Lead Compounds Research Articles

Effect of a phthalate derivative purified from Bacillus zhangzhouensis SK4 on quorum sensing regulated virulence factors of Pseudomonas aeruginosa

Pseudomonas aeruginosa causes life-threatening diseases and is resistant to almost all conventional antibiotics. The quorum sensing (QS) system of P. aeruginosa contributes to many pathogenic factors some of which are pigment production, motility, and biofilm. The disruption of quorum sensing system may be an impactful strategy to deal with infections. The present study investigates the anti-quorum sensing property of a bioactive molecule extracted from marine epibiotic bacteria present on the surface of seaweeds. Among all the isolates tested against monitor strain Chromobacterium violaceum (MTCC 2656), the one with the highest activity was identified as Bacillus zhangzhouensis SK4. The culture supernatant was extracted with chloroform which was then partially purified by TLC and column chromatography. The probable anti-QS compound was identified as 1,2-benzenedicarboxylic acid, bis (2-methylpropyl ester) by GC-MS and NMR analysis. The treatment of P. aeruginosa MCC 3457 with the lead compound resulted in the reduced production of pyocyanin, rhamnolipids, exopolysaccharide, biofilm, and motility. The observations of light and scanning electron microscopy also supported the biofilm inhibition. The lead compound showed synergism with the meropenem antibiotic and significantly reduced MIC. The molecular docking and pharmacokinetics study predicted 1, 2-benzenedicarboxylic acid, bis (2-methylpropyl ester), a phthalate derivative as a good drug candidate. The molecular dynamics study was also performed to check the stability of the lead compound and LasR complex. Further, lead compounds did not exhibit any cytotoxicity when tested on human embryonic kidney cells. As per our knowledge, this is the first report on the anti-QS activity of B. zhangzhouensis SK4, indicating that epibiotic bacteria can be a possible source of novel compounds to deal with the multidrug resistance phenomenon.

Cholinesterase Inhibitory and In Silico Toxicity Assessment of Thirty-Four Isoquinoline Alkaloids - Berberine as the Lead Compound

Cholinesterase (ChE) inhibitors used currently in clinics for the treatment of Alzheimer's disease (AD) are the most prescribed drug class with nitrogen-containing chemical formula. Galanthamine, the latest generation anti-ChE drug, contains an isoquinoline structure. The aim of the current study was to investigate the inhibitory potential of thirty-four isoquinoline alkaloids, e.g. (-)-adlumidine, β-allocryptopine, berberine, (+)-bicuculline, (-)-bicuculline, (+)-bulbocapnine, (-)-canadine, (±)-chelidimerine, corydaldine, (±)-corydalidzine, (-)-corydalmine, (+)-cularicine, dehydrocavidine, (+)-fumariline, (-)-fumarophycine, (+)-α-hydrastine, (+)-isoboldine, 13-methylcolumbamine, (-)-norjuziphine, norsanguinarine, (-)-ophiocarpine, (-)-ophiocarpine-N-oxide, oxocularine, oxosarcocapnine, palmatine, (+)-parfumine, protopine, (+)-reticuline, sanguinarine, (+)-scoulerine, (±)-sibiricine, (±)-sibiricine acetate, (-)-sinactine, and (-)-stylopine isolated from several Fumaria (fumitory) and Corydalis species towards acetyl- (AChE) and butyrylcholinesterase (BChE) by microtiter plate assays. The alkaloids with strong ChE inhibition were proceeded to molecular docking simulations as well as in silico toxicity screening for their mutagenic capacity through VEGA QSAR (AMES test) consensus model and VEGA platform as statistical approaches. The inputs were evaluated in a simplified molecular input-line entry system (SMILES). ChE inhibition assays indicated that the highest AChE inhibition was caused by berberine (IC50: 0.72 ± 0.04 µg/mL), palmatine (IC50: 6.29 ± 0.61 µg/mL), β-allocryptopine (IC50: 10.62 ± 0.45 µg/mL), (-)-sinactine (IC50: 11.94 ± 0.44 µg/mL), and dehydrocavidine (IC50: 15.01 ± 1.87 µg/mL) as compared to that of galanthamine (IC50: 0.74 ± 0.01 µg/mL), the reference drug with isoquinoline skeleton. Less number of the tested alkaloids exhibited notable BChE inhibition. Among them, berberine (IC50: 7.67 ± 0.36 µg/mL) and (-)-corydalmine (IC50: 7.78 ± 0.38 µg/mL) displayed a stronger inhibition than that of galanthamine (IC50: 12.02 ± 0.25 µg/mL). The mutagenic activity was shown for β-allocryptopine, (+)- and (-)-bicuculline, (±)-corydalidzine, (-)-corydalmine, (+)-cularicine, (-)-fumarophycine, (-)-norjuziphine, (-)-ophiocarpine-N-oxide, (+)-scoulerine, (-)-sinactine, and (-)-stylopine by means of in silico experiments. The results obtained by molecular docking simulations of berberine, palmatine, and (-)-corydalmine suggested that the estimated free ligand-binding energies of these compounds inside the binding domains of their targets are reasonable to make them capable of establishing strong polar and nonpolar bonds with the atoms of the active site amino acids. Our findings revealed that berberine, palmatin, and (-)-corydalmine stand out as the most promising isoquinoline alkaloids in terms of ChE inhibition. Among them, berberine has displayed a robust dual inhibition against both ChEs and could be evaluated further as a lead compound for AD.

Screening and Activity Evaluation of Novel BCR-ABL/T315I Tyrosine Kinase Inhibitors.

Chronic myeloid leukemia (CML) is a kind of malignant tumor formed by the clonal proliferation of bone marrow hematopoietic stem cells. BCR-ABL fusion protein, found in more than 90% of patients, is a vital target for discovering anti-CML drugs. Up to date, imatinib is the first BCR-ABL tyrosine kinase inhibitor (TKI) approved by the FDA for treating CML. However, the drug resistance problems appeared for many reasons, especially the T135I mutation, a "gatekeeper" of BCR-ABL. Currently, there is no long-term effective and low side effect drug in clinical. This study intends to find novel TKIs targeting BCR-ABL with high inhibitory activity against T315I mutant protein by combining artificial intelligence technology and cell growth curve, cytotoxicity, flow cytometry and western blot experiments. The obtained compound was found to kill leukemia cells, which had good inhibitory efficacy in BaF3/T315I cells. Compound No 4 could induce cell cycle arrest, cause autophagy and apoptosis, and inhibit the phosphorylation of BCR-ABL tyrosine kinase, STAT5 and Crkl proteins. The results indicated that the screened compound could be used as a lead compound for further research to discover ideal chronic myeloid leukemia therapeutic drugs.

Computational Study of Lactucine and its Derivatives to Investigate its Anti-cancerous Properties Targeting Apoptosis-inducing Protein

Background: Lactucine is related to the sesquiterpene lactone group of naturally occurring compounds and has a variety of pharmacological effects including anticancer properties found in Chicory, Wormwood, Laurus nobilis, Pyrethrum, Chamomile, etc. Lactucine has an anticancer effect which may induce apoptosis in cancerous cells and protect other cells from getting infected. Objective: In this study, Lactucine and its derivatives were screened, and performed their in silico docking study with the proteins involved in the apoptosis-inducing effect in human leukemia cancer. Methods: The three-dimensional structure of lactucine and its derivatives were retrieved in the SDF format. Active sites of protein structures were determined by Sitemap. LigPrep module was used for geometrical refining of chemical structures of lactucine and its derivatives. The protein preparation wizard of Maestro (Schrodinger) was used for protein preparation. From the receptor-complex structure, the cocrystallized ligands were removed from the active site position of the receptor chain. All ligands were docked using default Glide settings for a grid centered on the ligand and structure. Flexible docking was performed using the extra precision (XP) feature of Glide module. The best docking poses for the lactucine and their derivatives were selected based on their docking score. The ADMET properties of lactucine 15- oxalate have been predicted by admetSAR software. Results: Proteins and ligands three-dimensional structures were retrieved from PDB and Pubchem databases, respectively. All lactucine derivatives suitably docked on the apoptosis-inducing proteins with ample Glide scores Lactucin 15-oxalate interacts with proteins which are responsible for apoptosis with a maximum of six H-bonds. Other types of interactions are also involved, like Pi-cation, Pi-Pi stacking, salt bridges, and halogen bonds. Protein CDK-4 has shown the highest number of H-bond (LYS142 salt bridges), ALA16, VAL14, ASP99, LYS35, TYR17, and ASN145) with the Lactucin 15-oxalate. ADMET properties of lactucin 15-oxalate met with the criteria of being eligible to be a novel drug for the treatment of human leukemia cancer. The Dock score of both the Dasatinib drug and the lactucine-15-oxalate with the apoptosis-inducing protein stipulates that the selected ligand has equitable interaction with the target proteins. Conclusion: In this study, lactucine derivatives were docked with apoptosis-inducing proteins for the prediction of its anticancer effect. Lactucin15-oxalate has shown the highest binding affinity for the CDK-4 target and can be used as a lead compound for cancer treatment. Glide and Dock score for docking of lactucin 15-oxalate with CDK-4, well as the number of hydrogen bonding, is in agreement to use this ligand for study. These in silico results are valuable to proceed with the in vitro and in vivo studies related to the anti-cancer role of lactucin 15-oxalate.

Exploration and Validation of Lead Molecules against Yellow Fever through High Throughput Virtual Screening and Molecular Dynamics Simulation

Background: Yellow fever (YF) is a mosquito-borne flaviviral hemorrhagic fever (VHF) that causes severe hepatitis, renal failure, bleeding, and quick terminal events such as shock and multi-organ failure. There are currently no particular anti-viral medications for the management of the YF virus (YFV). Despite the availability of a commercial YFV vaccination, there are roughly 30,000 fatalities globally each year, with instances rising over the previous 20 years. After being translocated into the endoplasmic reticulum lumen, glycosylated NS1 resides as a membrane-associated dimer, where it is required for viral genome replication. The secreted hexamer NS1 has a role in immune evasion and pathogenesis and has been discovered as a possible diagnostic marker for the early identification of viral infections. Objective: The main aim of this study is to analyze the small molecule as a potent drug candidate against the target NS1 protein. Methods: In this study, Computational approaches, including high throughput virtual screening, molecular docking, and dynamics simulation, were carried out against the target NS1 protein using three different chemical libraries Enamine, Asinex, and NCI. The selected lead compounds were validated through HOMO-LUMO analysis, ADME prediction, and Toxicity parameters to analyze the biological and pharmacological properties of the lead small molecules. Results: From the result, it was concluded that the leads possessed the highest docking scores, interacting with the binding residues, and were stable in the simulation period. Conclusion: Overall findings revealed that the lead three small molecules could act as the potential drug candidate for the target NS1 protein to inhibit the diseasing efficacy of Yellow fever.

Discovery of novel EGFR-PROTACs capable of degradation of multiple EGFR-mutated proteins

Although three generations of Epidermal growth factor receptor (EGFR) - TK inhibitors have been approved for the treatment of Non-small-cell lung cancers (NSCLC), their clinical application is still largely hindered by acquired drug resistance mediated new EGFR mutations and side effects. The Proteolysis targeting chimera (PROTAC) technology has the potential to overcome acquired resistance from mutant EGFR through a novel mechanism of action. In this study, we developed the candidate degrader IV-3 by structural modifications of the lead compound 13, which exhibited limited antiproliferative activity against HCC-827 cells. Compared to compound 13, IV-3 exhibited remarkable anti-proliferative activity against HCC-827 cells, NCI–H1975 cells, and NCI–H1975-TM cells (IC50 = 0.009 μM, 0.49 μM and 3.24 μM, respectively), as well as significantly inducing degradation of EGFR protein in these cell lines (DC50 = 17.93 nM, 0.25 μM and 0.63 μM, respectively). Further investigations confirmed that IV-3 exhibited superior anti-tumor activity in all xenograft tumor models through the degradation of mutant EGFR protein. Moreover, IV-3 showed no inhibitory activity against A431 and A549 cells expressing wild-type EGFR, thereby eliminating potential toxic side effects emerging from wild-type EGFR inhibition. Overall, our study provides promising insights into EGFR-PROTACs as a potential therapeutic strategy against EGFR-acquired mutation.

A Computational Investigation on Chitosan Derivatives using Pharmacophore- based Screening, Molecular Docking, and Molecular Dynamics Simulations against Kaposi Sarcoma.

Cancer is one of the most dangerous illnesses to the human body due to its severity and progressive nature. Kaposi's Sarcoma (KS) tumor can appear as painless purple spots on the legs, foot, or face. This cancer develops in the lining of lymph arteries and blood vessels. Along with the enlargement of lymph nodes, the vaginal region and the mouth portion are the additional target areas of KS. DNA-binding proteins known as Sox proteins are found in all mammals and belong to the HMG box superfamily. They controlled a wide range of developmental procedures, such as the formation of the germ layer, the growth of organs, and the selection of the cell type. Human developmental abnormalities and congenital illnesses are frequently caused by the deletion or mutation of the Sox protein. The purpose of this study is to determine the promising Kaposi's sarcoma inhibitors through computational studies. In this present study computational approaches were used to evaluate the anti- carcinogenic efficacy against Kaposi's sarcoma. Ligand-based pharmacophore screening was performed utilising four different chemical libraries (Asinex, Chembridge, Specs, and NCI Natural products (NSC)) depending on the top hypothesis. The top hits were examined using molecular docking, absorption, distribution, metabolism and excretion. Highest occupied molecular orbital and lowest unoccupied molecular orbital were analysed to determine the lead compounds' biological and pharmacological efficacy. The results of the study indicated that the leading candidates were possible SOX protein inhibitors. A pharmacophore model to inhibit the production of SOX protein in Kaposi Sarcoma was generated in this computational experiment using a set of 19 Chitosan compounds. The results revealed that the top hits responded to all of the pharmacological druglikening criteria and had the best interaction residues, fitness scores, and docking scores. The resulting leads might be potential Kaposi's Sarcoma alternative treatments.

2D QSAR Modelling, Docking, Synthesis and Evaluation of 2-substituted Benzimidazole Derivatives as Anti-breast Cancer Agents

Background: Cancer is a leading cause of death worldwide and is anticipated to reach 28,4 million fresh cases globally by 2040. Despite all the progress made in cancer prevention, diagnosis, and treatment, mortality by cancer is in second place. Objectives: The design of novel 2-substituted benzimidazole modelled by QSAR study. Molecular docking studies on the novel derivatives and synthesis characterization and evaluation of the anticancer activity of the novel derivatives against breast cancer cell line MCF 7. Methods: We designed 10 novel benzimidazole derivatives modeled by 2D QSAR. From the ten compounds by applying insilico tools of ADME properties and toxicity and through molecular docking on Tyrosine Kinase (PDB ID: 2SRC). Compound 2AD showed the highest dock score of -9.5 kcal/mol followed by 2 BD and 2GD (-9.3kcal/mol) Molecular dynamic simulation studies were conducted using CABSflex an online molecular dynamic simulation tool. Six compounds were selected for synthesis. The synthesized compounds were characterized and the invitro pharmacological activity was tested on MCF-7 cell line by MTT assay. Results: The compounds 2AD and 2GD showed good percentage inhibition on MCF-7 cell line withIC50 values of 2.757 µg/ml and 2.875 µg/ml respectively. Conclusion: The novel 2-substituted benzimidazole derivatives are good lead compounds for cancer therapy. Optimization of these compounds will be providing more target-specific anticancer agents.

Identifying Potential SOS1 Inhibitors via Virtual Screening of Multiple Small Molecule Libraries against KRAS-SOS1 Interaction.

The RAS-MAPK signaling pathway, crucial for cell proliferation and differentiation, involves key proteins KRAS and SOS1. Mutations in the KRAS and SOS1 genes are implicated in various cancer types, including pancreatic, lung, and juvenile myelomonocytic leukemia. There is considerable interest in identifying inhibitors targeting KRAS and SOS1 to explore potential therapeutic strategies for cancer treatment. In this study, advanced in silico techniques were employed to screen small molecule libraries at this interface, leading to the identification of promising lead compounds as potential SOS1 inhibitors. Comparative analysis of the average binding free energies of these predicted potent compounds with known SOS1 small molecule inhibitors revealed that the identified compounds display similar or even superior predicted binding affinities compared to the known inhibitors. These findings offer valuable insights into the potential of these compounds as candidates for further development as effective anti-cancer agents.

Screening approach by a combination of computational and in vitro experiments: identification of fluvastatin sodium as a potential SIRT2 inhibitor.

Sirtuins (SIRTs) are NAD+-dependent deacetylases that play various roles in numerous pathophysiological processes, holding promise as therapeutic targets worthy of further investigation. Among them, the SIRT2 subtype is closely associated with tumorigenesis and malignancies. Dysregulation of SIRT2 activation can regulate the expression levels of related genes in cancer cells, leading to tumor occurrence and metastasis. In this study, we used computer simulations to screen for novel SIRT2 inhibitors from the FDA database, based on which 10 compounds with high docking scores and good interactions were selected for in vitro anti-pancreatic cancer metastasis testing and enzyme binding inhibition experiments. The results showed that fluvastatin sodium may possess inhibitory activity against SIRT2. Subsequently, fluvastatin sodium was subjected to molecular docking experiments with various SIRT isoforms, and the combined results from Western blotting experiments indicated its potential as a SIRT2 inhibitor. Next, molecular docking, molecular dynamics (MD) simulations, and binding free energy calculations were performed, revealing the binding mode of fluvastatin sodium at the SIRT2 active site, further validating the stability and interaction of the ligand-protein complex under physiological conditions. Overall, this study provides a systematic virtual screening workflow for the discovery of SIRT2 activity inhibitors, identifies the potential inhibitory effect of fluvastatin sodium as a lead compound on SIRT2, and opens up a new direction for developing highly active and selectively targeted SIRT2 inhibitors.

Novel binuclear copper(II) complexes with sulfanylpyrazole ligands: Synthesis, crystal structure, fungicidal, cytostatic and cytotoxic activity.

New binuclear Cu(II) tetraligand complexes (six examples) with sulfanylpyrazole ligands were synthesized. EPR Studies have shown that in solution the complexes are transformed to the mononuclear one. Fungicidal properties against Candida albicans were found for the Cu complexes with benzyl and phenyl substituents. An in vitro evaluation of the cytotoxic properties of copper chelates against Hek293, Jurkat, MCF-7, and THP-1 cells identified the copper complex with the cyclohexylsulfanyl substituent in the pyrazole core as the lead compound, whereas the copper complex without a sulfur atom in the pyrazole ligand had virtually no cytotoxic or fungicidal activity. The lead Cu(II) complex was more active than cisplatin. Effect of S-containing Cu complex on apoptosis and cell cycle distribution has been investigated as well.

Designed Mannosylerythritol Lipid Analogues Exhibiting both Selective Cytotoxicity against Human Skin Cancer Cells and Recovery Effects on Damaged Skin Cells.

Mannosylerythritol lipids (MELs) are a class of amphipathic molecules bearinga hydrophilic 4-O-β-D-mannopyranosyl-D-erythritol skeleton. Here, we designed and synthesized four kinds of MEL analogues R-MEL-A ([2R,3S]-erythritol type), S-mannosylthreitol lipid (MTL)-A ([2S,3S]-threitol type), R-MTL-A ([2R,3R]-threitol type), and α-S-MEL-A ([2S,3R]-erythritol type) using our previously reported boron-mediated aglycon delivery (BMAD) method and a neighboring group assisted glycosylation method. The selective cytotoxicity of the target compounds against cancer cells was evaluated, with R-MTL-A showing the highest selective cytotoxicity against human skin squamous carcinoma HSC-5 cells. Our findings suggest that R-MTL-A induces necrosis-like cell death against HSC-5 cells by decreasing cell membrane fluidity. R-MTL-A also exhibits an efficient recovery effect on damaged skin cells, indicating that R-MTL-A has potential as a lead compound for new cosmeceuticals with both cancer cell-selective toxicity and recovery effects on damaged skin cells.

Development of Clarstatin, a Novel Drug Lead for the Therapy of Autoimmune Uveitis

We describe the design, synthesis, and activity of a potent thiourea-bridged backbone cyclic peptidomimetic known as Clarstatin, comprising a 5-amino acid sequence (Q/D)1-(R/K)2-X3-X4-A5-(Gln/Asp)1-(Arg/Lys)2-AA3-AA4-Ala5-based on a motif called “shared epitope (SE)”, specifically present in specific alleles of the HLA-DRB1 gene. This SE binds to a particular site within the proline reach domain (P-domain) of the cell surface-calreticulin (CS-CRT). CS-CRT is a multifunctional endoplasmic reticulum (ER) calcium-binding protein that is located on the cell surface of T cells and triggers innate immune signaling, leading to the development of inflammatory autoimmune diseases. The development of Clarstatin was based on the parent peptide W-G-D1-K2-S3-G4-A5- derived from the active region of the SE. Following the design based on the cycloscan method, the synthesis of Clarstatin was performed by the Fmoc solid phase peptide synthesis (SPPS) method, purified by HPLC to 96% homogeneity, and its structure was confirmed by LC-MS. Clarstatin reduced calcium levels in Jurkat lymphocyte cultures, ameliorated uveitis in vivo in the experimental autoimmune uveitis (EAU) mice model, and was safe upon acute toxicity evaluation. These findings identify Clarstatin as a promising lead compound for future drug development as a novel class of therapeutic agents in the therapy of uveitis.

Pharmacological Perspectives of 2‐alkoxy‐3‐Cyanopyridine Scaffolds: An Up‐to‐Date Review

AbstractThe 2‐alkoxy‐3‐cyanopyridine derivatives’ straightforward synthesis, ease of structural manipulation, and variety of intriguing biological activity continue to captivate medicinal chemists. A substantial body of research has demonstrated that these derivatives exhibit several intriguing biological characteristics, including anticancer, antibacterial, antidiabetic, antioxidant, vasorelaxant, antiviral, and anti‐inflammatory effects. Based on the basic skeleton of 2‐alkoxy‐3‐cyanopyridine, some lead compounds have been prepared with varied pharmaceutical characteristics. These served as excellent models for the development of novel medications since they showed potential in vitro and in vivo action against several cell lines that were both drug‐susceptible and drug‐resistant. To expand the use of 2‐alkoxy‐3‐cyanopyridine in biomedicine, though, a lot more efforts are essential. To combat medication resistance and boost specificity, potential hybrids that unite the 2‐alkoxy‐3‐cyanopyridine moiety with other pharmacophores are indeed required. This review offers a summary of pharmacological screening, including studies of pertinent structure‐activity connections, action mechanisms, and potential therapeutic use.

Chemoproteomics Identifies State-Dependent and Proteoform-Selective Caspase-2 Inhibitors.

Caspases are a highly conserved family of cysteine-aspartyl proteases known for their essential roles in regulating apoptosis, inflammation, cell differentiation, and proliferation. Complementary to genetic approaches, small-molecule probes have emerged as useful tools for modulating caspase activity. However, due to the high sequence and structure homology of all 12 human caspases, achieving selectivity remains a central challenge for caspase-directed small-molecule inhibitor development efforts. Here, using mass spectrometry-based chemoproteomics, we first identify a highly reactive noncatalytic cysteine that is unique to caspase-2. By combining both gel-based activity-based protein profiling (ABPP) and a tobacco etch virus (TEV) protease activation assay, we then identify covalent lead compounds that react preferentially with this cysteine and afford a complete blockade of caspase-2 activity. Inhibitory activity is restricted to the zymogen or precursor form of monomeric caspase-2. Focused analogue synthesis combined with chemoproteomic target engagement analysis in cellular lysates and in cells yielded both pan-caspase-reactive molecules and caspase-2 selective lead compounds together with a structurally matched inactive control. Application of this focused set of tool compounds to stratify the functions of the zymogen and partially processed (p32) forms of caspase-2 provide evidence to support that caspase-2-mediated response to DNA damage is largely driven by the partially processed p32 form of the enzyme. More broadly, our study highlights future opportunities for the development of proteoform-selective caspase inhibitors that target nonconserved and noncatalytic cysteine residues.

A new gold(I) phosphine complex induces apoptosis in prostate cancer cells by increasing reactive oxygen species.

Thioredoxin reductase (TrxR) is a pivotal regulator of redox homeostasis. It is frequently overexpressed in various cancer cells, including prostate cancer, making it a promising target for the development of anti-cancer drugs. In this study, we screened a series of newly designed complexes of gold(I) phosphine. Specifically, Compound 5 exhibited the highest cytotoxicity against prostate cancer cells and demonstrated stronger antitumor effects than commonly used drugs, such as cisplatin and auranofin. Importantly, our mechanistic study revealed that Compound 5 effectively inhibits the TrxR system in vitro. Additionally, Compound 5 promoted intracellular accumulation of reactive oxygen species (ROS), leading to mitochondrial dysfunction and irreversible apoptosis in prostate cancer cells. Our in vivo xenograft study further demonstrated that Compound 5 has excellent antitumor activity against prostate cancer cells, but does not cause severe side effects. These findings provide a promising lead Compound for the development of novel antitumor agents targeting prostate cancer and offer a valuable tool for investigating biological pathways involving TrxR and ROS modulation.

Acute toxicity appraisal of Saussurea heteromalla extract and development of its chemotherapeutic herbal dosage form.

Ethnopharmacological relevance of Saussurea species for anti-cancer compounds instigated us to develop chemotherapeutic herbal tablets. This study was an ongoing part of our previous research based on the scientific evaluation of Saussurea heteromalla (S. heteromalla) for anti-cancer lead compounds. In the current study, S. heteromalla herbal tablets (500 /800 mg) were designed and evaluated for anti-cancer activity. Arctigenin was found as a bioactive lead molecule with anti-cancer potential for cervical cancer. The in vitro results on the HeLa cell line supported the ethnopharmacological relevance and traditional utilization of S. heteromalla and provided the scientific basis for the management of cervical cancer as proclaimed by traditional practitioners in China. LD50 of the crude extract was established trough oral acute toxicity profiling in mice, wherein the minimum lethal dose was noticed as higher than 1000 mg/kg body weight orally. Chromatographic fingerprint analysis ensured the identity and consistency of S. heteromalla in herbal tablets in terms of standardization of the herbal drug. About 99.15% of the drug (S. heteromalla crude extract) was recovered in herbal tablets (RSD: 0.45%). In vitro drug release profile was found to be more than 87% within 1 h, which was also correlated with different mathematical kinetic models of drug release (r2 = 0.992), indicating that drug release from matrix tablets into the blood is constant throughout the delivery. The dosage form was found stable after an accelerated stability parameters study which may be used for anti-cervical cancer therapy in the future, if it qualifies successful preclinical investigation parameters.

Kamebakaurin Suppresses Antigen-Induced Mast Cell Activation by Inhibition of FcεRI Signaling Pathway.

Kamebakaurin is an active constituent of both Rabdosia japonica and Rabdosia excisa, which are utilized in Chinese traditional medicine for improving symptoms in patients with allergies. We investigated the molecular mechanisms of the anti-allergic effects of kamebakaurin using BMMCs. The degranulation ratio, histamine release, and the interleukin (IL)-4, leukotriene B4 (LTB4), and cysteinyl leukotriene productions on antigen-triggered BMMC were investigated. Additionally, the effects of kamebakaurin on signal transduction proteins were examined by Western blot and binding to the Syk and Lyn kinase domain was calculated. The effects of kamebakaurin on antigen-induced hyperpermeability were investigated using mouse model. At 10 μ<sc>m</sc>, kamebakaurin partially inhibited degranulation, histamine release, and IL-4 production. At 30 μ<sc>m</sc>, kamebakaurin partially reduced LTB4 and cysteinyl leukotriene productions and suppressed degranulation, histamine release, and IL-4 production. Phosphorylation of both Syk Y519/520 and its downstream protein, Gab2, was reduced by kamebakaurin, and complete inhibition was observed with 30 μ<sc>m</sc> kamebakaurin. In contrast, phosphorylation of Erk was only partially inhibited, even in the presence of 30 μ<sc>m</sc> kamebakaurin. Syk Y519/520 is known to be auto-phosphorylated via intramolecular ATP present in its own ATP-binding site, and this auto-phosphorylation triggers degranulation, histamine release, and IL-4 production. Docking simulation study indicated kamebakaurin blocked ATP binding to the ATP-binding site in Syk. Therefore, inhibition of Syk auto-phosphorylation by kamebakaurin binding to the Syk ATP-binding site appeared to cause a reduction of histamine release and IL-4 production. Kamebakaurin inhibited antigen-induced vascular hyperpermeability in a dose-dependent fashion but did not reduce histamine-induced vascular hyperpermeability. Kamebakaurin ameliorates allergic symptoms via inhibition of Syk phosphorylation; thus, kamebakaurin could be a lead compound for the new anti-allergic drug.

Discovery of Novel Pyridazine Herbicides Targeting Phytoene Desaturase with Scaffold Hopping.

Phytoene desaturase (PDS) is a critical functional enzyme in blocking ζ-carotene biosynthesis and is one of the bleaching herbicide targets. At present, norflurazon (NRF) is the only commercial pyridazine herbicide targeting PDS. Therefore, developing new and diverse pyridazine herbicides targeting PDS is urgently required. In this study, diflufenican (BF) was used as the lead compound, and a scaffold-hopping strategy was employed to design and synthesize some pyridazine derivatives based on the action mode of BF and PDS. The preemergence herbicidal activity tests revealed that compound 6-chloro-N-(2,4-difluorophenyl)-3-(3-(trifluoromethyl)phenoxy)pyridazine-4-carboxamide (B1) with 2,4-diF substitution in the benzeneamino ring showed 100% inhibition rates against the roots and stems of Echinochloa crus-galli and Portulaca oleracea at 100 μg/mL, superior to the inhibition rates of BF. Meanwhile, compound B1 demonstrated excellent postemergence herbicidal activity against broadleaf weeds, which was similar to that of BF (inhibition rate of 100%) but superior to that of NRF. This indicated that 6-Cl in the pyridazine ring is the key group for postemergence herbicidal activity. In addition, compound B1 could induce downregulation of PDS gene expression, 15-cis-phytoene accumulation, and Y(II) deficiency and prevent photosynthesis. Therefore, B1 can be considered as a promising candidate for developing high-efficiency PDS inhibitors.

Recent Developments in the Antimicrobial Potential of Some Nitrogenous Heterocycles and their SAR Studies: A Review.

Infection remains a significant global health concern, with millions of new cases and deaths occurring due to infectious diseases. Currently, chemoprophylaxis and chemotherapy are the primary treatments, but side effects and toxicities pose challenges. Pathogenic microorganisms have developed resistance to antimicrobial medications. Nitrogen containing heterocyclic scaffolds possess the potential in drug discovery and are explored in various fields like pharmaceuticals, cosmetics, and agrochemicals. To minimize antimicrobial drug resistance, there is a need to design potent, safer antimicrobial lead compounds with higher selectivity and minimal cytotoxicity. The present review aims to outline several recent developments in medicinal chemistry aspect of nitrogenous heterocyclic derivatives with the following purposes: (1) To cast light on the recent literature reports of the last eight years ranging from 2015 to 2023 describing anti-microbial potential of nitrogen-containing heterocyclic derivatives which includes pyrazole, pyrazoline, imidazole, tetrazole and quinoline; (2) To brief the recent developments in the medicinal chemistry of nitrogenous heterocyclic derivatives that is directed towards their anti-microbial profile; (3) To summarize the complete correlation of structural features of nitrogenous heterocyclic molecules with the pharmacological action including in silico as well as mechanistic studies to provide thoughts accompanying the generation of lead molecules. Antimicrobial potential of nitrogenous heterocyclic molecules has been displayed by relating the structural features of various lead candidates with their in vitro as well as in vivo antimicrobial outcomes. In contrast, in silico computational analysis from different articles also helped to predict the SAR of potent molecules. Nitrogen containing heterocycles are involved in a range of natural to synthetic analogues with keen antimicrobial potency. It is an emerging need to generate new nitrogenous heterocyclic molecules in order to tackle the drug resistance in micro-organisms with more targeted selectivity as well as specificity. To limit the side effects associated with them and to combat the microbes acquired resistance towards the current drug regimen, novel nitrogenous heterocycle based antimicrobial agents are essential to be developed. This review connects the structural units present in lead compounds with their promising antimicrobial action.