JNK3, a brain-specific stress-activated protein kinase, plays a critical role in Alzheimer's disease pathogenesis through phosphorylation of Tau and APP. This study aimed to develop selective JNK3 inhibitors based on a pyrazole scaffold, focusing on (E)-1-(2-aminopyrimidin-4-yl)-4-styryl-1H-pyrazole-3-carboxamide derivatives. Through systematic structural modifications and extensive SAR analysis, we identified compounds 24a and 26a as highly potent JNK3 inhibitors, with IC50 values of 12 and 19 nM, respectively. Especially, 24a revealed its potent and selective inhibition of JNK3, coupled with inhibition of the GSK3α/β kinases involved in Tau phosphorylation. In vitro studies revealed significant neuroprotective effects against Aβ1-42-induced toxicity in primary neuronal cells and western blot analyses confirmed the compounds' ability to mitigate Aβ1-42-induced c-Jun and APP phosphorylation, suggesting a multi-faceted approach to neuroprotection. Docking studies validated the retention of optimal interactions within the JNK3 binding pocket. Importantly, BBB PAMPA assays and ADME predictions indicated favorable blood-brain barrier permeability and pharmacokinetic profiles for the lead compounds. These findings represent a significant advancement in the development of selective JNK3 inhibitors, providing a strong foundation for further preclinical development of potential Alzheimer's disease therapeutics.

We report herein the potential of colony-stimulating factor-1 receptor (CSF1R) inhibitors as therapeutic agents in neuroinflammatory diseases, with a focus on Alzheimer's disease (AD). Employing a carefully modified scaffold, N-(4-heterocycloalkyl-2-cycloalkylphenyl)-5-methylisoxazole-3-carboxamide, we identify highly selective and potent CSF1R inhibitors─7dri and 7dsi. Molecular docking studies shed light on the binding modes of these key compounds within the CSF1R binding site. Remarkably, kinome-wide selectivity assessment underscores the impressive specificity of 7dri for CSF-1R. Notably, 7dri emerges as a potent CSF-1R inhibitor with favorable cellular activity and minimal cytotoxicity among the synthesized compounds. Demonstrating efficacy in inhibiting CSF1R phosphorylation in microglial cells and successfully mitigating neuroinflammation in an in vivo LPS-induced model, 7dri establishes itself as a promising antineuroinflammatory agent.

This study explores the potential of CSF-1R inhibitors as therapeutic agents for neurodegenerative diseases. CSF1R, a receptor tyrosine kinase primarily expressed in macrophage lineages, plays a pivotal role in regulating various cellular processes. Recent research highlights the significance of CSF-1R inhibition in mitigating neuroinflammation, particularly in Alzheimer's disease, where microglial overactivation contributes to neurodegeneration. The research reveals a series of N-(5-amido-2-methylphenyl)-5-methylisoxazole-3-carboxamide CSF-1R inhibitors, where compounds 7d, 7e, and 9a exhibit outstanding inhibitory activities and selectivity, with IC50 values of 33, 31, and 64 nM, respectively. These most promising compounds in this series were profiled for cellular potency and subjected to in vitro pharmacokinetic profiling. These inhibitors exhibit minimal cytotoxicity, even at higher concentrations, and possess promising blood-brain barrier permeability, making them potential candidates for central nervous system diseases. The investigation into the in vitro ADME properties, including plasma and microsomal stability, reveals that these CSF-1R inhibitors maintain their structural integrity and plasma concentration. This resilience positions them for further development as therapeutic agents for neurodegenerative diseases.

JNK3 is a key factor driving the pathophysiology of neuronal apoptosis. Since demonstrating the therapeutic potential of JNK3 inhibitors in Alzheimer's disease, we aimed to broaden their chemical diversity for drug development. In continuation with our previous research, a series of compounds with the tetrahydrocyclopenta [d]imidazole scaffold as a core moiety was developed as JNK3 inhibitors based on in silico modeling analysis. The biochemical kinase assay results revealed that the JNK3 inhibitory effects and isoform selectivity of the compounds developed in this study were significantly higher than that of previously developed inhibitors. In particular, the IC50 values of compounds 18c, 19c, 22b, and 26c, which exhibited excelled isoform selectivity, against JNK3 were 0.716, 0.564, 0.379, and 0.779 nM, respectively, which were more potent than those of any known JNK3 inhibitors. Additionally, compounds 18c, 18c, 22b, and 22c effectively protected the neuronal cells against amyloid beta-induced apoptosis. Docking studies indicated that the tetrahydrocyclopenta[d]imidazole scaffold retained all the optimal interactions. Meanwhile, BBB PAMPA and ADME prediction suggested that the tested compounds had a favorable BBB permeability and pharmacokinetic profile. Therefore, the tetrahydrocyclopenta[d]imidazole scaffold is a promising candidate for developing JNK3 inhibitors. In particular, compound 22b is a potential starting point for the preclinical optimization of novel JNK3 inhibitors.

The presence of spoilage and pathogenic microorganisms is a concern for the safety of apples. In the present study, we evaluated the hygienic status of electrolyzed water (EW)- or ozonated water (OW)-washed apples, which were stored over 2 weeks under the combination of 2 different temperatures (25 and 30°C) and 2 different relative humidity (RH) conditions (85 and 90%). The average numbers of bacteria or fungi from unwashed and washed apples (EW or OW) did not show statistically significant differences at storage for 0, 1, or 2 weeks and had an increased tendency as the storage temperature, RH, and period increased. Identification of fungal isolates from apples revealed 3 main genera (Fusarium sp., Trichoderma sp., and Alternaria sp.) together with 8 minor genera (Meyerozyma sp., Aspergillus sp., Glomerella sp., Neofusicoccum sp., Penicillium sp., Hypoxylon sp., Talaromyces sp., and Coprinellus sp.). Moreover, sensory tests using EW- or OW-washed apples showed that OW did not significantly affect 5 quality characteristics (appearance, taste, flavor, texture, and overall acceptability). Our data suggest that EW or OW washing did not significantly reduce the levels of microorganisms on apples relative to the unwashed and that EW or OW washing did not deteriorate the quality of washed apples.

We have been developing new inhibitors for c-Jun N-terminal kinase 3 (JNK3) as a potential treatment for Alzheimer's disease (AD). We identified potential JNK3 inhibitors through pharmacodynamic optimization studies, including benzimidazole compounds 2 and 3, but their unreliable pharmacokinetic properties led us to develop carbamate inhibitors 2h and 3h. In vitro studies validated carbamate inhibitors 2h and 3h as potent and highly selective JNK3 inhibitors with favorable pharmacokinetic profiles. Oral administration of 2h and 3h to both APP/PS1 and 3xTg AD mouse models improved cognitive function, indicating their potential as effective treatments for Alzheimer's disease. Carbamate JNK3 inhibitor 3h, in particular, restored cognitive function to near-normal levels in the 3xTg mice model of AD and led to pTau reduction in the hippocampal tissues of 3xTg-AD mice during in vivo behavioral evaluations. We intend to further develop these carbamate JNK3 inhibitors in preclinical studies as a potential first-in-class treatment for AD.

Despite innumerable efforts to develop effective therapeutics, it is difficult to achieve breakthrough treatments for Alzheimer's disease (AD), and the main reason is probably the absence of a clear target. Here, we reveal c-Jun N-terminal kinase 3 (JNK3), a protein kinase explicitly expressed in the brain and involved in neuronal apoptosis, with a view toward providing effective treatment for AD. For many years, we have worked on JNK3 inhibitors and have discovered 2-aryl-1-pyrimidinyl-1H-imidazole-5-yl acetonitrile-based JNK3 inhibitors with superb potency (IC50 < 1.0 nM) and excellent selectivity over other protein kinases including isoforms JNK1 (>300 fold) and JNK2 (∼10 fold). Based on in vitro biological activity and DMPK properties, the lead compounds were selected for further in vivo studies. We confirmed that repeat administration of JNK3 inhibitors improved cognitive memory in APP/PS1 and the 3xTg mouse model. Overall, our results show that JNK3 could be a potential target protein for AD.

JNK3 is a key driver in the pathophysiology of neuronal apoptosis. Broadening the chemical diversity of JNK3 inhibitors in drug development has been our goal since we found that JNK3 inhibitors could be suitable for treating Alzheimer’s disease. As a continuation of our research, a series of compounds with tetrahydrocyclopenta[d]imidazole scaffold as a core moiety were developed as JNK3 inhibitors based on in silico modelling analysis. Biological results indicated that these compounds exhibited a significantly enhanced inhibition against JNK3 in biochemical kinases assays, along with superb isoform selectivity compared with previously revealed compounds. In particular, compounds 18c , 19c , 22b, and 26c exhibited potent inhibition activities with IC 50 values of 0.716, 0.564, 0.397, and 0.779 nM, respectively, outperforming that of any known JNK3 inhibitors with excellent isoform selectivity. Additionally, compounds 18c , 19c , 22b, and 26c effectively protected Aβ induced neuronal apoptosis, and inhibited c-Jun phosphorylation in a dose-dependent manner. Docking studies indicated that tetrahydrocyclopenta[d]imidazole scaffold indeed retained all the proper interactions and ADME prediction suggested that tested compounds had a favourable safety profile. Therefore, tetrahydrocyclopenta[d]imidazole scaffold could serve as a promising JNK3 inhibitors, and compound 22b in particular could be served as a starting point for preclinical optimization.

Cancer continues to be one of the world's most severe public health issues. Polo-like kinase 1 (PLK1) is one of the most studied members of the polo-like kinase subfamily of serine/threonine protein kinases. PLK1 is a key mitotic regulator responsible for cell cycle processes, such as mitosis initiation, bipolar mitotic spindle formation, centrosome maturation, the metaphase to anaphase transition, and mitotic exit, whose overexpression is often associated with oncogenesis. Moreover, it is also involved in DNA damage response, autophagy, cytokine signaling, and apoptosis. Due to its fundamental role in cell cycle regulation, PLK1 has been linked to various types of cancer onset and progression, such as lung, colon, prostate, ovary, breast cancer, melanoma, and AML. Hence, PLK1 is recognized as a critical therapeutic target in the treatment of various proliferative diseases. PLK1 inhibitors developed in recent years have been researched and studied through clinical trials; however, most of them have failed because of their toxicity and poor therapeutic response. To design more potent and selective PLK1 inhibitors, we performed a receptor-based hybrid 3D-QSAR study of two datasets, possessing similar common scaffolds. The developed hybrid CoMFA (q2 = 0.628, r2 = 0.905) and CoMSIA (q2 = 0.580, r2 = 0.895) models showed admissible statistical results. Comprehensive, molecular docking of one of the most active compounds from the dataset and hybrid 3D-QSAR studies revealed important active site residues of PLK1 and requisite structural characteristics of ligand to design potent PLK1 inhibitors. Based on this information, we have proposed approximately 38 PLK1 inhibitors. The newly designed PLK1 inhibitors showed higher activity (predicted pIC50) than the most active compounds of all the derivatives selected for this study. We selected and synthesized two compounds, which were ultimately found to possess good IC50 values. Our design strategy provides insight into development of potent and selective PLK1 inhibitors.

Polo-like kinase 1 (PLK1) plays an important role in cell cycle progression and proliferation in cancer cells. PLK1 also contributes to anticancer drug resistance and is a valuable target in anticancer therapeutics. To identify additional effective PLK1 inhibitors, we performed QSAR studies of two series of known PLK1 inhibitors and proposed a new structure based on a hybridized 3D-QSAR model. Given the hybridized 3D-QSAR models, we designed and synthesized 4-benzyloxy-1-(2-arylaminopyridin-4-yl)-1H-pyrazole-3-carboxamides, and we inspected its inhibitory activities to identify novel PLK1 inhibitors with decent potency and selectivity.

As members of the MAPK family, c-Jun-N-terminal kinases (JNKs) regulate the biological processes of apoptosis. In particular, the isoform JNK3 is expressed explicitly in the brain at high levels and is involved in the pathogenesis of neurodegenerative diseases such as Alzheimer’s disease (AD) and Parkinson’s disease (PD). In this study, we prepared a series of five 6-dihydroxy-1H-benzo[d]imidazoles as JNK3 inhibitors and found them have potential as neuroprotective agents. Following a previous lead scaffold, benzimidazole moiety was modified with various aryl groups and hydroxylation, and the resulting compounds exhibited JNK3 inhibitory activity with improved potency and selectivity. Out of 37 analogues synthesized, (S)-cyclopropyl(3-((4-(2-(2,3-dihydrobenzo[b][1,4]dioxin -6-yl)-5,6-dihydroxy-1H-benzo[d]imidazol-1-yl)pyrimidin-2-yl)amino) piperidin-1-yl)methanone (35b) demonstrated the highest JNK3 inhibition (IC50 = 9.7 nM), as well as neuroprotective effects against Aβ-induced neuronal cell death. As a protein kinase inhibitor, it also showed excellent selectivity over other protein kinases including isoforms JNK1 (>1000 fold) and JNK2 (−10 fold).