Potent Inhibitor Research Articles

Pharmacodynamic effects and exploratory efficacy of afimetoran, a TLR7/8 inhibitor, in patients with cutaneous lupus erythematosus

Background: Cutaneous lupus erythematosus (CLE) is a chronic inflammatory skin condition occurring alone or as a manifestation of systemic lupus erythematosus (SLE). There is an unmet need for safe and effective CLE-focused treatments. Afimetoran is an investigational, first-in-class, potent oral inhibitor of toll-like receptors (TLRs) 7/8. Given the involvement of TLRs 7/8 in SLE, afimetoran may have therapeutic potential for CLE. A phase 1b randomized, double-blind, placebo-controlled study (NCT04493541) demonstrated preliminary safety and efficacy of afimetoran in patients with active CLE. We assessed the pharmacodynamics, safety, and efficacy of afimetoran and its impact on CLE pathobiology. Methods: Patients aged 18–65 years with SLE and cutaneous manifestations by EULAR/ACR 2019 classification criteria or biopsy-proven CLE, and modified CLE Disease Area and Severity Index-Activity (CLASI-A) score ≥6, were randomized 2:1 to once-daily afimetoran (30 mg) or placebo for 16 weeks with a 4-week post-treatment follow-up period. The primary endpoints were safety and tolerability; efficacy was exploratory. Transcriptomics and cytokine analyses were performed using peripheral whole blood and serum, respectively, at baseline (pre-dose) and each study visit (weeks 1, 2, 4, 8, 12, 16, and 20 [post-dose]). Statistical analyses compared data from the 13 randomized patients with thirteen age-, ethnicity-, and gender-matched healthy volunteers. Treatment responses were evaluated longitudinally in each treatment arm. The dataset was analyzed using a linear regression model. Gene set variation analysis (GSVA) was performed for pathway enrichment. Results: 13 patients with CLE were randomized (afimetoran, n=8; placebo, n=5); 12 patients completed 16 weeks of treatment and 1 discontinued after 6 weeks due to COVID-19. Compared with placebo, afimetoran demonstrated a favorable safety profile with no serious adverse events, and showed a greater reduction in CLASI-A scores as early as week 4, which persisted to week 20. Improvement in the molecular disease profile was rapid (week 1), sustained through the 16-week treatment period, and the 4-week post-treatment follow-up period. Expression of interferon (IFN) pathway genes was significantly reduced with afimetoran compared with baseline (ΔGSVA enrichment score [ES]=1.57, P<0.0001) and placebo (ΔGSVA ES=0.56, P<0.01); this effect was maintained through week 16 and ≥4 weeks post-treatment. Expression of TLR7 and TLR8 pathway genes and key cytokines (interleukin [IL]-6, tumor necrosis factor α, IL-18, IFNγ, macrophage inflammatory protein-1 alpha [CCL3/MiP1α] or beta [CCL4/MiP1β]) were greatly reduced with afimetoran treatment. GSVA demonstrated robust pharmacodynamic activity on immune cell populations, including immature and activated dendritic cells, macrophages, and inflammatory pathway signatures. Conclusion: In patients with CLE, afimetoran was safe, well tolerated, and demonstrated durable efficacy beyond the treatment period. Afimetoran’s clinical effects and potent pharmacodynamic impact on the molecular disease profile suggest a substantial therapeutic benefit for patients with CLE.

Thrombospondin 1 Mediates Autophagy Upon Inhibition of the Rho-Associated Protein Kinase Inhibitor

Age-related macular degeneration (AMD) is a degenerative eye disease leading to central vision loss and is characterized by dysregulated autophagy of the retinal pigment epithelium (RPE) layer. Recent studies have suggested that rho-associated protein kinase (ROCK) inhibitors may enhance autophagy in neurodegenerative diseases and promote the survival of RPE cells. This study investigated the effect of ROCK inhibitors on autophagy gene expression and autophagic vacuole formation in a human RPE (ARPE-19) cell line. The highly selective and potent ROCK inhibitor Y-39983 enhanced the expression of autophagy genes in ARPE-19 cells and increased autophagic vacuole formation. A proteomic analysis using mass spectrometry was performed to further characterize the effects of ROCK inhibition at the protein level. Y-39983 downregulated thrombospondin-1 (THBS1), and suppression of THBS1 in ARPE-19 cells resulted in an increase in autophagic vacuole formation. Our data showed that ROCK inhibitor-induced autophagy was mediated by THBS1 downregulation. We identified ROCK and THBS1 as potential novel therapeutic targets in AMD.

Chemical Constituents of the Deep-sea Derived Fungus Purpureocillium lilacinum XIA-9.

Two new sphingosine derivatives (1 and 2), two new vicinal diol analogs (3 and 4), one new diol analog (5), one new fatty acid (9), together with 19 known compounds (6-8, 10-24), were isolated from Purpureocillium lilacinum XIA-9. Their structures were determined by detailed analysis of the 1D and 2D NMR, HRESIMS, and optical rotatory data. Fusarubin 3-methyl ether (17) exhibited potent inhibition on RSL3 induced ferroptosis with the EC50 value of 0.1 μM.

Discovery of novel and highly potent dual-targeting PKMYT1/HDAC2 inhibitors for hepatocellular carcinoma through structure-based virtual screening and biological evaluation

Simultaneous inhibition of two or more pathways is playing a crucial role in the treatment of hepatocellular carcinoma with complex and diverse pathogenesis. However, there have been no reports of dual-targeting inhibitors for protein kinase membrane-associated tyrosine/threonine 1 (PKMYT1) and histone deacetylase 2 (HDAC2), which are critical targets for hepatocellular carcinoma treatment. Here, an integrated strategy of virtual screening was utilized to identify dual-targeting inhibitors for PKMYT1 and HDAC2. Notably, PKHD-5 has been identified as a potent inhibitor that selectively targets both PKMYT1 and HDAC2 with nanomolar affinity. Molecular dynamics have confirmed the strong binding stability of PKHD-5 with PKMYT1 and HDAC2. Importantly, it displayed a notably lower IC50 against the HepG2/MDR cell line, underscoring its potential to surmount drug resistance, while exhibiting minimal toxicity towards the normal liver cell line L02. Additionally, PKHD-5 has demonstrated significant antitumor proliferation effects without significant toxicity. In summary, the results suggest that PKHD-5 is a promising candidate for further preclinical studies of hepatocellular carcinoma therapy.

COMPUTATIONAL SCREENING OF POTENT ANTI-INFLAMMATORY COMPOUNDS FOR HUMAN MITOGEN-ACTIVATED PROTEIN KINASE: A COMPREHENSIVE AND COMBINED IN SILICO APPROACH

Objective: Inflammatory diseases have a serious impact on one’s life and represent a diverse group of ailments stemming from various causes and presenting in various forms. p38α of the mitogen-activated protein kinase family plays a crucial role in regulating inflammation, where the activation of this kinase initiates a cascade of events resulting in the production of proinflammatory mediators and cellular stress responses. In this context, attempts were made to identify potent small-molecule inhibitors of p38α and assess their binding affinity through molecular docking studies. Methods: From comprehensive reviews of several published reports, a few compounds, such as P38, P39, VPC00628, and N17, have shown substantial inhibitory activity toward p38α at various concentrations. Hence, these four compounds were chosen as lead compounds, and small-molecule libraries were constructed on the basis of their structural similarity. Next, virtual screening docking was performed to investigate the inhibitory potency of the four libraries toward the p38α isoforms (DFG-out and DFG-in), providing insights into their potential mechanisms of action. Results: In addition, a comprehensive analysis of physicochemical and pharmacokinetic properties was also performed for the identified hits from each library. Our findings have shown that, compared with those of the p38α DFG-in motif, the binding energies of the p38α DFG-out motif are greater. Conclusion: Furthermore, a few compounds from each library presented binding energies higher than those of their respective lead compounds, confirming their potential as novel therapeutic agents against inflammation.

Identification of novel PAD2 inhibitors using pharmacophore-based virtual screening, molecular docking, and MD simulation studies.

In the realm of epigenetic regulation, Protein arginine deiminase 2 (PAD2) stands out as a therapeutic target due to its significant role in neurological disorders, rheumatoid arthritis (RA), multiple sclerosis (MS), and various cancers. To date, no in silico studies have focused on PAD2 for lead compound identification. Therefore, we conducted structure-based pharmacophore modeling, virtual screening, molecular docking, molecular dynamics (MD) simulations, and essential dynamics studies using PCA and free energy landscape analyses to identify repurposed drugs and selective inhibitors against PAD2. The best pharmacophore model, 'Pharm_01,' had a selectivity score of 10.485 and an excellent ROC curve quality of 0.972. Pharm1 consisted of three hydrogen bond donors (HBD) and two hydrophobic (Hy) features (DDDHH). A virtual screening of about 9.2million compounds yielded 2575 hits using a fit value threshold of 2.5 and drug-likeness criteria. Molecular docking identified the top ten molecules, which were verified using MD simulations. Stability was verified using MM-PBSA studies, whereas conformational differences were investigated using PCA and free energy landscape analyses. Two hits (Leads 1 and 2) from the DrugBank dataset showed promise for repurposing as PAD2 inhibitors, while one hit compound (Lead 8) from the ZINC database emerged as a novel PAD2 inhibitor. These findings indicate that the discovered compounds may be potent PAD2 inhibitors, necessitating additional preclinical and clinical research to produce viable treatments for cancer and neurological disorders.

Identification of Potential Inhibitors of Histone Deacetylase 6 Through Virtual Screening and Molecular Dynamics Simulation Approach: Implications in Neurodegenerative Diseases

Background: Histone deacetylase 6 (HDAC6) plays a crucial role in neurological, inflammatory, and other diseases; thus, it has emerged as an important target for therapeutic intervention. To date, there are no FDA-approved HDAC6-targeting drugs, and most pipeline candidates suffer from poor target engagement, inadequate brain penetration, and low tolerability. There are a few HDAC6 clinical candidates for the treatment of mostly non-CNS cancers as their pharmacokinetic liabilities exclude them from targeting HDAC6-implicated neurological diseases, urging development to address these challenges. They also demonstrate off-target toxicity due to limited selectivity, leading to adverse effects in patients. Selective inhibitors have thus been the focus of development over the past decade, though no selective and potent HDAC6 inhibitor has yet been approved. Methods: This study involved an integrated virtual screening against HDAC6 using the DrugBank database to identify repurposed drugs capable of inhibiting HDAC6 activity. The primary assessment involved the determination of the ability of molecules to bind with HDAC6. Subsequently, interaction analyses and 500 ns molecular dynamics (MD) simulations followed by essential dynamics were carried out to study the conformational flexibility and stability of HDAC6 in the presence of the screened molecules, i.e., penfluridol and pimozide. Results: The virtual screening results pinpointed penfluridol and pimozide as potential repurposed drugs against HDAC6 based on their binding efficiency and appropriate drug profiles. The docking results indicate that penfluridol and pimozide share the same binding site as the reference inhibitor with HDAC6. The MD simulation results showed that stable protein–ligand complexes of penfluridol and pimozide with HDAC6 were formed. Additionally, MMPBSA analysis revealed favorable binding free energies for all HDAC6–ligand complexes, confirming the stability of their interactions. Conclusions: The study implies that both penfluridol and pimozide have strong and favorable binding with HDAC6, which supports the idea of repositioning these drugs for the management of neurodegenerative disorders. However, further in-depth studies are needed to explore their efficacy and safety in biological systems.

Benzofuran-chalcone derivatives as VEGFR-2 inhibitors: synthesis and anticancer evaluation.

The discovery and development of efficient VEGFR-2 inhibitors has become a research hotspot in cancer treatment. In this work, a series of new benzofuran-based chalcone derivatives have been prepared, and in vitro anticancer activities have been evaluated. The results revealed that derivatives showed selective cytotoxic activity against HCC1806, Hela and A549 cell lines, especially 5c exhibited excellent inhibitory effect on VEFGR-2 (IC50 = 1.07 nM). The molecular docking study indicated that 5c had an obvious binding site with the target VEGFR-2 (PDB ID: 4BSK). Therefore, the benzofuran-based chalcone derivatives could be potent VEGFR-2 inhibitors.

UPLC-ESI/MSn metabolic profiling of Cedrela odorata L. and Toona ciliata M. Roem and in vitro investigation of their anti-diabetic activity supported with molecular docking studies

IntroductionThe genus Cedrela is one of the phytochemically rich genera of the family Meliaceae. In this study, two Cedrela species, namely, Cedrela odorata and Toona ciliata M. Roem (formerly Cedrela toona), were selected for in-depth phytochemical profiling with the aid of UPLC-ESI/MSn analysis followed by evaluation of their anti-diabetic potential through assessment of in vitro α-amylase and α-glucosidase inhibitory effects, alongside the molecular docking studies on these target enzymes.Materials and methodsUPLC-ESI/MSn technique was applied to tentatively identify the extracts. The anti-diabetic properties were assessed using BioVision α-amylase and α-glucosidase inhibitor screening kits. Further, the molecular docking studies utilized PyRx® and Discovery Studio software.Results and discussionThe UPLC-ESI/MSn analysis led to the identification and quantification of 55 metabolites with their fragmentation patterns for the first time for these two species. Flavonoids represented the main identified class, followed by phenylpropanoids, terpenes, tannins, and others. The two species showed potent enzyme inhibition, where C. odorata and C. toona significantly inhibited α-amylase (IC50 = 4.83 ± 0.01 and 3.50 ± 0.03 μg/mL) compared to pioglitazone (IC50 = 2.17 ± 0.23 μg/mL), while their α-glycosidase inhibitory properties were also potent with (IC50 = 7.17 ± 0.01 and 6.50 ± 0.69 μg/mL), respectively, compared to acarbose (IC50 = 4.83 ± 1.02 μg/mL). The enzyme inhibitory activities were further confirmed by in silico molecular docking of the main identified components with the respective binding sockets in both α-amylase and α-glycosidase enzymes.ConclusionThese promising results could pave the way for a novel discovery of natural phytoconstituents with potent anti-diabetic activity.

Discovery of highly potent and ALK2/ALK1 selective kinase inhibitors using DNA-encoded chemistry technology

Activin receptor type 1 (ACVR1; ALK2) and activin receptor like type 1 (ACVRL1; ALK1) are transforming growth factor beta family receptors that integrate extracellular signals of bone morphogenic proteins (BMPs) and activins into Mothers Against Decapentaplegic homolog 1/5 (SMAD1/SMAD5) signaling complexes. Several activating mutations in ALK2 are implicated in fibrodysplasia ossificans progressiva (FOP), diffuse intrinsic pontine gliomas, and ependymomas. The ALK2 R206H mutation is also present in a subset of endometrial tumors, melanomas, non-small lung cancers, and colorectal cancers, and ALK2 expression is elevated in pancreatic cancer. Using DNA-encoded chemistry technology, we screened 3.94 billion unique compounds from our diverse DNA-encoded chemical libraries (DECLs) against the kinase domain of ALK2. Off-DNA synthesis of DECL hits and biochemical validation revealed nanomolar potent ALK2 inhibitors. Further structure-activity relationship studies yielded center for drug discovery (CDD)-2789, a potent [NanoBRET (NB) cell IC50: 0.54 μM] and metabolically stable analog with good pharmacological profile. Crystal structures of ALK2 bound with CDD-2281, CDD-2282, or CDD-2789 show that these inhibitors bind the active site through Van der Waals interactions and solvent-mediated hydrogen bonds. CDD-2789 exhibits high selectivity toward ALK2/ALK1 in KINOMEscan analysis and NB K192 assay. In cell-based studies, ALK2 inhibitors effectively attenuated activin A and BMP-induced Phosphorylated SMAD1/5 activation in fibroblasts from individuals with FOP in a dose-dependent manner. Thus, CDD-2789 is a valuable tool compound for further investigation of the biological functions of ALK2 and ALK1 and the therapeutic potential of specific inhibition of ALK2.

Screening Inhibitors of α-Amylase in Polygala Radix Based on an Online Targeted Detection System and Molecular Docking.

Targeted screening of inhibitors of key enzymes in the progression of diabetes from natural products is one of the effective methods for the treatment of diabetes. Polygala has been proved to reduce glucose levels; however, the bioactive compounds in Polygalae Radix (PR) that have anti-diabetic properties are unknown. The purpose of this study was to explore the material basis of the anti-diabetic effect of PR by inhibiting α-amylase through an online detection system and molecular docking. An online analysis platform was established and optimized for the screening of potent enzyme inhibitors from complex mixtures based on ultra-performance liquid chromatography-photodiode array-quadrupole-time-of-flight-mass spectrometry-α-amylase-fluorescence detector (UHPLC-PDA-Q-TOF-MSn-α-amylase-FLD) detection system and molecular docking, which could efficiently separate extracts, quickly detect α-amylase inhibitors, and determine their structures. Molecular docking confirms the inhibition of these compounds. The molecular interaction between α-amylase and the active compound was evaluated. Among the 101 compounds identified, 28 compounds had a strong inhibitory effect on α-amylase. Molecular docking screening confirmed the inhibition of these compounds and evaluated the molecular interactions between α-amylase and 30 active compounds, which strongly supported the experimental results. Among the evaluated compounds, onjisaponin R (83) and polygalaxanthone III (11) have the strongest inhibitory activity to α-amylase (the binding energies were -9.639 and -8.972 kcal/mol, respectively) and are potential lead compounds against diabetes. This study proved the feasibility of using the existing platform to screen the active ingredients in PR extract, and provided a practical method for the rapid screening of potential anti-diabetic active ingredients in traditional Chinese medicine.

Discovery and Preclinical Characterization of Fulacimstat (BAY 1142524), a Potent and Selective Chymase Inhibitor As a New Profibrinolytic Approach for Safe Thrombus Resolution.

Chymase is a serine-protease produced by mast cells. In the past few decades, its role in fibrotic diseases triggered the search for orally available chymase inhibitors. Aiming at reducing adverse cardiac remodeling after myocardial infarction, our research efforts resulted in the discovery of fulacimstat (BAY 1142524). While clinical trials did not demonstrate efficacy in this indication, the recent discovery of a new unexpected biological role of chymase spurred a revival of interest in chymase inhibition: chymase was shown to inactivate plasmin within fibrin-rich clots. Chymase inhibitors are now considered as potential profibrinolytic drugs with low bleeding risk and therefore exceptional safety for the treatment of acute thrombosis settings such as stroke, pulmonary embolism, or venous thrombosis. This article describes the chemical optimization journey from a screening hit to the discovery of fulacimstat (BAY 1142524), a selective chymase inhibitor with a good safety profile, as well as its preclinical in vitro and in vivo characterization.

Design and Evaluation of Peptide Inhibitors Targeting the Dimerization of SARS-CoV-2 Main Protease.

The severe acute respiratory syndrome virus 2 (SARS-CoV-2) seriously impacted public health. The evolutionarily conserved viral chymotrypsin-like main protease (Mpro) is an important target for anti-SARS-CoV-2 drug development. Previous studies have shown that the eight N-terminal amino acids (N8) of SARS-CoV Mpro are essential for its dimerization, and are used to design inhibitors against SARS-CoV Mpro dimerization. Here, we established a simple readout assay using SDS-PAGE and Coomassie blue staining to measure inhibitory activity of N8 peptide derived from SARS-CoV-2 Mpro. To optimize its inhibitory effect, we then modified the side-chain length, charge, and hydrophilicity of the N8 peptide, and introduced a mutated Mpro recognition sequence. As a result, we obtained a series of potent peptide inhibitors against SARS-CoV-2 Mpro, with N8-A24 being the most efficient with an IC50 value of 1.44 mM. We observed that N8-A24 reduced Mpro dimerization with an IC50 value of 0.86 mM. Molecular docking revealed that N8-A24 formed hydrogen bond interactions with critical dimeric interface residues, thus inhibiting its dimerization and activity. In conclusion, our study not only discovers a series of peptide inhibitors targeting the SARS-CoV-2 Mpro dimerization, but also provides a promising strategy for the rational design of new inhibitors against COVID-19.

Design, synthesis and biological studies of new isoxazole compounds as potent Hsp90 inhibitors.

Heat shock protein 90 (Hsp90), a molecular chaperone, contributes to the preservation of folding, structure, stability, and function proteins. In this study, novel compounds comprising isoxazole structure were designed, synthesized and their potential ability as Hsp90 inhibitors was validated through docking studies. The active site-based compounds were prepared through a multi-step synthesis process and their chemical structures were characterized employing FT-IR, NMR, and mass spectrometry analysis. Cytotoxic and Hsp90 inhibition activities of synthesized compounds were assessed by MTT assay and ELISA kit, respectively. Based on the obtained results, compound 5 exhibited the highest cytotoxicity (IC50; 14 µM) against cancer cells and reduced Hsp90 expression from 5.54 ng/mL in untreated (normal cells) to 1.56 ng/mL in cancer cells. Moreover, molecular dynamics (MD) simulation results indicated its high affinity to target protein and approved its excellent stability which is essential for exerting an inhibitory effect on cancer cell proliferation.

Abstract I003: Inhibitors of DHX9 RNA helicase as synthetic lethal cancer therapeutics

Abstract Over 100 modifications to RNA are known to occur in human cells, where they play critical roles in many aspects of normal cellular physiology, such as cell fate decisions and terminal differentiation, through effects on RNA biology such as protein and nucleic acid interactions. Our survey of human RNA-modifying enzymes suggests many are cancer essential enzymes with striking synthetic lethal profiles, including the DHX9 helicase. DHX9 is a multifunctional DExH-box RNA helicase which can unwind regions of double-stranded DNA and RNA helices but has a greater propensity for secondary structures such as DNA/RNA hybrids (R-loops) and DNA/RNA G-quadruplexes. DHX9 interacts with and regulates many proteins, including key members of DNA damage repair pathways. We have found that DHX9 knockdown is synthetic lethal in microsatellite high (MSI-H) or defective mismatch repair (dMMR) tumor models. A suite of assays was developed to identify and optimize potent and selective inhibitors of the DHX9 helicase, which recapitulate our findings with genetic tools. Profiling of DHX9 inhibitors across a broad panel of cancer cell lines reveals that tumor cells with mutations in the DNA damage repair genes BRCA1 and/or BRCA2 are also responsive to DHX9 inhibitor treatment in vitro and in vivo. DHX9 inhibition leads to increased RNA/DNA secondary structures such as R-loops and G-quadruplexes, resulting in subsequent DNA damage and increased replication stress, leading to cell cycle arrest and apoptosis. These results suggest that DHX9 inhibitors are a novel treatment modality for patients with defective DNA damage repair pathways such as dMMR and/or BRCA mutations. Citation Format: Serena J Silver. Inhibitors of DHX9 RNA helicase as synthetic lethal cancer therapeutics [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr I003.

A novel phosphodiesterase 5 inhibitor, RF26, improves memory impairment and ameliorates tau aggregation and neuroinflammation in the P301S tauopathy mouse model of Alzheimer's disease.

Phosphodiesterase-5 (PDE5) inhibitors are primarily used in the treatment of erectile dysfunction and pulmonary hypertension, but have also been reported to have a potential therapeutic effect for the treatment of Alzheimer's disease (AD). This is likely to be through stimulation of nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling by elevating cGMP, a secondary messenger involved in processes of neuroplasticity. In the present study, we evaluated the efficacy of a novel PDE5 inhibitor, RF26, using P301S tauopathy mice model. A body of experimental evidence suggests that the development of tau inclusions leads to the neurodegeneration observed in tauopathies, including AD, Frontotemporal dementia (FTD), Supranuclear palsy and others. RF26 successfully targeted NO/cGMP signaling pathway and showed a significant improvement of spatial memory task performance of P301S mice using Morris Water Maze and T-maze. Furthermore, RF26 -treated mice showed a significant reduction of phosphorylated tau load, gliosis and downregulated pro-inflammatory cytokines. The presented data support the efficacy of RF26 as a potent PDE5 inhibitor and calls for further investigation as a potential therapeutic drug for Alzheimer's and other tauopathy related neurological disorders.

Crystal structure of β-d-galactofuranosidase from Streptomyces sp. JHA19 in complex with an inhibitor provides insights into substrate specificity.

d-Galactofuranose (Galf) is widely distributed in glycoconjugates of pathogenic microbes. β-d-Galactofuranosidase (Galf-ase) from Streptomyces sp. JHA19 (ORF1110) belongs to glycoside hydrolase (GH) family 2 and is the first identified Galf-specific degradation enzyme. Here, the crystal structure of ORF1110 in complex with a mechanism-based potent inhibitor, d-iminogalactitol (Ki = 65 μm) was solved. ORF1110 binds to the C5-C6 hydroxy groups of d-iminogalactitol with an extensive and integral hydrogen bond network, a key interaction that discriminates the substrates. The active site structure of ORF1110 is largely different from those of β-glucuronidases and β-galactosidases in the same GH2 family. A C-terminal domain of ORF1110 is predicted to be a carbohydrate-binding module family 42 that may bind Galf. The structural insights into Galf-ase will contribute to the investigation of therapeutic tools against pathogens.

Development and Biological Evaluation of New Diphenyl Ether Formylhydrazide Compounds as Potent Inhibitors of Succinate Dehydrogenase.

Succinate dehydrogenase (SDH), also recognized as succinate ubiquinone oxidoreductase (SQR), is considered one of the most promising targets for fungicide development, garnering significant international interest. We have focused on the development of highly effective, broad-spectrum-targeted SDH inhibitors. Using an active scaffold combining strategy, we designed and synthesized a series of novel diphenyl ether formylhydrazine derivatives, and most compounds have demonstrated broad-spectrum antifungal activity. Notably, compound M8 exhibited antifungal activity of more than 93% against four tested pathogen types at a concentration of 10 μg/mL, with an EC50 value below 0.3 μg/mL for each pathogen, outperforming boscalid. Additionally, compound M8 exhibited a control efficacy of 83% against Sclerotinia sclerotiorum on rapeseed leaves at a concentration of 200 μg/mL and demonstrated an 87% efficacy in controlling Fusarium graminearum on wheat ears when applied at 400 μg/mL. Structure-activity relationship research suggested that para-substituted benzene rings are more effective, offering stronger and more extensive antifungal potency. Further investigation, including enzyme inhibition assays, mycelial morphology observations, and molecular docking studies, suggests that the antifungal potency of M8 is due to the inhibition of its SDH activity. Therefore, our research positions compound M8 as a highly promising lead compound with broad-spectrum antifungal properties, potentially introducing a new class of fungicide.

Masterpenoids A-D, Four Unprecedented Nortriterpenoids from the Mastic (Pistacia lentiscus) and Their Anti-inflammatory Activity.

Four unprecedented nortriterpenoids, masterpenoids A-D, were isolated and fully elucidated from the resin of the mastic tree (Pistacia lentiscus). Masterpenoids A-C are the first norterpenoids featuring an unprecedented 6/6/6/10 ring system, while masterpenoid D possesses a novel 6/6/6/7/5 ring system. The anti-inflammatory potential of the compounds was meticulously assessed through the establishment of an in vitro model of lipopolysaccharide-induced inflammation in RAW264.7 macrophage cells. Among them, Masterpenoids A and D showed potent inhibition of NO production, with IC50 values of 10.6 ± 0.8 and 8.2 ± 0.9 μM, respectively, compared to positive control dexamethasone (IC50 = 23.2 ± 1.2 μM).

Dual Assay Validation of Rosmarinus officinalis Extract as an Inhibitor of SARS-CoV-2 Spike Protein: Combining Pseudovirus Testing, Yeast Two-Hybrid, and UPLC-Q Exactive Orbitrap-MS Profiling.

This study evaluates the effectiveness of Traditional Chinese Medicine (TCM) extracts in blocking the interaction between the SARS-CoV-2 Spike protein and human ACE2 receptor, utilizing a dual-method approach to explore the antiviral potential of natural compounds. This work aims to evaluate the capability of TCM extracts in inhibiting the SARS-CoV-2 Spike protein and ACE2 receptor interaction using advanced biochemical assays. A dual-method screening approach was utilized, beginning with a pseudovirus assay to assess the inhibition capabilities of TCM extracts invitro, followed by a split-ubiquitin yeast two-hybrid (Y2H) system to validate interactions in live cells. Active compounds were characterized and quantified using UPLC-Q-Exactive-Orbitrap-MS. Among the 91 TCM extracts tested, Rosmarinus officinalis exhibited the most potent inhibition in both pseudovirus and Y2H assays, significantly reducing viral entry and disrupting the Spike-ACE2 interaction. Comprehensive chemical profiling via UPLC-Q-Exactive-Orbitrap-MS identified 132 compounds, including phenolics, flavonoids, and terpenoids. This research validates the use of TCM extracts in viral inhibition strategies, demonstrating the utility of integrating traditional remedies with modern scientific approaches to discover new therapeutic agents.