Examining Hemin and its Derivatives: Induction of Heme-Oxygenase-1 Activity and Oxidative Stress in Breast Cancer Cells through Collaborative Experimental Analysis and Molecular Dynamics Simulations.

Hemin triggers intracellular reactive oxygen species (ROS) accumulation and enhances heme oxygenase-1 (HOX-1) activity, indicating its potential as an anticancer agent, though precise control of its intracellular levels is crucial. The study explores the impact of hemin and its derivatives, hemin-tyrosine, and hemin-styrene (H-Styr) conjugates on migration, HOX-1 expression, specific apoptosis markers, mitochondrial functions, and ROS generation in breast cancer cells. Molecular docking and dynamics simulations were used to understand the interactions among HOX-1, heme, and the compounds. Hemin outperforms its derivatives in inducing HOX-1 expression, exhibiting pro-oxidative effects and reducing cell migration. Molecular simulations show that heme binds favorably to HOX-1, followed by the other compounds, primarily through van der Waals and electrostatic forces. However, only van der Waals forces determine the H-Styr complexation. These interactions, influenced by metalloporphyrin characteristics, provide insights into HOX-1 regulation and ROS generation, potentially guiding the development of breast cancer therapies targeting oxidative stress.

Systematic Review of Naturally Derived Substances That Act as Inhibitors of the Nicotine Metabolizing Enzyme Cytochrome P450 2A6.

Tobacco smoking has been highlighted as a major health challenge in modern societies. Despite not causing death directly, smoking has been associated with several health issues, such as cardiovascular diseases, respiratory disorders, and several cancer types. Moreover, exposure to nicotine during pregnancy has been associated with adverse neurological disorders in babies. Nicotine Replacement Therapy (NRT) is the most common strategy employed for smoking cessation, but despite its widespread use, NRT presents with low success and adherence rates. This is attributed partially to the rate of nicotine metabolism by cytochrome P450 2A6 (CYP2A6) in each individual. Nicotine addiction is correlated with the high rate of its metabolism, and thus, novel strategies need to be implemented in NRT protocols. Naturally derived products are a cost-efficient and rich source for potential inhibitors, with the main advantages being their abundance and ease of isolation. This systematic review aims to summarize the natural products that have been identified as CYP2A6 inhibitors, validated through in vitro and/or in vivo assays, and could be implemented as nicotine metabolism inhibitors. The scope is to present the different compounds and highlight their possible implementation in NRT strategies. Additionally, this information would provide valuable insight regarding CYP2A6 inhibitors, that can be utilized in drug development via the use of in silico methodologies and machine-learning models to identify new potential lead compounds for optimization and implementation in NRT regimes.

ERAP Inhibitors in Autoimmunity and Immuno-Oncology: Medicinal Chemistry Insights.

Endoplasmic reticulum aminopeptidases ERAP1 and 2 are intracellular aminopeptidases that trim antigenic precursors and generate antigens presented by major histocompatibility complex class I (MHC-I) molecules. They thus modulate the antigenic repertoire and drive the adaptive immune response. ERAPs are considered as emerging targets for precision immuno-oncology or for the treatment of autoimmune diseases, in particular MHC-I-opathies. This perspective covers the structural and biological characterization of ERAP, their relevance to these diseases and the ongoing research on small-molecule inhibitors. We describe the chemical and pharmacological space explored by medicinal chemists to exploit the potential of these targets given their localization, biological functions, and family depth. Specific emphasis is put on the binding mode, potency, selectivity, and physchem properties of inhibitors featuring diverse scaffolds. The discussion provides valuable insights for the future development of ERAP inhibitors and analysis of persisting challenges for the translation for clinical applications.

In Vitro Toxicological Insights from the Biomedical Applications of Iron Carbide Nanoparticles in Tumor Theranostics: A Systematic Review and Meta-Analysis.

(1) Background: Despite the encouraging indications regarding the suitability (biocompatibility) of iron carbide nanoparticles (ICNPs) in various biomedical applications, the published evidence of their biosafety is dispersed and relatively sparse. The present review synthesizes the existing nanotoxicological data from in vitro studies relevant to the diagnosis and treatment of cancer. (2) Methods: A systematic review was performed in electronic databases (PubMed, Scopus, and Wiley Online Library) on December 2023, searching for toxicity assessments of ICNPs of different sizes, coatings, and surface modifications investigated in immortalized human and murine cell lines. The risk of bias in the studies was assessed using the ToxRTool for in vitro studies. (3) Results: Among the selected studies (n = 22), cell viability emerged as the most frequently assessed cellular-level toxicity endpoint. The results of the meta-analysis showed that cell models treated with ICNPs had a reduced cell viability (SMD = -2.531; 95% CI: -2.959 to -2.109) compared to untreated samples. A subgroup analysis was performed due to the high magnitude of heterogeneity (I2 = 77.1%), revealing that ICNP concentration and conjugated ligands are the factors that largely influence toxicity (p < 0.001). (4) Conclusions: A dose-dependent cytotoxicity of ICNP exposure was observed, regardless of the health status of the cell, tested organism, and NP size. Inconsistent reporting of ICNP physicochemical properties was noted, which hinders comparability among the studies. A comprehensive exploration of the available in vivo studies is required in future research to assess the safety of ICNPs' use in bioimaging and cancer treatment.

Identification of two novel chemical classes of Autotaxin (ATX) inhibitors using Enalos Asclepios KNIME nodes.

Autotaxin is a secreted lysophospholipase D which is a member of the ectonucleotide pyrophosphatase/phosphodiesterase family converting extracellular lysophosphatidylcholine and other non-choline lysophospholipids, such as lysophosphatidylethanolamine and lysophosphatidylserine, to the lipid mediator lysophosphatidic acid. Autotaxin is implicated in various fibroproliferative diseases including interstitial lung diseases, such as idiopathic pulmonary fibrosis and hepatic fibrosis, as well as in cancer. In this study, we present an effort of identifying ATX inhibitors that bind to allosteric ATX binding sites using the Enalos Asclepios KNIME Node. All the available PDB crystal structures of ATX were collected, prepared, and aligned. Visual examination of these structures led to the identification of four crystal structures of human ATX co-crystallized with four known inhibitors. These inhibitors bind to five binding sites with five different binding modes. These five binding sites were thereafter used to virtually screen a compound library of 14,000 compounds to identify molecules that bind to allosteric sites. Based on the binding mode and interactions, the docking score, and the frequency that a compound comes up as a top-ranked among the five binding sites, 24 compounds were selected for in vitro testing. Finally, two compounds emerged with inhibitory activity against ATX in the low micromolar range, while their mode of inhibition and binding pattern were also studied. The two derivatives identified herein can serve as "hits" towards developing novel classes of ATX allosteric inhibitors.

Discovery of the First-in-Class Inhibitors of Hypoxia Up-Regulated Protein†1 (HYOU1) Suppressing Pathogenic Fibroblast Activation.

Fibroblasts are key regulators of inflammation, fibrosis, and cancer. Targeting their activation in these complex diseases has emerged as a novel strategy to restore tissue homeostasis. Here, we present a multidisciplinary lead discovery approach to identify and optimize small molecule inhibitors of pathogenic fibroblast activation. The study encompasses medicinal chemistry, molecular phenotyping assays, chemoproteomics, bulk RNA-sequencing analysis, target validation experiments, and chemical absorption, distribution, metabolism, excretion and toxicity (ADMET)/pharmacokinetic (PK)/in vivo evaluation. The parallel synthesis employed for the production of the new benzamide derivatives enabled us to a) pinpoint key structural elements of the scaffold that provide potent fibroblast-deactivating effects in cells, b) discriminate atoms or groups that favor or disfavor a desirable ADMET profile, and c) identify metabolic "hot spots". Furthermore, we report the discovery of the first-in-class inhibitor leads for hypoxia up-regulated protein 1 (HYOU1), a member of the heat shock protein 70 (HSP70) family often associated with cellular stress responses, particularly under hypoxic conditions. Targeting HYOU1 may therefore represent a potentially novel strategy to modulate fibroblast activation and treat chronic inflammatory and fibrotic disorders.

"Hit" to lead optimization and chemoinformatic studies for a new series of Autotaxin inhibitors.

Robust experimental evidence has highlighted the role of Autotaxin (ATX)/Lysophosphatidic acid (LPA) axis not only in the pathogenesis of chronic inflammatory conditions and especially in fibroproliferative diseases but also in several types of cancer. As a result, different series of substrate-, lipid-based and small-molecule ATX inhibitors have been identified thus far by both academia and pharma. The "crowning achievement" of these drug discovery campaigns was the development and entry of the first-in-class ATX inhibitor (ziritaxestat, GLPG-1690) in advanced clinical trials against idiopathic pulmonary fibrosis. Herein, the potency optimization efforts of a new series of Autotaxin inhibitors, namely 2-substituted-2,6-dihydro-4H-thieno[3,4-c]pyrazol-1-substituted amide, is described using a previously identified novel chemical scaffold as a "hit". The mode of inhibition of the most promising ATX inhibitors was investigated, while their cellular activity, aqueous solubility and cytotoxicity were evaluated. Our pharmacological results were corroborated by chemoinformatic tools (molecular docking and molecular dynamics simulations) deployed, to provide insight into the binding mechanism of the synthesized inhibitors to ATX.

In Silico Identification and Evaluation of Natural Products as Potential Tumor Necrosis Factor Function Inhibitors Using Advanced Enalos Asclepios KNIME Nodes.

Tumor necrosis factor (TNF) is a regulator of several chronic inflammatory diseases, such as rheumatoid arthritis. Although anti-TNF biologics have been used in clinic, they render several drawbacks, such as patients' progressive immunodeficiency and loss of response, high cost, and intravenous administration. In order to find new potential anti-TNF small molecule inhibitors, we employed an in silico approach, aiming to find natural products, analogs of Ampelopsin H, a compound that blocks the formation of TNF active trimer. Two out of nine commercially available compounds tested, Nepalensinol B and Miyabenol A, efficiently reduced TNF-induced cytotoxicity in L929 cells and production of chemokines in mice joints' synovial fibroblasts, while Nepalensinol B also abolished TNF-TNFR1 binding in non-toxic concentrations. The binding mode of the compounds was further investigated by molecular dynamics and free energy calculation studies, using and advancing the Enalos Asclepios pipeline. Conclusively, we propose that Nepalensinol B, characterized by the lowest free energy of binding and by a higher number of hydrogen bonds with TNF, qualifies as a potential lead compound for TNF inhibitors' drug development. Finally, the upgraded Enalos Asclepios pipeline can be used for improved identification of new therapeutics against TNF-mediated chronic inflammatory diseases, providing state-of-the-art insight on their binding mode.

Predicting Cytotoxicity of Metal Oxide Nanoparticles using Isalos Analytics Platform.

A literature curated dataset containing 24 distinct metal oxide (MexOy) nanoparticles (NPs), including 15 physicochemical, structural and assay-related descriptors, was enriched with 62 atomistic computational descriptors and exploited to produce a robust and validated in silico model for prediction of NP cytotoxicity. The model can be used to predict the cytotoxicity (cell viability) of MexOy NPs based on the colorimetric lactate dehydrogenase (LDH) assay and the luminometric adenosine triphosphate (ATP) assay, both of which quantify irreversible cell membrane damage. Out of the 77 total descriptors used, 7 were identified as being significant for induction of cytotoxicity by MexOy NPs. These were NP core size, hydrodynamic size, assay type, exposure dose, the energy of the MexOy conduction band (EC), the coordination number of the metal atoms on the NP surface (Avg. C.N. Me atoms surface) and the average force vector surface normal component of all metal atoms (v⟂ Me atoms surface). The significance and effect of these descriptors is discussed to demonstrate their direct correlation with cytotoxicity. The produced model has been made publicly available by the Horizon 2020 (H2020) NanoSolveIT project and will be added to the project's Integrated Approach to Testing and Assessment (IATA).

Structure-Based Discovery of Novel Chemical Classes of Autotaxin Inhibitors.

Autotaxin (ATX) is a secreted glycoprotein, widely present in biological fluids, largely responsible for extracellular lysophosphatidic acid (LPA) production. LPA is a bioactive growth-factor-like lysophospholipid that exerts pleiotropic effects in almost all cell types, exerted through at least six G-protein-coupled receptors (LPAR1-6). Increased ATX expression has been detected in different chronic inflammatory diseases, while genetic or pharmacological studies have established ATX as a promising therapeutic target, exemplified by the ongoing phase III clinical trial for idiopathic pulmonary fibrosis. In this report, we employed an in silico drug discovery workflow, aiming at the identification of structurally novel series of ATX inhibitors that would be amenable to further optimization. Towards this end, a virtual screening protocol was applied involving the search into molecular databases for new small molecules potentially binding to ATX. The crystal structure of ATX in complex with a known inhibitor (HA-155) was used as a molecular model docking reference, yielding a priority list of 30 small molecule ATX inhibitors, validated by a well-established enzymatic assay of ATX activity. The two most potent, novel and structurally different compounds were further structurally optimized by deploying further in silico tools, resulting to the overall identification of six new ATX inhibitors that belong to distinct chemical classes than existing inhibitors, expanding the arsenal of chemical scaffolds and allowing further rational design.

Synthesis of novel 2-pyrrolidinone and pyrrolidine derivatives and study of their inhibitory activity against autotaxin enzyme.

Autotaxin (ATX), a glycoprotein (~125 kDa) isolated as an autocrine motility factor from melanoma cells, belongs to a seven-membered family of ectonucleotide pyrophosphatase/phosphodiesterase (ENPP), and exhibits lysophospholipase D activity. ATX is responsible for the hydrolysis of lysophosphatidylcholine (LPC) to produce the bioactive lipid lysophosphatidic acid (LPA), which is upregulated in a variety of pathological inflammatory conditions, including fibrosis, cancer, liver toxicity and thrombosis. Given its role in human disease, the ATX-LPA axis is an interesting target for therapy, and the development of novel potent ATX inhibitors is of great importance. In the present work a novel class of ATX inhibitors, optically active derivatives of 2-pyrrolidinone and pyrrolidine heterocycles were synthesized. Some of them exhibited interesting in vitro activity, namely the hydroxamic acid 16 (IC50 700 nM) and the carboxylic acid 40b (IC50 800 nM), while the boronic acid derivatives 3k (IC50 50 nM), 3l (IC50 120 nM), 3 m (IC50 180 nM) and 21 (IC50 35 nM) were found to be potent inhibitors of ATX.

Development and therapeutic potential of autotaxin small molecule inhibitors: From bench to advanced clinical trials.

Several years after its isolation from melanoma cells, an increasing body of experimental evidence has established the involvement of Autotaxin (ATX) in the pathogenesis of several diseases. ATX, an extracellular enzyme responsible for the hydrolysis of lysophosphatidylcholine (LPC) into the bioactive lipid lysophosphatidic acid (LPA), is overexpressed in a variety of human metastatic cancers and is strongly implicated in chronic inflammation and liver toxicity, fibrotic diseases, and thrombosis. Accordingly, the ATX-LPA signaling pathway is considered a tractable target for therapeutic intervention substantiated by the multitude of research campaigns that have been successful in identifying ATX inhibitors by both academia and industry. Furthermore, from a therapeutic standpoint, the entry and the so far promising results of the first ATX inhibitor in advanced clinical trials against idiopathic pulmonary fibrosis (IPF) lends support to the viability of this approach, bringing it to the forefront of drug discovery efforts. The present review article aims to provide a comprehensive overview of the most important series of ATX inhibitors developed so far. Special weight is lent to the design, structure activity relationship and mode of binding studies carried out, leading to the identification of advanced leads. The most significant in vitro and in vivo pharmacological results of these advanced leads are also summarized. Lastly, the development of the first ATX inhibitor entered in clinical trials accompanied by its phase 1 and 2a clinical trial data is disclosed.

In Silico Discovery of Plant-Origin Natural Product Inhibitors of Tumor Necrosis Factor (TNF) and Receptor Activator of NF-κB Ligand (RANKL).

An in silico drug discovery pipeline for the virtual screening of plant-origin natural products (NPs) was developed to explore new direct inhibitors of TNF and its close relative receptor activator of nuclear factor kappa-B ligand (RANKL), both representing attractive therapeutic targets for many chronic inflammatory conditions. Direct TNF inhibition through identification of potent small molecules is a highly desired goal; however, it is often hampered by severe limitations. Our approach yielded a priority list of 15 NPs as potential direct TNF inhibitors that were subsequently tested in vitro against TNF and RANKL. We thus identified two potent direct inhibitors of TNF function with low micromolar IC50 values and minimal toxicity even at high concentrations. Most importantly, one of them (A11) was proved to be a dual inhibitor of both TNF and RANKL. Extended molecular dynamics simulations with the fully automated EnalosMD suite rationalized the mode of action of the compounds at the molecular level. To our knowledge, these compounds constitute the first NP TNF inhibitors, one of which being the first NP small-molecule dual inhibitor of TNF and RANKL, and could serve as lead compounds for the development of novel treatments for inflammatory and autoimmune diseases.

Current Status and Future Prospects of Small-molecule Protein-protein Interaction (PPI) Inhibitors of Tumor Necrosis Factor (TNF) and Receptor Activator of NF-κB Ligand (RANKL).

The overexpression of Tumor Necrosis Factor (TNF) is directly related to the development of several autoimmune diseases, such as rheumatoid and psoriatic arthritis, inflammatory bowel disease, Crohn's disease, refractory asthma, and multiple sclerosis. Receptor Activator of Nuclear Factor Kappa- B Ligand (RANKL) belongs to the TNF family and is the primary mediator of osteoclast-induced bone resorption through interaction with its receptor RANK. The function of RANKL is physiologically inhibited by the action of osteoprotegerin (OPG), which is a decoy receptor that binds to RANKL and prevents the process of osteoclastogenesis. Malfunction among RANK/RANKL/OPG can also result in bone loss diseases, including postmenopausal osteoporosis, rheumatoid arthritis, bone metastasis and multiple myeloma. To disrupt the unwanted functions of TNF and RANKL, current attempts focus on blocking TNF and RANKL binding to their receptors. In this review, we present the research efforts toward the development of low-molecular-weight pharmaceuticals that directly block the detrimental actions of TNF and RANKL.

Hydroxamic Acids Constitute a Novel Class of Autotaxin Inhibitors that Exhibit in Vivo Efficacy in a Pulmonary Fibrosis Model.

Autotaxin (ATX) catalyzes the hydrolysis of lysophosphatidylcholine (LPC) generating the lipid mediator lysophosphatidic acid (LPA). Both ATX and LPA are involved in various pathological inflammatory conditions, including fibrosis and cancer, and have attracted great interest as medicinal targets over the past decade. Thus, the development of novel potent ATX inhibitors is of great importance. We have developed a novel class of ATX inhibitors containing the zinc binding functionality of hydroxamic acid. Such novel hydroxamic acids that incorporate a non-natural δ-amino acid residue exhibit high in vitro inhibitory potency over ATX (IC50 values 50-60 nM). Inhibitor 32, based on δ-norleucine, was tested for its efficacy in a mouse model of pulmonary inflammation and fibrosis induced by bleomycin and exhibited promising efficacy. The novel hydroxamic ATX inhibitors provide excellent tools for the study of the role of the enzyme and could contribute to the development of novel therapeutic agents for the treatment of fibrosis and other chronic inflammatory diseases.

Aqueous Solubility Enhancement for Bioassays of Insoluble Inhibitors and QSPR Analysis: A TNF-α Study.

The aim of this study is to improve the aqueous solubility of a group of compounds without interfering with their bioassay as well as to create a relevant prediction model. A series of 55 potential small-molecule inhibitors of tumor necrosis factor-alpha (TNF-α; SPD304 and 54 analogues), many of which cannot be bioassayed because of their poor solubility, was used for this purpose. The solubility of many of the compounds was sufficiently improved to allow measurement of their respective dissociation constants (Kd). Parameters such as dissolution time, initial state of the solute (solid/liquid), co-solvent addition (DMSO and PEG3350), and sample filtration were evaluated. Except for filtration, the remaining parameters affected aqueous solubility, and a solubilization protocol was established according to these. The aqueous solubility of the 55 compounds in 5% DMSO was measured with this protocol, and a predictive quantitative structure property relationship model was developed and fully validated based on these data. This classification model separates the insoluble from the soluble compounds and predicts the solubility of potential small-molecule inhibitors of TNF-α in aqueous solution (containing 5% DMSO as co-solvent) with an accuracy of 81.2%. The domain of applicability of the model indicates the type of compounds for which estimation of aqueous solubility can be confidently predicted.

Cheminformatics-aided discovery of small-molecule Protein-Protein Interaction (PPI) dual inhibitors of Tumor Necrosis Factor (TNF) and Receptor Activator of NF-κB Ligand (RANKL).

We present an in silico drug discovery pipeline developed and applied for the identification and virtual screening of small-molecule Protein-Protein Interaction (PPI) compounds that act as dual inhibitors of TNF and RANKL through the trimerization interface. The cheminformatics part of the pipeline was developed by combining structure-based with ligand-based modeling using the largest available set of known TNF inhibitors in the literature (2481 small molecules). To facilitate virtual screening, the consensus predictive model was made freely available at: http://enalos.insilicotox.com/TNFPubChem/. We thus generated a priority list of nine small molecules as candidates for direct TNF function inhibition. In vitro evaluation of these compounds led to the selection of two small molecules that act as potent direct inhibitors of TNF function, with IC50 values comparable to those of a previously-described direct inhibitor (SPD304), but with significantly reduced toxicity. These molecules were also identified as RANKL inhibitors and validated in vitro with respect to this second functionality. Direct binding of the two compounds was confirmed both for TNF and RANKL, as well as their ability to inhibit the biologically-active trimer forms. Molecular dynamics calculations were also carried out for the two small molecules in each protein to offer additional insight into the interactions that govern TNF and RANKL complex formation. To our knowledge, these compounds, namely T8 and T23, constitute the second and third published examples of dual small-molecule direct function inhibitors of TNF and RANKL, and could serve as lead compounds for the development of novel treatments for inflammatory and autoimmune diseases.

Development of a Predictive Pharmacophore Model and a 3D-QSAR Study for an in silico Screening of New Potent Bcr-Abl Kinase Inhibitors.

Chronic myelogenous leukemia (CML) is a myeloproliferative disorder, characterized, in most cases, by the presence of the Bcr-Abl fusion oncogene. Bcr-Abl is a constitutively active tyrosine kinase that is responsible for the malignant transformation. Targeting the Bcr-Abl kinase is an attractive treatment strategy for CML. First and second generation Bcr-Abl inhibitors have focused on targeting the ATP-binding domain of the kinase. Mutations in that region are relatively resistant to drug manipulation. Therefore, non-ATP-competitive agents have been recently developed and tested. In the present study, in an attempt to aid the design of new chemotypes with enhanced cytotoxicity against K562 cells, 3D pharmacophore models were generated and 3D-QSAR CoMFA and CoMSIA studies were carried out on the 33 novel Abl kinase inhibitors (E)-α-benzylthio chalcones synthesized by Reddy et al. A five-point pharmacophore with a hydrogen bond acceptor, two hydrophobic groups and two aromatic rings as pharmacophore features, and a statistically significant 3D-QSAR model with excellent predictive power were developed. The pharmacophore model was also used for alignment of the 33 compounds in a CoMFA/CoMSIA analysis. The contour maps of the fields of CoMFA and CoMSIA models were utilized to provide structural insight into how these molecules promote their toxicity. The possibility of using this model for the design of drugs for the treatment of β-thalassemia and sickle cell disease (SCD), since several Bcr-Abl inhibitors are able to promote erythroid differentiation and γ-globin expression in CML cell lines and primary erythroid cells is discussed.

Searching for Novel Janus Kinase-2 Inhibitors Using a Combination of Pharmacophore Modeling, 3D-QSAR Studies and Virtual Screening.

The Janus kinases (JAKs) play a pivotal role in cytokine receptor signaling pathways via activation of downstream signal transducers and activators of transcription (STAT) pathway. Intracellular pathways that include JAKs are critical to immune cell activation and pro-inflammatory cytokine production. Selective inhibitors of JAKs are potentially disease-modifying anti-inflammatory drugs for the treatment of rheumatoid arthritis (RA). Each of the four members of the JAK family plays an individual role in the oncogenesis of the immune system, and therefore, the development of potent and specific inhibitors for each member is needed. Although there is a high sequence homology and structural identity of JAK1 and JAK2, such as a very similar binding mode of inhibitors at the ATPbinding site of enzymes, obvious differences surrounding the JAK1 and JAK2 ATP-binding sites provide a platform for the rational design of JAK2- and JAK1-specific inhibitors. In the present study, a dataset of 33 compounds characterized by a common scaffold of 2-amino-[1,2,4]triazolo[1,5-α]pyridine with well-defined in vitro activity values was computationally explored. Most of the compounds included in the dataset had higher ligand efficiency against JAK2 than JAK1. To improve further the selectivity of these triazolopyridines, Common Pharmacophore Hypotheses (CPHs) were generated and 3D-QSAR studies were carried out on them, in order to comprehend on the molecular features responsible for their selectivity. The proposed computational approach was applied in order to perform an in silico database virtual screening study with the aim to discover novel potent and selective JAK2 inhibitors.

Antiproliferative novel isoxazoles: modeling, virtual screening, synthesis, and bioactivity evaluation.

A series of novel isoxazole derivatives were efficiently synthesized through the adaptation/modification of an in situ synthetic procedure for pyrazoles. All novel compounds were tested against four different cell lines to evaluate their antiproliferative activity. Based on the Hela cells results of this study and previous work, a classification model to predict the anti-proliferative activity of isoxazole and pyrazole derivatives was developed. Random Forest modeling was used in view of the development of an accurate and reliable model that was subsequently validated. A virtual screening study was then proposed for the design of novel active derivatives. Compounds 9 and 11 demonstrated significant cytostatic activity; the fused isoxazole derivative 18 and the virtually proposed compound 2v, were proved at least 10 times more potent as compared to compound 9, with IC50 values near and below 1 µM. In conclusion, a new series of isoxazoles was exploited with some of them exhibiting promising cytostatic activities. Further studies on the substitution pattern of the isoxazole core can potentially provide compounds with cytostatic action at the nM scale. In this direction the in silico approach described herein can also be used to screen existing databases to identify derivatives with anticipated activity.