Synthesis, and docking studies of phenylpyrimidine-carboxamide derivatives bearing 1H-pyrrolo[2,3-b]pyridine moiety as c-Met inhibitors

Exploring the Potential of Pyridine Carboxylic Acid Isomers to Discover New Enzyme Inhibitors

Pyridine carboxylic acid isomers - picolinic acid, nicotinic acid, and isonicotinic acid - have historically resulted in a plethora of drugs against tuberculosis, cancer, diabetes, Alzheimer's, angina, dementia, depression, allergy, respiratory acidosis, psoriasis, acne, hypertension, hyperlipidemia, HIV/AIDS (specifically HIV-1), among others. Despite the large number of therapeutic agents derived from these isomers, the research involving these scaffolds is still exceptionally active. The current surge in enzyme inhibitory activities by the compounds derived from them has further created space for the discovery of new drug candidates. This review focuses on the medicinal relevance of these isomers by analyzing structure-activity relationships (SARs) and highlighting emerging trends from patents filed over the last decade. Notably, pharmaceutical giants like Bayer, Bristol-Myers Squibb, Novartis, Curis, and Aurigene have developed enzyme inhibitors based on these scaffolds with nanomolar potency. The role of these isomers in the development of antiviral agents, including protease inhibitors, is also discussed. Overall, this review brings to the readers, a pragmatic opportunity to comprehend the recent literature, highlighting the scaffolds' importance in the design of new enzyme inhibitors. Furthermore, it discusses the structure-activity relationship of pyridine carboxylic acid-derived compounds and highlights the current patenting trends in medicinal chemistry.

4,6-Disubstituted pyrimidine-based microtubule affinity-regulating kinase 4 (MARK4) inhibitors: synthesis, characterization, in-vitro activity and in-silico studies

Introduction

Alzheimer's disease (AD) is a neurodegenerative disorder that significantly impacts the cognitive function and memory of a person. Despite the significant research efforts, the ability to completely prevent or effectively treat AD and its related dementias remains limited. Protein kinases are integral to AD pathology and represent promising targets for therapeutic intervention.

Methods

A series of pyrimidine-based compounds 4-(4-(arylsulfonyl)piperazin-1-yl)-6-(thiophen-3-yl)pyrimidine derivatives (8-14) were synthesized and characterised. ATPase inhibition was carried out against the MARK4 enzyme. Molecular docking and molecular dynamics (MD) simulation at 500 ns was carried out against MARK4 (PDB: 5ES1). The drug-likeness feature and toxicity of the molecules were evaluated using QikProp and other tools.

Results

Compounds were synthesized following a multi-step approach and characterized using multi-nuclear magnetic resonance (1H/13C-NMR) and mass spectrometry. ATPase inhibition assay of the compounds against MARK4 showed an IC50 value in the micromolar (μM) range. The results of the docking studies were consistent with the in-vitro experiments and identified (9) and (14) as the candidates with the highest affinity towards MARK4. MD simulation further supported these results, showing that the binding of ligands stabilises the target protein.

Conclusion

Using experimental and theoretical approaches, we demonstrated that the reported class of pyrimidine derivatives are an excellent starting point for developing the next-generation anti-AD drugs.

Design, synthesis, and biological evaluation of new biaryl derivatives of cycloalkyl diacetamide bearing chalcone moiety as type II c-MET kinase inhibitors

Many human cancers have been associated with the deregulation of the mesenchymal-epithelial transition factor tyrosine kinase (MET) receptor, a promising drug target for anticancer drug discovery. Herein, we report the discovery of a novel structure of potent chalcone-based derivatives type II c-Met inhibitors which are comparable to Foretinib (IC50 = 14 nM) as a potent reference drug. Based on our design strategy, we also expected an anti-tubulin activity for the compounds. However, the weak inhibitory effects on microtubules were confirmed by cell cycle analyses implicated that the observed cytotoxicity against HeLa cells probably was not derived from tubulin inhibition. Compounds 14q and 14k with IC50 values of 24 nM and 45 nM, respectively, demonstrated favorable inhibition of MET kinase activity, and desirable bonding interactions in the ligand-MET enzyme complex stability in molecular docking studies.

Pyrrole-containing hybrids as potential anticancer agents: An insight into current developments and structure-activity relationships

Cancer poses a significant threat to human health. Therefore, it is urgent to develop potent anti-cancer drugs with excellent inhibitory activity and no toxic side effects. Pyrrole and its derivatives are privileged heterocyclic compounds with significant diverse pharmacological effects. These compounds can target various aspects of cancer cells and have been applied in clinical settings or are undergoing clinical trials. As a result, pyrrole has emerged as a promising drug scaffold and has been further probed to get novel entities for the treatment of cancer. This article reviews recent research progress on anti-cancer drugs containing pyrrole. It focuses on the mechanism of action, biological activity, and structure-activity relationships of pyrrole derivatives, aiming to assist in designing and synthesizing innovative pyrrole-based anti-cancer compounds.

Anti-proliferative, Morphological and Molecular Docking Studies of New Thiophene Derivatives and their Strategy in Ionic Liquids Immobilized Reactions

BACKGROUND

A number of research were conducted on the pyran and thiophene derivatives, which were attributed to have a wide range of biological activities, including anti-plasmodial, as well as acting as caspase, hepatitis C and cancer inhibitors.

OBJECTIVE

The multicomponent reactions of the 5-acetyl-2-amino-4-(phenylamino)-thiophene-3-carbonitrile produced biologically active target molecules like pyran and their fused derivatives. Comparison between regular catalytic multi-component reactions and solvent-free ionic liquids immobilized multicomponent was studied.

METHODS

The multicomponent reactions in this work were carried out not only under the reflux conditions using triethylamine as a catalyst but also in solvent-free ionic liquids immobilized magnetic nanoparticles (MNPs) catalysts.

RESULTS

Through this work, thirty-one new compounds were synthesized and characterized and were evaluated toward the six cancer cell lines, namely A549, HT-29, MKN-45, U87MG, and SMMC-7721 and H460. The most active compounds were further screened toward seventeen cancer cell lines classified according to the disease. In addition, the effect of compound 11e on the A549 cell line was selected to make further morphological changes in the cell line. The Molecular docking studies of 11e and 11f were carried and promising results were obtained.

CONCLUSION

The synthesis of heterocyclic compounds derived from thiophene derivatives has been receiving significant attention. After a detailed optimizing study, it has been found that the solvent-free ionic liquids immobilized multi-component syntheses afforded a high yield of compounds, opening a greener procedure for this synthetically relevant transformation. Many of the synthesized compounds can be considered anticancer agents, enhancing further studies.

Metal- and Solvent-Free Synthesis of Substituted Pyrimidines via an NH4I-Promoted Three-Component Tandem Reaction

A facile and practical approach for the preparation of substituted pyrimidines from ketones, NH4OAc, and N,N-dimethylformamide dimethyl acetal has been described. This NH4I-promoted three-component tandem reaction affords a broad range of substituted pyrimidines in acceptable yields under metal- and solvent-free conditions. The present methodology features the advantages of simple and easily available starting materials, metal- and solvent-free conditions, a broad substrate scope with good functional group tolerance, and gram-scale synthesis.

Exploring marine-derived compounds for MET signalling pathway inhibition in cancer: integrating virtual screening, ADME profiling and molecular dynamics investigations

The MET signalling pathway regulates fundamental cellular processes such as growth, division, and survival. While essential for normal cell function, dysregulation of this pathway can contribute to cancer by triggering uncontrolled proliferation and metastasis. Targeting MET activity holds promise as an effective strategy for cancer therapy. Among potential sources of anti-cancer agents, marine organisms have gained attention. In this study, we screened 47,450 natural compounds derived from marine sources within the CMNPD database against the Met crystal structure. By employing HTVS, SP, and XP docking modes, we identified three compounds (CMNPD17595, CMNPD14026, and CMNPD19696) that outperformed a reference molecule in binding affinity to the Met structure. These compounds demonstrated desirable ADME properties. Molecular Dynamics (MD) simulations for 200 ns confirmed the stability of their interactions with Met. Our findings highlight CMNPD17595, CMNPD14026, and CMNPD19696 as potential inhibitors against Met-dependent cancers. Additionally, these compounds offer new avenues for drug development, leveraging their inhibitory effects on Met to combat carcinogenesis.

Recent progress on vascular endothelial growth factor receptor inhibitors with dual targeting capabilities for tumor therapy

Vascular endothelial growth factor receptors (VEGFRs) are a family of receptor protein tyrosine kinases that play an important role in the regulation of tumor-induced angiogenesis. Currently, VEGFR inhibitors have been widely used in the treatment of various tumors. However, current VEGFR inhibitors are limited to a certain extent due to limited clinical efficacy and potential toxicity, which hinder their clinical application. Thus, the development of new strategies to improve the clinical outcomes and minimize the toxic effects of VEGFR inhibitors is required. Given the synergistic effect of VEGFR and other therapies in tumor development and progression, VEGFR dual-target inhibitors are becoming an attractive approach due to their favorable pharmacodynamics, low toxicity, and anti-resistant effects. This perspective provides an overview of the development of VEGFR dual-target inhibitors from multiple aspects, including rational target combinations, drug discovery strategies, structure–activity relationships and future directions.

Fused pyrrolo-pyridines and pyrrolo-(iso)quinoline as anticancer agents

This work emphasizes the synthesis strategies and antiproliferative related properties of fused pyrrolo-pyridine (including indolizine and azaindoles) and pyrrolo-(iso)quinoline derivatives recently reported in literature.

Design, Synthesis, and Biological Evaluation of Benzo[cd]indol-2(1H)-ones Derivatives as a Lysosome-Targeted Anti-metastatic Agent

Lysosomes have become a hot topic in tumor therapy; targeting the lysosome is therefore a promising strategy in cancer therapy. Based on our previous lysosome-targeted bio-imaging agent, homospermine-benzo[cd]indol-2(1H)-one conjugate (HBC), we further developed three novel series of polyamine- benzo[cd]indol-2(1H)-one conjugates. Among them, compound 15f showed potent inhibitory activity in hepatocellular carcinoma migration both in vitro and in vivo. Our study results showed that compound 15f entered the cancer cells via the polyamine transporter localized in the lysosomes and caused autophagy and apoptosis. The mechanism of action revealed that the crosstalk between autophagy and apoptosis induced by 15f was mutually reinforcing patterns. Besides, 15f also targeted lysosomes and exhibited stronger green fluorescence than HBC, which indicated its potential as an imaging agent. To summarize, compound 15f could be used as a valuable dual-functional lead compound for future development against liver-cancer metastasis and lysosome imaging.

Spectroscopic, quantum chemical and molecular docking studies on 1-amino-5-chloroanthraquinone: A targeted drug therapy for thyroid cancer

The DFT studies of the 1-Amino-5-chloro-anthraquinone (ACAQ) molecule have been carried out with extensive and accurate investigations of detailed vibrational and spectroscopic investigations and validated by experimentally. The optimized molecular structure and harmonic resonance frequencies were computed based on DFT/B3LYP method with 6-311G++(d,p) basis set using the Gaussian 09 program. The experimental and calculated vibrational wavenumbers were assigned on the basis of PED calculations using VEDA 4.0 program. The ¹³C NMR isotropic chemical shifts of the molecule were calculated using Gauge-Invariant-Atomic Orbital (GIAO) method in DMSO solution and compared with the experimental data. The absorption spectrum of the molecule was computed in liquid phase (ethanol), which exhibits л to л* electronic transition and compared with observed UV-Vis spectrum. Frontier molecular orbitals analysis shows the molecular reactivity and kinetic stability of the molecule. The Mulliken atomic charge distribution and molecular electrostatic potential surface analysis of the molecule validate the reactive site of the molecule. The natural bond orbital analysis proves the bioactivity of the molecule. Molecular docking analysis indicate that ACAQ molecule inhibits the action of c-Met Kinase protein, which is associated with the thyroid cancer. Hence, the present study pave the way for the development of novel drugs in the treatment of thyroid cancer.

Synthesis and Anti-Proliferative Evaluations of New Heterocyclic Derivatives Using 5,6,8,9-Tetrahydropyrazolo[5,1-b]quinazolin-7(3H)-one Derivatives Derived from Cyclohexa-1,4-dione

BACKGROUND

Recentlty, pyrazoloquinazoline derivatives acquired a special attention due to their wide range of pharmacological activities, especially therapeutic. Through the market, it was found that many pharmacological drugs containing the quinazoline nucleus were known.

OBJECTIVE

The aim of this work is to synthesize target molecules possessing not only anti-tumor activities but also kinase inhibitors. The target molecules were obtained through the synthesis of a series of 5,6,8,9- tetrahydropyrazolo[5,1-b]quinazolin-7(3H)-one derivatives 4a-i using the multi-component reactions of cyclohexane- 1,4-dione (1), the 5-amino-4-(2-arylhydrazono)-4H-pyrazol-3-ol derivatives 2a-c, the aromatic aldehydes 3a-c, respectively. The synthesized compounds were evaluated against c-Met kinase, PC-3 cell line, and different kinds of cancer cell lines together with normal cell line, tyrosine kinases, and Pim-1 kinase.

METHODS

Multi-component reactions were adopted using compound 1 to get different 5,6,8,9- tetrahydropyrazolo[5,1-b]quinazolin-7(3H)-one derivatives which underwent further heterocyclization reactions. The c-Met kinase activity of all compounds was evaluated using Homogeneous Time-Resolved Fluorescence (HTRF) assay, taking foretinib as the positive control. The anti-proliferative activity of all target compounds against the human prostatic cancer PC-3 cell line was measured using MTT assay using SGI-1776 as the reference drug. All the synthesized compounds were assessed for inhibitory activities against A549 (non-small cell lung cancer), H460 (human lung cancer), HT-29 (human colon cancer), and MKN-45 (human gastric cancer) cancer cell lines together with foretinib as the positive control by an MTT assay.

RESULTS

Antiproliferative evaluations and c-Met kinase, Pim-1 kinase inhibitions were performed for the synthesized compounds, where the varieties of substituents through the aryl ring and the thiophene moiety afforded compounds with high activities.

CONCLUSION

The compounds with high antiproliferative activity were tested towards c-Met and the results showed that compounds 4e, 4f, 4g, 4i, 6i, 6k, 6l, 8f, 8i, 10d, 10e, 10f, 10h, 12e, 12f, 12g, 12h, 12i, 14f, 14g, 14h, and 14i were the most potent compounds. A further selection of compounds for the Pim-1 kinase inhibition activity showed that compounds 4f, 6i, 6l, 8h, 8i, 8g, 10d, 12i, and 14f were the most active compounds to inhibit Pim-1.

New Approaches for the Synthesis of Heterocyclic Compounds Corporating Benzo[d]imidazole as Anticancer Agents, Tyrosine, Pim-1 Kinases Inhibitions and their PAINS Evaluations

BACKGROUND

Benzo[d]imidazoles are highly biologically active, in addition, they are considered as a class of heterocyclic compounds with many pharmaceutical applications.

OBJECTIVE

We are aiming in this work to synthesize target molecules that possess not only anti-tumor activities but also kinase inhibitors. The target molecules were obtained starting from the benzo[d]imidazole derivatives followed by their heterocyclization reactions to produce anticancer target molecules.

METHODS

The 1-(1H-benzo[d]imidazol-2-yl)propan-2-one (3) and the ethyl 2-(1H-benzo[d]imidazol-2- yl)acetate (16) were used as the key starting material which reacted with salicylaldehyde to give the corresponding benzo[4,5]imidazo[1,2-a]quinoline derivatives. On the other hand, both of them were reacted with different reagents to give thiophene, pyran and benzo[4,5]imidazo[1,2-c]pyrimidine derivatives. The synthesized compounds were evaluated against the six cancer cell lines A549, HT-29, MKN-45, U87MG, SMMC-7721, and H460 together with inhibitions toward tyrosine kinases, c-Met kinase and prostate cancer cell line PC-3 using the standard MTT assay in vitro, with foretinib as the positive control.

RESULTS

Most of the synthesized compounds exhibited high inhibitions toward the tested cancer cell lines. In addition, tyrosine and Pim-1 kinases inhibitions were performed for the most active compounds where the variation of substituent through the aryl ring and heterocyclic ring afforded compounds with high activities. Our analysis showed that there is a strong correlation between the structure of the compound and the substituents of target molecules.

CONCLUSION

Our present research proved that the synthesized heterocyclic compounds with varieties of substituents have a strong impact on the activity of compounds. The evaluations through different cell lines and tyrosine kinases indicated that the compounds were the excellent candidates as anticancer agents. This could encourage doing further research within this field for the building of compounds with high inhibitions.

Synthesis of Tetrahydrobenzo[b]thiophene-3-carbohydrazide Derivatives as Potential Anti-cancer Agents and Pim-1 Kinase Inhibitors

BACKGROUND

Tetrahydrobenzo[b]thiophene derivatives are well known to be biologically active compounds and many of them occupy a wide range of anticancer agent drugs.

OBJECTIVE

One of the main aim of this work was to synthesize target molecules not only possessing anti-tumor activities but also kinase inhibitors. To achieve this goal, our strategy was to synthesize a series of 4,5,6,7- tetrahydrobenzo[b]thiophene-3-carbohydrazide derivatives using cyclohexan-1,4-dione and cyanoacetylhydrazine to give the 2-amino-6-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbohydrazide (3) as the key starting material for many heterocyclization reactions.

METHODS

Compound 3 was reacted with some aryldiazonium salts and the products were cyclised when reacted with either malononitrile or ethyl cyanoacetate. Thiazole derivatives were also obtained through the reaction of compound 3 with phenylisothiocyanate followed by heterocyclization with α-halocarbonyl derivatives. Pyrazole, triazole and pyran derivatives were also obtained.

RESULTS

The compounds obtained in this work were evaluated for their in-vitro cytotoxic activity against c-Met kinase, and the six typical cancer cell lines (A549, H460, HT-29, MKN-45, U87MG, and SMMC-7721). The results of anti-proliferative evaluations and c-Met kinase, Pim-1 kinse inhibitions revealed that some compounds showed high activities.

CONCLUSION

The most promising compounds 5b, 5c, 7c, 7d, 11b, 14a, 16b, 18b, 19, 21a, 23c, 23d and 23i against c-Met kinase were further investigated against the five tyrosin kinases (c-Kit, Flt-3, VEGFR-2, EGFR, and PDGFR). Compounds 5b, 5c, 7d, 7e, 11b, 11c, 16c, 16d, 18c, 19, 23e, 23k and 23m were selected to examine their Pim-1 kinase inhibitions activity where compounds 7d, 7e, 11b, 11c, 16d, 18c and 23e showed high activities. All of the synthesized compounds have no impaired effect toward the VERO normal cell line.

Discovery of Triazolo-pyridazine/-pyrimidine Derivatives Bearing Aromatic (Heterocycle)-Coupled Azole Units as Class II c-Met Inhibitors

Two series of novel triazolo-pyridazine/-pyrimidine derivatives were designed, synthesized, and evaluated for their inhibitory activity against c-Met kinase, as well as three c-Met overexpressed cancer cell lines (A549, MCF-7, and HeLa) and one normal human hepatocytes cell line LO2 in vitro. The pharmacological data indicated that most of the tested compounds showed moderate cytotoxicity, and the most promising compound 12e exhibited significant cytotoxicity against A549, MCF-7, and HeLa cell lines with IC₅₀ values of 1.06 ± 0.16, 1.23 ± 0.18, and 2.73 ± 0.33 μM, respectively. Moreover, the inhibitory activity of compound 12e against c-Met kinase (IC₅₀ = 0.090 μM) was equal to that of Foretinib (IC₅₀ = 0.019 μM). The result of the acridine orange (AO) single staining test demonstrated that compound 12e could remarkably induce apoptosis of A549 cells. The results of apoptosis and cycle distribution of cells showed that compound 12e could induce late apoptosis of A549 cells and stimulate A549 cells arresting in the G0/G1 phase. Structure-activity relationships (SARs), pharmacological results, and docking studies indicated that the introduction of 5-methylthiazole fragment to the five-atom moiety was beneficial for the activity. So far, the existing data indicated that compound 12e may become a potential class II c-Met inhibitor.

Synthesis and Biological Evaluation of Novel 4,5,6,7-Tetrahydrobenzo[D]-Thiazol-2- Yl Derivatives Derived from Dimedone with Anti-Tumor, C-Met, Tyrosine Kinase and Pim-1 Inhibitions

BACKGROUND

Dimedone and thiazole moieties are privileged scaffolds (acting as primary pharmacophores) in many compounds that are useful to treat several diseases, mainly tropical infectious diseases. Thiazole derivatives are a very important class of compounds due to their wide range of pharmaceutical and therapeutic activities. On the other hand, dimedone is used to synthesize many therapeutically active compounds. Therefore, the combination of both moieties through a single molecule to produce heterocyclic compounds will produce excellent anticancer agents.

OBJECTIVE

The present work reports the synthesis of 47 new substances belonging to two classes of compounds: Dimedone and thiazoles, with the purpose of developing new drugs that present high specificity for tumor cells and low toxicity to the organism. To achieve this goal, our strategy was to synthesize a series of 4,5,6,7-tetrahydrobenzo[d]-thiazol-2-yl derivatives using the reaction of the 2-bromodimedone with cyanothioacetamide.

METHODS

The reaction of 2-bromodimedone with cyanothioacetamide gave the 4,5,6,7-tetrahydrobenzo[d]- thiazol-2-yl derivative 4. The reactivity of compound 4 towards some chemical reagents was observed to produce different heterocyclic derivatives.

RESULTS

A cytotoxic screening was performed to evaluate the performance of the new derivatives in six tumor cell lines. Thirteen compounds were shown to be promising toward the tumor cell lines which were further evaluated toward five tyrosine kinases.

CONCLUSION

The results of antitumor screening showed that many of the tested compounds were of high inhibition towards the tested cell lines. Compounds 6c, 8c, 11b, 11d, 13b, 14b, 15c, 15g, 21b, 21c, 20d and 21d were the most potent compounds toward c-Met kinase and PC-3 cell line. The most promising compounds 6c, 8c, 11b, 11d, 13b, 14b, 15c, 15g, 20c, 20d, 21b, 21c and 21d were further investigated against tyrosine kinase (c-Kit, Flt-3, VEGFR-2, EGFR, and PDGFR). Compounds 6c, 11b, 11d, 14b, 15c, and 20d were selected to examine their Pim-1 kinase inhibition activity the results revealed that compounds 11b, 11d and 15c had high activities.

Uses of cyclohexane-1,3-dione for the synthesis of 1,2,4-triazine derivatives as anti-proliferative agents and tyrosine kinases inhibitors

Tetrahydrobenzo[b]thiophene derivatives were well known to be biologically active compounds and many of them occupy a wide range as anticancer agent drugs. One of our main aim of this work was to synthesize target molecules not only possess anti-tumor activities but also kinase inhibitors. To achieve this goal, our strategy was to synthesize a series of novel 1,2,4-triazines as efficient anticancer drugs with low cytotoxicity and good bioavailability properties using cyclohexane-1,3-dione and 3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophene-2-diazonium chloride to give the 2-(2-(2,6-dioxocyclohexylidene)hydrazinyl)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile (3) as the key starting material for many heterocyclization reactions. Compound 3 was reacted with phenylisothiocyanate to give the tetrahydrobenzo[e][1,2,4]triazine derivative 5 which reacted with hydrazines to give dihydrazone derivatives. In addition, it underwent multi-component reactions with aromatic aldehydes and either malononitrile or ethyl cyanoacetate in the presence of triethylamine or ammonium acetate to produce fused pyran and fused pyridine derivatives, respectively. Compounds obtained in this work were evaluated for their c-Met kinase inhibitory potency as well as in-vitro cytotoxic activity against the six typical cancer cell lines (A549, H460, HT-29, MKN-45, U87MG, and SMMC-7721). Molecular modeling studies were carried out for the most active compounds 5, 7a, 7b, 10c, 10e, 11c and 11f using Molecular Operating Environment (MOE) software. It was found that all the tested compounds displayed potent c-Met enzymatic activity with IC₅₀ values ranging from 0.24 to 9.36 nM. Ten of them (5, 7a, 7b, 10c, 10e, 10f, 11b, 11c, 11d and 11f) exhibited higher potency with IC₅₀ values less than 1.00 nM compared with foretinib (IC₅₀ = 1.16 nM). Also those compounds possessed moderate to strong cytotoxicity against the six tested cancer cell lines in the single-digit µM range. The synthesized compounds 5, 7a, 7b, 10c, 10e, 11c and 11f were fit on the active site of c-Met kinase, with almost the same binding pattern as foretinib and higher binding energy scores (from -16.38 to -18.21 kcal/mol) compared to foretinib (-16.37 kcal/mol). A series of novel 1,2,4-triazines were synthesized and displayed potent bioactivities, indicating that these compounds could be considered as a new lead for more investigation in the future.

Discovery of [1,2,4]triazolo[4,3-a]pyrazine derivatives bearing a 4-oxo-pyridazinone moiety as potential c-Met kinase inhibitors

We disclosed the preparation and biological evaluation of a series of [1,2,4]triazolo[4,3-a]pyrazine derivatives bearing 4-oxo-pyridazinone moieties, which demonstrated potent inhibition of c-Met kinase, culminating in the discovery of 22i.

Synthesis, and anti-proliferative, Pim-1 kinase inhibitors and molecular docking of thiophenes derived from estrone

Heterocyclization of steroids were reported to give biologically active products where ring D modification occured. Estrone (1) was used as a template to develop new heterocyclic compounds. Ring D modification of 1 through its reaction with cyanoacetylhydrazine and elemental sulfur gave the thiophene derivative 3. The latter compound reacted with acetophenone derivatives 4a-c to give the hydrazide-hydrazone derivatives 5a-c, respectively. In addition, compound 3 formed thiazole derivatives through its first reaction with phenylisothiocyanate to give the thiourea derivative 9 followed by the reaction of the later with α-halocarbonyl compounds. In the present work a series of novel estrone derivatives were designed, synthesized and evaluated for their in vitro biological activities against c-Met kinase, and six typical cancer cell lines (A549, H460, HT-29, MKN-45, U87MG and SMMC-7721). The most promising compounds 5b, 5c, 11a, 13c, 15b, 15c, 15d, 17a and 17b were further investigated against the five tyrosine kinases c-Kit, Flt-3, VEGFR-2, EGFR, and PDGFR. Compounds 5b, 15d, 17a and 17b were selected to examine their Pim-1 kinase inhibition activity where compounds 15d and 17b showed high activities. Molecular docking of some of the most potent compounds was demonstrated.

Synthesis and bioevaluation and doking study of 1H-pyrrolo[2,3-b]pyridine derivatives bearing aromatic hydrazone moiety as c-Met inhibitors

Two series of aromatic hydrazone derivatives bearing 1H-pyrrolo[2,3-b]pyridine moiety (7a-r, 8a-i, 12a-b, 13a-c, 16a-d and 17a-e) were designed, synthesized and evaluated for the IC₅₀ values against four cancer cell lines (A549, HepG2, MCF-7and PC-3). Two selected compounds (7c and 17e) were further evaluated for the activity against c-Met, Flt-3, VEGFR-2 and EGFR kinases. The data indicated that targets compounds were selective for c-Met kinase. And the most promising compound 7c was further studied in terms of dose-dependent, time-dependent and cell apoptosis. Most of the compounds showed excellent cytotoxicity activity, especially the most promising compound 7c with the IC₅₀ values of 0.82 ± 0.08 μM, 1.00 ± 0.11 μM, 0.93 ± 0.28 μM and 0.92 ± 0.17 μM against A549, HepG2, MCF-7 and PC-3 cell lines and 0.506 μM against c-Met kinase. Structure-activity relationships (SARs) and docking studies indicated that the activities of the phenyl hydrazone derivatives (7a-r and 8a-i) were superior to that of the heterocyclic hydrazone series (12a-b, 13a-c, 16a-d and 17a-e). What's more, the further studies indicated that the target compounds can induce apoptosis of A549 cells and arrest efficiently the cell cycle progression in G2/M phase of A549 cells.

Erastin-Like Anti-Warburg Agents Prevent Mitochondrial Depolarization Induced by Free Tubulin and Decrease Lactate Formation in Cancer Cells

In Warburg metabolism, suppression of mitochondrial metabolism contributes to a low cytosolic ATP/ADP ratio favoring enhanced aerobic glycolysis. Flux of metabolites across the mitochondrial outer membrane occurs through voltage-dependent anion channels (VDAC). In cancer cells, free dimeric tubulin induces VDAC closure and dynamically regulates mitochondrial membrane potential (ΔΨ). Erastin, a small molecule that binds to VDAC, antagonizes the inhibitory effect of tubulin on VDAC and hyperpolarizes mitochondria in intact cells. Here, our aim was to identify novel compounds from the ChemBridge DIVERSet library that block the inhibitory effect of tubulin on ΔΨ using cell-based screening. HCC4006 cells were treated with nocodazole (NCZ) to increase free tubulin and decrease ΔΨ in the presence or absence of library compounds. Tetramethylrhodamine methylester (TMRM) fluorescence was assessed by high-content imaging to determine changes in ΔΨ. Compounds were considered positive if ΔΨ increased in the presence of NCZ. Using confocal microscopy, we identified and validated six lead molecules that antagonized the depolarizing effect of NCZ. Lead compounds and erastin did not promote microtubule stabilization, so changes in ΔΨ were independent of tubulin dynamics. The most potent lead compound also decreased lactate formation. These novel small molecules represent a potential new class of anti-Warburg drugs.

Synthesis and Biological Evaluation of Novel 8-Morpholinoimidazo[1,2-a]pyrazine Derivatives Bearing Phenylpyridine/Phenylpyrimidine-Carboxamides

Herein we designed and synthesized three series of novel 8-morpholinoimidazo[1,2-a]pyrazine derivatives bearing phenylpyridine/phenylpyrimidine-carboxamides (compounds 12a–g, 13a–g and 14a–g). All the compounds were evaluated for their IC₅₀ values against three cancer cell lines (A549, PC-3 and MCF-7). Most of the target compounds exhibited moderate cytotoxicity against the three cancer cell lines. Two selected compounds 14b, 14c were further tested for their activity against PI3Kα kinase, and the results indicated that compound 14c showed inhibitory activity against PI3Kα kinase with an IC₅₀ value of 1.25 μM. Structure-activity relationships (SARs) and pharmacological results indicated that the replacement of the thiopyranopyrimidine with an imidazopyrazine was beneficial for the activity and the position of aryl group has a significant influence to the activity of these compounds. The compounds 13a–g in which an aryl group substituted at the C-4 position of the pyridine ring were more active than 12a–g substituted at the C-5 position. Moreover, the cytotoxicity of compounds 14a–g bearing phenylpyrimidine-carboxamides was better than that of the compounds 12a–g, 13a–g bearing phenylpyridine-carboxamides. Furthermore, the substituents on the benzene ring also had a significant impact on the cytotoxicity and the pharmacological results showed that electron donating groups were beneficial to the cytotoxicity.

Synthesis and Biological Evaluation of Novel 4-Morpholino-7,8-dihydro-5H-thiopyrano[4,3-d]pyrimidine Derivatives Bearing Phenylpyridine/ Phenylpyrimidine-Carboxamides

Four series of novel 4-morpholino-7,8-dihydro-5H-thiopyrano[4,3-d]pyrimidine derivatives 11a–j, 12a–j, 13a–g and 14a–g bearing phenylpyridine/phenylpyrimidine- carboxamide scaffolds were designed, synthesized and their IC₅₀ values against three cancer cell lines (A549, PC-3 and MCF-7) were evaluated. Eleven of the compounds showed moderate cytotoxicity activity against the cancer cell lines. Structure-activity relationships (SARs) and pharmacological results indicated that the introduction of phenylpyridine-carboxamide scaffold was beneficial for the activity. What’s more, the oxidation of the sulfur atom in thiopyran and various types of substituents on the aryl group have different impacts on different series of compounds. Furthermore, the positions of aryl group substituents have a slight impact on the activity of the phenylpyridine-carboxamide series compounds.

Synthesis, activity and docking studies of phenylpyrimidine-carboxamide Sorafenib derivatives

Two series of Sorafenib derivatives bearing phenylpyrimidine-carboxamide moiety (16a-g and 17a-p) were designed, synthesized and evaluated for the IC₅₀ values against three cancer cell lines (A549, MCF-7 and PC-3). Two selected compounds (17f and 17n) were further evaluated for the activity against VEGFR2/KDR kinase. More than half of the synthesized compounds showed moderate to excellent activity against three cancer cell lines. Compound 17f showed equal activity to Sorafenib against MCF-7 cell line, with the IC₅₀ values of 6.35±0.43μM. Meanwhile, compound 17n revealed more active than Sorafenib against A549 cell line, with the IC₅₀ values of 3.39±0.37μM. Structure-activity relationships (SARs) and docking studies indicated that the second series (17a-p) showed more active than the first series (16a-g). What's more, the introduction of fluoro atom to the phenoxy part played no significant impact on activity. In addition, the presence of electron-donating on aryl group was benefit for the activity.