Semisynthesis of 22,25-Epoxylanostane Triterpenoids: Structure Revision and Protective Effects against Oxygen-Glucose Deprivation/Reoxygenation Injury in H9c2 Cells.

22,25-Epoxylanostane triterpenoids indicated protective effects against oxygen-glucose deprivation/reoxygenation (OGD/R)-induced myocardial injury in a previous study. In order to discover potent cardioprotective agents, 20 22,25-epoxylanostane triterpenoids, including inonotsuoxides A and B, ganodercochlearins A and B, were synthesized from inotodiol (1). The structures of inonotsuoxide B and ganodercochlearin A are revised as 22R,25-epoxylanosta-8-en-3ß,24R-diol (6) and 22S,25-epoxylanosta-7,9(11)-dien-3ß,24R-diol (12) respectively, based on synthesis, spectroscopic data analysis, and X-ray crystallography. Compounds 13-16 and 22 showed potential protective activity against OGD/R-induced injury in H9c2 cells at a concentration of 20 µM. After OGD/R treatment, the most active compounds 13 and 22 at 5 µM increased cell viability by 11.4% and 6.4% respectively, whereas the positive control diazoxide was 14.9% at 100 µM. Flow cytometric analysis and JC-1 staining assay revealed that 13 suppressed OGD/R-induced apoptosis and the mitochondrial membrane potential in H9c2 cells. Compound 13 may serve as a potential lead cardioprotective agent for further development.

Steroidal Saponins from the Rhizomes of Smilax china and Their Inhibitory Effects on Lipopolysaccharide-Induced Proinflammatory Cytokines Expression.

Four new furostanol saponins (1:  - 4: ) and a new pregane-type saponin (5: ) along with six known steroidal saponins (6:  - 11: ) were isolated from the rhizomes of Smilax china. The structures of 1:  - 5: were elucidated by extensive analysis of NMR and HR-ESI-MS data in addition to enzymatic hydrolysis and other chemical methods. Compounds 1, 4: , and 11: showed inhibitory activity against the expression of proinflammatory mediators, inducible nitric oxide synthase, interleukin-1ß, interleukin-6, and tumor necrosis factor-α in lipopolysaccharide-induced RAW264.7 cells. Compound 1: , at a concentration of 20 µM, decreased the production of inducible nitric oxide synthase, interleukin-1ß, interleukin-6, and tumor necrosis factor-α by 36, 62, 72, and 67%, respectively, which is comparable to that of the positive control dexamethasone.

Axial Chiral Binaphthoquinone and Perylenequinones from the Stromata of Hypocrella bambusae Are SARS-CoV-2 Entry Inhibitors.

A new axial chiral binaphtoquinone, hypocrellone (1), and a new perylenequinone, hypomycin F (2), were isolated from the stromata of Hypocrella bambusae, together with five known compounds, 3-7. The structures of 1 and 2 were assigned by spectroscopic and HRESIMS data analyses. The axial chirality of 1 was determined by electronic circular dichroism data analysis, and the absolute configurations of 2 and 3 were determined by X-ray crystallography. The axial chirality of 7 was determined by UV-induced photooxidation from 4. Compounds 1, 4, and 5 showed inhibitory activity against pseudotyped SARS-CoV-2 infection in 293T-ACE2 cells with IC50 values of 0.17, 0.038, and 0.12 µM. Compounds 4 and 5 were also active against live SARS-CoV-2 infection with EC50 values of 0.22 and 0.21 µM, respectively. Further cell-cell fusion assays, surface plasmon resonance assays, and molecular docking studies revealed that 4 and 5 could bind with the receptor-binding domain of SARS-CoV-2 S protein to prevent its interaction with human angiotensin-converting enzyme II receptor. Our results revealed that 4 and 5 are potential SARS-CoV-2 entry inhibitors.

Achyrodimer F, a tyrosyl-DNA phosphodiesterase I inhibitor from an Australian fungus of the family Cortinariaceae.

Mass-guided isolation of the dichloromethane/methanol extracts from a specimen of teleomorphic fungus of the family Cortinariaceae resulted in the identification of a new dimeric cyclobutane metabolite, achyrodimer F (1), along with the monomers hispidin (2) and bisnoryangonin (3). Their structures were determined by NMR and MS data analyses. Density Function Theory (DFT) NMR calculations was employed to confirm the chemical structure of achyrodimer F. Compound 1 inhibited tyrosyl-DNA phosphodiesterase I with an IC50 value of 1µM.

Phenolic Compounds from the Rhizomes of Smilax china L. and Their Anti-Inflammatory Activity.

A new triflavanoid, kandelin B-5 (1), was isolated from the rhizomes of Smilax china L., together with six known phenylpropanoid substituted flavan-3-ols (2-7), nine flavonoids (8-16), two stilbenoids (17, 18), and two other compounds (19, 20). The structure of compound 1 was determined on the basis of 1D, 2D NMR and HR-ESI-MS data, as well as chemical method. Compounds 2-5, 8-12, 15, 17, and 19 were evaluated for anti-inflammatory activity. Only compounds 10, 15 and 17 showed slightly IL-1ß expression inhibitory activities on LPS induced THP-1 cells, with inhibition rate of 15.8%, 37.3%, and 35.8%, respectively, at concentration of 50 µg/mL.

Tyrosyl-DNA Phosphodiesterase I Inhibitors from the Australian Plant Macropteranthes leichhardtii.

Mass-directed isolation of the CH2Cl2/MeOH extract from the bark of an Australian plant, Macropteranthes leichhardtii, resulted in the purification of a new phenylpropanoid glucoside, macropteranthol (1), together with four known analogues (2-5). The structure of compound 1 was elucidated by NMR and MS data analyses and quantum chemical calculations. Compounds 3 and 5 showed inhibitory activity against tyrosyl-DNA phosphodiesterase I with IC50 values of ∼1.0 µM.

ApoE secretion modulating bromotyrosine derivative from the Australian marine sponge Callyspongia sp.

High throughput screening of a pre-fractionated natural product library identified 11 active fractions showing ApoE modulation activity. Mass-directed fractionation of one active crude extract from the Australian marine sponge Callyspongia sp. resulted in the isolation of 13 metabolites, including three new bromotyrosine derivatives, callyspongic acid (1), 3,5-dibromo-4-methoxyphenylpyruvic acid (2), N-acetyl-3-bromo-4-hydroxylphenylethamine (3), and ten known compounds (4-13). The structure elucidation of compounds 1-3 was based on their 1D and 2D NMR and MS spectroscopic data. 3,5-Dibromo-4-methoxyphenylpyruvic acid (2) showed weak activity in increasing the apolipoprotein E secretion from human CCF-STTG1 cells at the concentration of 40 µM.

Aplysinellamides A-C, bromotyrosine-derived metabolites from an Australian Aplysinella sp. marine sponge.

Mass-directed fractionation of an extract from the Australian marine sponge Aplysinella sp., from the Great Barrier Reef, resulted in the isolation of four new bromotyrosine derivatives, aplysinellamides A-C (1-3) and aplysamine-1-N-oxide (4), along with six known compounds (5-10). The structure elucidation of compounds 1-4 was based on their 1D and 2D NMR and MS spectroscopic data. Aplysamine-1 (6) increased the apolipoprotein E secretion from human CCF-STTG1 astrocytoma cells by 2-fold at the concentration of 30 µM.

Arjunolic acid ameliorates lipopolysaccharide-induced depressive behavior by inhibiting neuroinflammation via microglial SIRT1/AMPK/Notch1 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Neuroinflammation is involved in the pathogenesis of depression disorder by activating microglia cells, increasing proinflammatory cytokines, effecting serotonin synthesis and metabolism, and neuronal apoptosis and neurogenesis. Arjunolic acid (ARG) is a triterpenoid derived from the fruits of Akebia trifoliata for treating psychiatric disorders in TCM clinic, which exhibits anti-inflammatory and neuroprotective effects. However, its anti-depressive effect and underlying mechanism are unknown. AIM OF THE STUDY: The aim of this study is to explore the effect of arjunolic acid on depression and its possible mechanisms. METHODS: Intraperitoneal injection of LPS in mice and LPS stimulated-BV2 microglia were utilized to set up in vivo and in vitro models. Behavioral tests, H&E staining and ELISA were employed to evaluate the effect of arjunolic acid on depression. RT-qPCR, immunofluorescence, molecular docking and Western blot were performed to elucidate the molecular mechanisms. RESULTS: Arjunolic acid dramatically ameliorated depressive behavior in LPS-induced mice. The levels of BDNF and 5-HT in the hippocampus of the mice were increased, while the number of iNOS + IBA1+ cells in the brain were decreased and Arg1+IBA1+ positive cells were increased after arjunolic acid treatment. In addition, arjunolic acid promoted the polarization of BV2 microglia from M1 to M2 type. Notably, drug affinity responsive target stability (DARTS), cellular thermal shift assay (CETSA) and molecular docking technologies identified SIRT1 as the target of arjunolic acid. Moreover, after SIRT1 inhibition by using EX-527, the effects of arjunolic acid on ameliorating LPS-induced depressive behavior in mice and promoting M2 Microglia polarization were blocked. In addition, arjunolic acid activated AMPK and decreased Notch1 expression, however, inhibition of AMPK, the effect of arjunolic acid on the downregulation of Notch1 expression were weaken. CONCLUSIONS: This study elucidates that arjunolic acid suppressed neuroinflammation through modulating the SIRT1/AMPK/Notch1 signaling pathway. Our study demonstrates that arjunolic acid might serve as a potiential anti-depressant.

Daldiconoids A-G: 3,4-Secolanostane triterpenoids from the fruiting bodies of Daldinia concentrica and their anti-inflammatory activity.

Seven undescribed 3,4-secolanostane triterpenoids, daldiconoids A-G (1-7), were isolated from the fruiting bodies of Daldinia concentrica. Daldiconoid A (1) was a highly modified 4,6,28,29-tetranorlanostane triterpenoid alkaloid featuring an unusual δ-lactam fused with a flanking cyclopentenone architecture. Their structures were determined by spectroscopic data, NMR calculations coupled with the DP4+ analysis, X-ray single-crystal diffraction, and chemical transformation. The plausible biosynthetic pathway for 1 was proposed. Compounds 1, 2, and 4-6 inhibited the expressions of IL-1ß, IL-6, and TNF-α in lipopolysaccharide stimulated RAW264.7 cells at a concentration of 10 µM. Mechanistically, Compounds 1 and 2 blocked the JAK2/STAT3 signaling pathway induced by lipopolysaccharide.

Phelligridimer A enhances the expression of mitofusin 2 and protects against cerebral ischemia/reperfusion injury.

Mitochondrial dysfunction and endoplasmic reticulum (ER) stress play pivotal roles in the pathology of cerebral ischemia. In this study, we investigated whether phelligridimer A (PA), an active compound isolated from the medicinal and edible fungus Phellinus igniarius, ameliorates ischemic cerebral injury by restoring mitochondrial function and restricting ER stress. An in vitro cellular model of ischemic stroke-induced neuronal damage was established by exposing HT-22 neuronal cells to oxygen-glucose deprivation/reoxygenation (OGD/R). An in vivo animal model was established in rats subjected to middle cerebral artery occlusion/reperfusion (MCAO/R). The results showed that PA (1-10 µM) dose-dependently increased HT-22 cell viability, reduced OGD/R-induced lactate dehydrogenase release, and reversed OGD/R-induced apoptosis. PA reduced OGD/R-induced accumulation of reactive oxygen species, restored mitochondrial membrane potential, and increased ATP levels. Additionally, PA reduced the expression of the 78-kDa glucose-regulated protein (GRP78) and the phosphorylation of inositol-requiring enzyme-1α (p-IRE1α) and eukaryotic translation-initiation factor 2α (p-eIF2α). PA also inhibited the activation of the mitogen-activated protein kinase (MAPK) pathway in the OGD/R model. Moreover, treatment with PA restored the expression of mitofusin 2 (Mfn-2), a protein linking mitochondria and ER. The silencing of Mfn-2 abolished the protective effects of PA. The results from the animal study showed that PA (3-10 mg/kg) significantly reduced the volume of cerebral infarction and neurological deficits, which were accompanied by an increased level of Mfn-2, and decreased activation of the ER stress in the penumbra of the ipsilateral side after MCAO/R in rats. Taken together, these results indicate that PA counteracts cerebral ischemia-induced injury by restoring mitochondrial function and reducing ER stress. Therefore, PA might be a novel protective agent to prevent ischemia stroke-induced neuronal injury.

AßPP-tau-HAS1 axis trigger HAS1-related nuclear speckles and gene transcription in Alzheimer's disease.

As the backbone of the extracellular matrix (ECM) and the perineuronal nets (PNNs), hyaluronic acid (HA) provides binding sites for proteoglycans and other ECM components. Although the pivotal of HA has been recognized in Alzheimer's disease (AD), few studies have addressed the relationship between AD pathology and HA synthases (HASs). Here, HASs in different regions of AD brains were screened in transcriptomic database and validated in AßPP/PS1 mice. We found that HAS1 was distributed along the axon and nucleus. Its transcripts were reduced in AD patients and AßPP/PS1 mice. Phosphorylated tau (p-tau) mediates AßPP-induced cytosolic-nuclear translocation of HAS1, and negatively regulated the stability, monoubiquitination, and oligomerization of HAS1, thus reduced the synthesis and release of HA. Furthermore, non-ubiquitinated HAS1 mutant lost its enzyme activity, and translocated from the cytosol into the nucleus, forming nuclear speckles (NS). Unlike the splicing-related NS, less than 1 % of the non-ubiquitinated HAS1 co-localized with SRRM2, proving the regulatory role of HAS1 in gene transcription, indirectly. Thus, differentially expressed genes (DEGs) related to both non-ubiquitinated HAS1 mutant and AD were screened using transcriptomic datasets. Thirty-nine DEGs were identified, with 64.1 % (25/39) showing consistent results in both datasets. Together, we unearthed an important function of the AßPP-p-tau-HAS1 axis in microenvironment remodeling and gene transcription during AD progression, involving the ubiquitin-proteasome, lysosome, and NS systems.

Bisbenzylisoquinoline alkaloids from Plumula Nelumbinis inhibit vascular smooth muscle cells migration and proliferation by regulating the ORAI2/Akt pathway.

Plumula Nelumbinis, the embryo of the seed of Nelumbo nucifera Gaertn, is commonly used to make tea and nutritional supplements in East Asian countries. A bioassay-guided isolation of Plumula Nelumbinis afforded six previously undescribed bisbenzylisoquinoline alkaloids, as well as seven known alkaloids. Their structures were elucidated by extensive analysis of HRESIMS, NMR, and CD data. Pycnarrhine, neferine-2α,2'ß-N,N-dioxides, neferine, linsinine, isolinsinine, and nelumboferine, at 2 µM significantly suppressed the migration of MOVAS cells with inhibition ratio above 50%, more active than that of the positive control cinnamaldehyde (inhibition ratio 26.9 ± 4.92%). Additionally, neferine, linsinine, isolinsinine, and nelumboferine, were also active against the proliferation of MOVAS cells with inhibition ratio greater than 45%. The preliminary structure-activity relationships were discussed. Mechanism studies revealed that nelumboferine inhibited the migration and proliferation of MOVAS cells by regulating ORAI2/Akt signaling pathway.

Phenolic compounds from the branches of Eucalyptus maideni.

Three new phenolic compounds, eucalmaidin F (1), (3S)-5-guaiacyl-3-hydroxypentanoic acid (2), and 8-ß-C-glucopyranosyl-5,7-dihydroxy-2-isobutylchromone (3), were isolated from the branches of E. maideni, together with 30 known compounds, including four phenylpropanoids, three lignans, four phloroglucinol glucosides, five dihydroflavonoids, seven simple phenolic compounds, six terpenoids, and glycerol. The new structures were established by spectroscopic studies (MS, and 1D- and 2D-NMR), chemical degradation, and modified Mosher's method. Compounds 3, guaiacylglycerol, 3-hydroxy-1-(4-hydroxyphenyl)propan-1-one, caffeic acid, (2E)-3-(4-hydroxyphenyl)prop-2-enoic acid, (7'S,8R,8'R)-lyoniresinol, (+)-lyoresinol 3α-O-α-L-rhamnopyranoside, garcimangosone, phlorocetophenone 2'-glucopyranoside, (+)-taxifolin 3α-O-α-L-rhamnopyranoside, (+)-aromadendrin, (+)-taxifolin, resveratrol, piceatannol, 3,4,5-trihydroxyphenol. Tachiaside, gallic acid, macrocapals A und G, and oleuropeic acid were evaluated for their cytotoxicities against five human cancer cell lines. Resveratrol, piceatannol, gallic acid, and macrocapal G exhibited moderate inhibitory effects on human myeloid heukemia HL-60 cell, with IC(50) values of 22.05, 22.05, 7.75, and 31.93 µM, respectively; and only macrocapal G showed inhibitory effect on hepatocellular carcinoma SMMC-7721 cell, with an IC(50) value of 26.75 µM.

Cardioprotective 22-hydroxylanostane triterpenoids from the fruiting bodies of Phellinus igniarius.

Seven undescribed 22-hydroxylanostane triterpenoids were isolated from the fruiting bodies of Phellinus igniarius, together with three known sterols. Their structures were assigned by extensive spectroscopic and HRESIMS data analyses. The absolute configurations of C-22 were determined by X-ray crystallography, chemical methods, and spectroscopic data comparison. Phellinol G was a 25,26,27-trinorlanostane triterpenoid glycoside. 22S/22R-25,26,27- Trinorlanosta-8-en-3ß,22,24-triols with the same side chain as that of phellinol G were stereoselectively synthesized from commercial lanosterol for the first time. The key step involved Sharpless asymmetrical epoxidation. Phellinols A, B, and F showed cardioprotective activity against oxygen-glucose deprivation/reoxygenation injury in H9c2 cells at a concentration of 20 µM.

Phloroglucinol glycosides from the fresh fruits of Eucalyptus maideni.

Five new phloroglucinol glycosides, eucalmainosides A-E (1-5), were isolated from the fresh fruits of Eucalyptus maideni, along with 15 flavonoids (6-20), seven (+)-oleuropeic acid derivatives (15, 16, and 22-26), three hydrolyzable tannins (32-34), and six simple phenolic compounds (21, 27-31). Their structures were determined on the basis of spectroscopic analyses, including HSQC, HMBC, and acidic hydrolysis. The in vitro anti-herpes simplex virus 1 (HSV-1) assay indicated that the flavonols, myricetin (6) and quercetin (7), and the ellagitannin isocoriariin F (33) showed weak anti-HSV-1 activity with TIC values of 0.31, 0.33, and 0.12 mM, respectively.

A new polyhydroxylated oleanane triterpenoid from the roots of Rhodomyrtus tomentosa.

A new oleanane triterpenoid, 2α,3ß,6ß,23,29-pentahydroxyolean-12-en-28- oic acid (1), was isolated from the roots of Rhodomyrtus tomentosa, together with four known oleanane triterpenoids (2-5) and two known ursane triterpenoids (6-7). The structure of compound 1 was determined by extensive NMR and HR-ESI-MS data analysis. Compounds 4-5 showed cytotoxicity against PC12 cell lines at a concentration of 50 µM, and compound 1 exhibited moderate neuroprotective activity against corticosterone induced PC12 cell death at the same concentration.

7-O-methylkaempferol and -quercetin glycosides from the whole plant of Nervilia fordii.

Five new 7-O-methylkaempferol and -quercetin glycosides, namely, nervilifordins A-E (1-5), were isolated from the whole plant of Nervilia fordii, together with seven known flavonoids (6, 7, and 9-13) and one known coumarin (8). Their structures were elucidated on the basis of extensive spectroscopic analyses, including HSQC, HMBC, ROESY, and chemical methods. Compounds 1-3 and 6-13 were evaluated for their anti-herpes simplex virus 1 (HSV-1) activity and cytotoxicity on African green monkey kidney cells (Vero cells) in vitro. Of the tested compounds, only esculetin (8) exhibited antiviral activity against HSV-1, while the aglycones (11-13) showed stronger cytotoxicity on Vero cells than their glycosides (1-3, 6, and 7).

Eucalmaidins A-E, (+)-oleuropeic acid derivatives from the fresh leaves of Eucalyptus maideni.

Five new (+)-oleuropeic acid derivatives, eucalmaidins A-E (1-5), together with 12 known compounds (6-17), were isolated from the fresh leaves of Eucalyptus maideni. Structures of the new compounds were determined on the basis of spectroscopic analyses (HSQC, HMBC, and (1)H-(1)H COSY), chemical degradation, and enzymatic hydrolysis. Of the tested compounds, only quercetin showed slight anti-herpes simplex virus 1 (HSV-1) activity in vitro.

Phomopsols A and B from the Mangrove Endophytic Fungus Phomopsis sp. xy21: Structures, Neuroprotective Effects, and Biogenetic Relationships.

A polyketide-derived alkaloid featuring a unique 3,4-dihydro-2H-indeno[1,2-b]pyridine 1-oxide motif, named phomopsol A (1), and a highly oxidized polyketide containing a new 3,5-dihydro-2H-2,5-methanobenzo[e][1,4]dioxepine moiety, named phomopsol B (2), were isolated from the Thai mangrove endophytic fungus Phomopsis sp. xy21, together with the related biosynthetic polyketide 3. The structures of 1-3 were unambiguously established by single-crystal X-ray diffraction analysis (Cu Kα), and their neuroprotective effects in PC12 cells were evaluated. The biosynthetic origins of 1-3 are proposed.