calculated ECD data. The cytotoxicity and retinoid X receptor-α (RXRα) related activities of the isolates were evaluated and the plausible biogenetic pathways of 1-3 were proposed., (Copyright © 2020 Elsevier Inc. All rights reserved.)

In this work, 26 methylated acylphloroglucinol meroterpenoids with diverse skeletons, including 18 new ones (bellumones A-R, 1 - 18 ), were identified from the flowers of Hypericum bellum . Their structures including absolute configurations were elucidated by detailed spectroscopic data, calculated electronic circular dichroism (ECD), and X-ray diffraction (XRD). Through methylation at C-5, prenylation with different chain lengths of the acylphloroglucinol-derived core, along with different types of secondary cyclization, type A bicyclic polyprenylated acylphloroglucinols (BPAPs) ( 1 - 5 and 19 - 24 ) and dearomatized isoprenylated acylphloroglucinols (DIAPs) ( 6 - 18 and 25 - 26 ) were obtained. The significant results of anti-inflammatory, antioxidant, and anti-nonalcoholic steatohepatitis (anti-NASH) activities suggest its usefulness in daily health care.

Background: Seaweeds, including marine brown algae, are traditional food sources in Asia. Phlorotannins, as the product of the polyketide pathway, are mainly found in brown algae. Different properties have been attributed to this group of marine products ranging from antiallergic to anticancer activity. Mechanism of action is not obvious for all these properties, but there are some explanations for such effects., Objective: The current study aimed to review the phlorotannins and to assess the beneficial uses in medicine., Methods: Different databases were explored with the exact terms "Phlorotannin", "Seaweed" and "Brown Algae". Data assembly was finalized by June 2019. The papers showing the effects of phlorotannins in medicine were gathered and evaluated for further assessment., Results: General physiological aspects of phlorotannins were firstly evaluated. Different arrays of pharmacological properties ranging from anti-diabetic activity to cancer treatment were found. The mechanism of action for some of these beneficiary properties has been confirmed through rigorous examinations, but there are some features with unknown mechanisms., Conclusion: Phlorotannins are characterized as a multifunctional group of natural products. Potential antioxidant characteristics could be attributed to preventive and/or their curative role in various diseases., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Our continuation on the bio-assay guided isolation from Myrtus communis Linn. led to the discovery of a new dibezofuran type phloroglucinol 1,1'-(1,3,7,9-tetrahydroxydibenzo[b,d]furan-2,8-diyl)bis(ethan-1-one) 1 . The structure was established through detailed spectroscopic studies including one and two dimensional NMR spectroscopy and electrospray ionization high resolution mass spectrometer (ESI-HRMS). The crude acetone extract from M. communis (AMA), dichloromethane fraction (DCM), and the isolated pure compound 1 were tested against pathogenic bacteria. Compound 1 displayed higher antibacterial activity against the Gram-positive and Gram-negative Staphlocococus aureus and Escherichia coli respectively as compared to the crude extract and fractions.

Acylphloroglucinol meroterpenoids are adducts of the acylphloroglucinol unit and polyprenylated fragments (terpenoids) with attractive structures and bioactivities. During study of the medicinal molecules of the genus Hypericum, the first example of dimethylated acylphloroglucinol meroterpenoids with pyran-fused 6/6/6 tricyclic skeletons ((+)/(-)-elodeoidols A-F (1-6)), along with three biogenetical homologues (7-9) were isolated from the herbaceous plant of Hypericum elodeoides. Their structures including absolute configurations were then identified by nuclear magnetic resonance (NMR), high resolution electrospray ionization mass spectroscopy (HRESIMS), electronic circular dichroism (ECD) analysis and calculations. The monoterpene moiety of 1-6 were cyclized as two cyclohexanes and fused with a dimethylated acylphloroglucinol unit through an additional ether linkage, which led to an interesting pyran-fused linear or angle type 6/6/6 tricyclic skeleton. Compounds 5, 8 and 9 showed preferable antibacterial activities against three oral bacteria, among the MIC value of (+)-5 was 6.25 μg/ml; Compounds 3, 7 and 8 exhibited significant NO inhibitory activity against LPS induced RAW264.7 cells (IC 50 : 10.39 ± 0.49 ~ 34.25 ± 2.32 μM)., (Copyright © 2020 Elsevier Inc. All rights reserved.)

In the search for new antibiotic compounds, fractionation of Pseudomonas protegens UP46 culture extracts afforded several known Pseudomonas compounds, including 2,4-diacetylphloroglucinol (DAPG), as well as two new antibacterial alkaloids, 6-(pyrrolidin-2-yl)DAPG (1) and 6-(piperidin-2-yl)DAPG (2). The structures of 1 and 2 were determined by nuclear magnetic resonance spectroscopy and mass spectrometry. Compounds 1 and 2 were found to have antibacterial activity against the Gram-positive bacteria Staphylococcus aureus and Bacillus cereus, with minimal inhibitory concentration (MIC) 2 and 4 μg ml -1 , respectively, for 1, and 2 μg ml -1 for both pathogens for 2. The MICs for 1 and 2, against all tested Gram-negative bacteria, were >32 μg ml -1 . The half maximal inhibitory concentrations against HepG2 cells for compounds 1 and 2 were 11 and 18 μg ml -1 , respectively, which suggested 1 and 2 be too toxic for further evaluation as possible new antibacterial drugs. Stable isotope labelling experiments showed the pyrrolidinyl group of 1 to originate from ornithine and the piperidinyl group of 2 to originate from lysine. The P. protegens acetyl transferase (PpATase) is involved in the biosynthesis of monoacetylphloroglucinol and DAPG. No optical rotation was detected for 1 or 2, and a possible reason for this was investigated by studying if the PpATase may catalyse a stereo-non-specific introduction of the pyrrolidinyl/piperidinyl group in 1 and 2, but unless the PpATase can be subjected to major conformational changes, the enzyme cannot be involved in this reaction. The PpATase is, however, likely to catalyse the formation of 2,4,6-triacetylphloroglucinol from DAPG.

Hookerianones A - E (1-5), five new polyprenylated acylphloroglucinols (PPAPs), along with six known ones, were isolated from the aerial parts of Hypericum hookerianum. Their structures were elucidated by analyses of MS, NMR, chiroptical properties, biogenetic pathway, and/or single crystal X-ray diffraction. A ubiquitin-rhodamine 110 assay showed that furohyperforin and hypercalin C, two representative PPAPs in this plant, inhibited more than 90% USP7 at the concentration of 10 μM., Competing Interests: Declaration of Competing Interest The authors declare no competing financial interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Eleven new acylphloroglucinols, including six new formylated phloroglucinol-monoterpene meroterpenoids, eucalyprobusals A-F (1-6), one monomeric acylphloroglucinol, eucalyprobusone B (7), and four dimeric acylphloroglucinols, eucalyprobusones C-F (8-11) were purified from the fruits of Eucalyptus robusta. The establishment of the structures of 1-11 was achieved by a combination of NMR and HRESIMS data analyses, electron circular dichroism (ECD), and single-crystal X-ray diffraction. Compounds 6, 8, and an inseparable mixture of 10 and 11 were found to be potent AChE inhibitors with IC 50 values of 3.22 ± 0.36, 3.82 ± 0.22, and 2.55 ± 0.28 μΜ, respectively. Possible interaction sites of 6, 8, 10, and 11 with AChE were investigated by means of molecular docking studies, and the results revealed that AChE residues Asn87, Ser125, Thr83, Tyr133, Tyr124, Tyr337, and Tyr341 played crucial roles in the observed activity of the aforementioned compounds., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Rhotomentodiones C-E, three new polymethylated phloroglucinol meroterpenoids with diverse configurations, were isolated from the twigs and leaves of Rhodomyrtus tomentosa. Their structures and absolute configurations were established mainly by means of comprehensive spectroscopic data and electron circular dichroism (ECD) calculation. Among them, Rhotomentodione D (2) exhibited both antibacterial activity with an MIC value of 12.5 μg/mL against Propionibacterium acnes and AChE inhibitory activity with an IC 50 value of 22.9 μm., (© 2020 Wiley-VHCA AG, Zurich, Switzerland.)

Six new terpenoids (1-6) and two new phloroglucinol glucosides (7 and 8) were isolated from the extract of Syzygium szemaoense leaves. Among the isolates, compounds 1 and 2 (named syzygiumursanolides A and B) were unusual 28-norursane type triterpenoids with 19(18→17)-abeo spirocyclic skeleton. And syzygiumone B (8) was rare ascorbyl-modified phloroglucinol glucoside. Their structures were elucidated on the basis of comprehensive 1D and 2D NMR, HRESIMS spectroscopic data analysis, as well as experimental and calculated ECD spectra and acid hydrolysis. Antimicrobial bioassay revealed that syzygiumursanolide D (4) displayed the most potent antifungal activities with MIC values ranging from 6.25 to 25 μg/mL against a panel of fungi., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Three undescribed polycyclic polyprenylated acylphloroglucinols (PPAPs) and three tocotrienols derivatives, named as paucinochymol A-F (1-3 and 10-12), together with six known PPAPs, were isolated from the fruits of Garcinia paucinervis. Their structures and absolute configurations were determined by extensive NMR analysis and electronic circular dichroism (ECD) calculation methods. Paucinochymol A (1) is the first compound of this type featuring a ω-isogeranyl with tetrahydrofuran unit at C-1. Paucinochymols D and E (4-5) belong to rare tocotrienol with one glorious macrocyclic and an ortho-quinone moiety, respectively. The antiproliferative and anti-inflammatory activities of all isolates were tested. Four PPAPs exhibited weak inhibitory activities against three human cancer cell lines (HepG2, T98, MCF-7) with IC 50 values ranging from 10.0 to 16.0 μM. Paucinochymol D (10) displayed moderate inhibitory effects against nitric oxide (NO) production with the IC 50 value of 19.8 μM., Competing Interests: Declaration of Competing Interest There are no conflicts to declare., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Glioblastoma is the most common primary brain tumor with poor survival rate and without effective treatment strategy. Notably, amplification and active mutation of epidermal growth factor receptor (EGFR) occur frequently in glioblastoma patient that may be a potential treatment target. Several studies indicated that various type of herbal compounds not only regulate anti-depressant effect but also shown capacity to suppress glioblastoma growth via inducing apoptosis and inhibiting oncogene signaling transduction. Hyperforin, an herb compound derived from St. John's wort was used to treat depressive disorder by inhibiting neuronal reuptake of several neurotransmitters. Although hyperforin can reduce matrix metallopeptidases-2 (MMPs) and -9-mediated metastasis of glioblastoma, the detail mechanism of hyperforin on glioblastoma is remaining unclear. Here, we suggested that hyperforin may induce extrinsic/intrinsic apoptosis and suppress anti-apoptotic related proteins expression of glioblastoma. We also indicated that hyperforin-mediated anti-apoptotic potential of glioblastoma was correlated to inactivation of EGFR/extracellular signal-regulated kinases (ERK)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling., (© 2020 Wiley Periodicals LLC.)

Three new compounds, 4-geranyloxy-2-hydroxy-6-isoprenyloxybenzophenone ( 1 ), hypericumone A ( 2 ) and hypericumone B ( 3 ), were obtained from the aerial parts of Hypericum sampsonii , along with six known compounds ( 4 - 9 ). The structures of these compounds were determined through spectroscopic and MS analyses. Hypericumone A ( 2 ), sampsonione J ( 8 ) and otogirinin A ( 9 ) exhibited potent inhibition (IC 50 values ≤ 40.32 μM) against lipopolysaccharide (LPS)-induced nitric oxide (NO) generation. Otogirinin A ( 9 ) possessed the highest inhibitory effect on NO production with IC 50 value of 32.87 ± 1.60 μM. The well-known proinflammatory cytokine , tumor necrosis factor-alpha (TNF-α) was also inhibited by otogirinin A ( 9 ). Western blot results demonstrated that otogirinin A ( 9 ) downregulated the high expression of inducible nitric oxide synthase (iNOS). Further investigations on the mechanism showed that otogirinin A ( 9 ) blocked the phosphorylation of MAPK/JNK and IκBα, whereas it showed no effect on the phosphorylation of MAPKs/ERK and p38. In addition, otogirinin A ( 9 ) stimulated anti-inflammatory M2 phenotype by elevating the expression of arginase 1 and Krüppel-like factor 4 (KLF4). The above results suggested that otogirinin A ( 9 ) could be considered as potential compound for further development of NO production-targeted anti-inflammatory agent.

Modulation of major histocompatibility complex (MHC) expression using drugs has been proposed to control immunity. Phytochemical investigations on Garcinia species have allowed the isolation of bioactive compounds such as polycyclic polyprenylated acylphloroglucinols (PPAPs). PPAPs such as guttiferone J ( 1 ), display anti-inflammatory and immunoregulatory activities while garcinol ( 4 ) is a histone acetyltransferases (HAT) p300 inhibitor. This study reports on the isolation, identification and biological characterization of two other PPAPs, i.e., xanthochymol ( 2 ) and guttiferone F ( 3 ) from Garcinia bancana , sharing structural analogy with guttiferone J ( 1 ) and garcinol ( 4 ). We show that PPAPs 1 - 4 efficiently downregulated the expression of several MHC molecules (HLA-class I, -class II, MICA/B and HLA-E) at the surface of human primary endothelial cells upon inflammation. Mechanistically, PPAPs 1 - 4 reduce MHC proteins by decreasing the expression and phosphorylation of the transcription factor STAT1 involved in MHC upregulation mediated by IFN-γ. Loss of STAT1 activity results from inhibition of HAT CBP/p300 activity reflected by a hypoacetylation state. The binding interactions to p300 were confirmed through molecular docking. Loss of STAT1 impairs the expression of CIITA and GATA2 but also TAP1 and Tapasin required for peptide loading and transport of MHC. Overall, we identified new PPAPs issued from Garcinia bancana with potential immunoregulatory properties.

A new polycyclic polyprenylated acylphloroglucinol ( 1 ), nujiangefolin D, together with five known analogues ( 2-6 ), were isolated from the fruits of Garcinia nujiangensis . Compound 1 was screened by the LC-MS and LC-PDA. The structure of 1 was elucidated on the basis of extensive spectroscopic techniques including 1 D and 2 D NMR and MS analyses. The compounds isolated were evaluated for their cytotoxic activities against three cancer cell lines, 1 showed moderate cytotoxic activity against Hela, PANC-1, and MDA-MB-231 cell lines with IC 50 values of 5.6 ± 0.1, 9.1 ± 0.2, and 8.3 ± 0.2  μ M, respectively. The antitumor mechanism was explained via virtual docking of 1 to the main sites in the human serine/threonine-protein kinase mTOR (mTOR) crystal structure (PDB code: 4DRI). Furthermore, 1 may inhibit Hela cell proliferation through mTOR by the western blotting analysis. Taken together, 1 may be a potential mTOR inhibitor used for the treatment of cervical cancer.

Eight new polyprenylated benzoylphloroglucinol derivatives ( 1 - 8 ) and four known analogues ( 9 - 12 ) were isolated from the stem bark of Garcinia picrorhiza . Their structures were determined by spectroscopic data analysis (1D and 2D NMR and HRESIMS), and the absolute configurations were established by single-crystal X-ray diffraction combined with experimental and calculated ECD data. The new metabolites represent rare examples of benzoylphloroglucinols bearing a cyclobutyl-containing side chain. The isolated compounds were evaluated for their cytotoxic properties against five types of human cancer cells (KB, HeLa S3, MCF-7, Hep G2, and HT-29 cells) and their inhibitory activities against COX-1 and COX-2 enzymes. The cytotoxicity results showed that compound 6 was active against KB, HeLa S3, MCF-7, and Hep G2 cancer cells, with IC 50 values ranging from 5.9 to 9.4 μM. Among the compounds tested for cyclooxygenase inhibition, compound 8 possessed the highest inhibitory effect toward COX-1 (35.2 ± 9.6% inhibition at 20 μM).