Pyridine-derived VEGFR-2 inhibitors: Rational design, synthesis, anticancer evaluations, in silico ADMET profile, and molecular docking

New pyridine-based chalcones and pyrazolines with anticancer, antibacterial, and antiplasmodial activities

New pyridine-based chalcones 4a-h and pyrazolines 5a-h (N-acetyl), 6a-h (N-phenyl), and 7a-h (N-4-chlorophenyl) were synthesized and evaluated by the National Cancer Institute (NCI) against 60 different human cancer cell lines. Pyrazolines 6a, 6c-h, and 7a-h satisfied the pre-determined threshold inhibition criteria, obtaining that compounds 6c and 6f exhibited high antiproliferative activity, reaching submicromolar GI50 values from 0.38 to 0.45 μM, respectively. Moreover, compound 7g (4-CH3) exhibited the highest cytostatic activity of these series against different cancer cell lines from leukemia, nonsmall cell lung, colon, ovarian, renal, and prostate cancer, with LC50 values ranging from 5.41 to 8.35 μM, showing better cytotoxic activity than doxorubicin. Furthermore, the compounds were tested for antibacterial and antiplasmodial activities. Chalcone 4c was the most active with minimal inhibitory concentration (MIC) = 2 μg/mL against methicillin-resistant Staphylococcus aureus (MRSA), while the pyrazoline 6h showed a MIC = 8 μg/mL against Neisseria gonorrhoeae. For anti-Plasmodium falciparum activity, the chalcones display higher activity with EC50 values ranging from 10.26 to 10.94 μg/mL. Docking studies were conducted against relevant proteins from P. falciparum, exhibiting the minimum binding energy with plasmepsin II. In vivo toxicity assay in Galleria mellonella suggests that most compounds are low or nontoxic.

Synthesis of novel nicotinic acid derivatives of potential antioxidant and anticancer activity

This study comprises the design and synthesis of novel nicotinic acid-based cytotoxic agents with selective inhibitory efficacy against the vascular endothelial growth factor receptor-2 (VEGFR-2). Screening of novel compounds for cytotoxicity was assessed against 60 human cancer cell lines. The two most active compounds, 5b and 5c, and the reference drugs sorafenib and doxorubicin were investigated against HCT-15, PC-3, and CF-295 cancer cell lines. Compound 5c exhibited the highest cytotoxic potential compared to doxorubicin against the HCT-15 and PC-3 tumor cell lines. Moreover, it exhibited higher cytotoxic potential and selectivity toward the HCT-15 cell panel compared with sorafenib. Compound 5c demonstrated promising VEGFR-2 inhibition (concentration needed to inhibit cell viability by 50%, IC50  = 0.068 μM) and superior VEGFR-2 selectivity over the epidermal growth factor receptor and platelet-derived growth factor receptor-β enzymes. It also reduced the total and phosphorylated VEGFR-2 and induced apoptosis, as evidenced by a 4.3-fold rise in caspase-3 levels. The antioxidant potential of the new compounds was determined via measuring the superoxide dismutase (SOD) levels, among which compound 5c exhibited an SOD level almost comparable to ascorbic acid. These results suggested that compound 5c exhibited dual cytotoxic and antioxidant activities. Docking of 5c into the VEGFR-2 pocket showed a similar binding mode to sorafenib. Moreover, the ADME (absorption, distribution, metabolism, and excretion) profile of 5c outlined drug-likeness. Finally, The density functional theory calculations displayed an increased binding affinity of 5c to the target enzyme.

Five and six membered heterocyclic rings endowed with azobenzene as dual EGFRT790M and VEGFR-2 inhibitors: design, synthesis, in silico ADMET profile, molecular docking, dynamic simulation and anticancer evaluations

Novel azobenzene scaffold-joined heterocyclic isoxazole, pyrazole, triazole, and/or triazine moieties have been developed and synthesized utilizing microwave and traditional methods. Our compounds were tested for growth inhibition of A549, MCF-7, HCT-116, and HepG2 tumors by dual targeting the VEGFR-2 and EGFRT790M enzymes. The suggested compound's manner of binding with EGFRT790M and VEGFR-2 active sites was explored through molecular design and MD modeling. The information from the results of the biological screening and the docking studies was highly correlated. The A549 cell line was the one that responded to the novel compound's effects most effectively. Having IC50 values of 5.15, 6.37, 8.44 and 6.23 μM, respectively, 14 was the most effective derivative on the four A549, MCF-7, HCT116 and HepG2 cancer cells. It had greater activity than erlotinib and slightly inferior activities on the tested cell lines than sorafenib, respectively. The cytotoxicity of the most effective derivatives, 5, 6, 10 and 14, was evaluated against typical VERO cell lines. Having IC50 values ranging from 42.32 to 55.20 μM, the results showed that the investigated drugs have modest toxicity against VERO normal cells. Additionally all derivatives were assessed for their dual VEGFR-2 and EGFRT790M inhibitory effects. Among them, derivatives 14, 5 and 10 were established as the greatest inhibitors of VEGFR-2 at IC50 values of 0.95, 1.25 and 1.50 μM correspondingly. As well, derivatives 14, 6, 5 and 10 could inhibit EGFRT790M activity demonstrating strongest effects with IC50 = 0.25, 0.35, 0.40 and 0.50 μM respectively. Furthermore, the ADMET profile was evaluated for compounds 5, 6, 10 and 14 in contrast to reference drugs sorafenib and erlotinib.

Crystal structure of 4-(naphthalen-2-yl)-2-oxo-6-phenyl-1,2-di-hydro-pyridine-3-carbo-nitrile

The synthesis and crystal structure of the title compound, C22H14N2O, are described. The title compound was synthesized by a three-component one-pot reaction in DMSO involving chalcone, cyano-acetamide and elemental sulfur as catalyst. The compound was characterized by spectroscopic methods and single-crystal X-ray diffraction. The structure consists of inversion-related dimers produced by N-H⋯O hydrogen bonding, which further inter-act through π-π contacts.

In silico, in vitro VEGFR-2 inhibition, and anticancer activity of a 3-(hydrazonomethyl)naphthalene-2-ol derivative

In agreement with the general features of VEGFR-2 inhibitors, a new naphthalene analog (compound 7) has been designed and synthesized. The inhibitory potential of compound 7 was indicated by the proper binding and the perfect energy of -21.10 kcal/mol compared to sorafenib (-21.22) in the molecular docking studies. Next, six MD simulation studies over 100 ns (RMSD, RMSF, SASA, RoG, hydrogen bonding, and distance between the center of mass) confirmed the accurate interaction of compound 7 with the catalytic pocket of VEGFR-2. Similarly, an MM-GBSA established proper binding showing an exact total binding energy of -36.95 ± 3.03 kcal/Mol. Additionally, the MM-GBSA experiment indicated the vital amino acids in the binding process. Types and number of interactions of compound 7 with catalytic pocket of VEGFR-2 were determined through Protein-Ligand Interaction Profiler (PLIP). As a new compound, the DFT was employed to optimize the molecular structure of compound 7. The DFT experiments also verified the interaction features of compound 7 with the VEGFR-2 active site. In silico ADMET experiments revealed the general drug-likeness of compound 7. Fascinatingly, the in vitro examinations were consistent with the in silico experiments as compound 7 inhibited the VEGFR-2 enzyme with an IC50 value of 37 nM. Captivatingly, compound 7 inhibited both MCF-7 and HCT 116 cancer cells exhibiting IC50 values of 10.56 and 7.07 µM exhibiting excellent selectivity indexes of 9.04 and 13.50, respectively.Communicated by Ramaswamy H. Sarma.

Recent advances in nitrogen-containing heterocyclic compounds as receptor tyrosine kinase inhibitors for the treatment of cancer: Biological activity and structural activity relationship

Erratic cell proliferation is the initial symptom of cancer, which can eventually metastasize to other organs. Before cancer becomes metastatic, its spread is triggered by pro-angiogenic factors including vascular endothelial growth factor receptor (VEGFR), epidermal growth factor receptor (EGFR), Platelet-derived growth factor receptor (PDGFR), fibroblast growth factor receptor (FGFR) and Platelet Factor (PF4), all of which are part of receptor tyrosine kinase (RTK) family. Receptor tyrosine kinases (RTKs) are cell-surface proteins and aresignaling enzymes that transfer ATP-phosphate to tyrosine residue substrates. Important biological processes like proliferation, differentiation, motility, and cell-cycle regulation are all possessedby these proteins. Unusual RTK expression is typically associated with cell growth abnormalities, which is linked to tumor acquisition, angiogenesis, and cancer progression. In addition to the already available medications, numerous other heterocyclic are being studied for their potential action against a variety of cancers. In the fight against cancer, in particular, these heterocycles have been used for their dynamic core scaffold and their inherent adaptability. In this review article, we have compiled last five years research work including nitrogen containing heterocycles that have targeted RTK. Herein, the SAR and activity of various compounds containing diverse heterocyclic (pyrimidine, indole, pyridine, pyrazole, benzimidazole, and pyrrole) scaffolds are discussed, and they may prove useful in the future for designing new leads against RTKs. Our focus in this manuscript is to comprehensively review the latest research on the biological activity and structural activity relationship of nitrogen compounds as RTK inhibitors. We believe that this may be an important contribution to the field, as it can help guide future research efforts and facilitate the development of more effective cancer therapies.

Sulfur-Promoted Oxidative Condensation of Chalcones with Unsubstituted Cyanoacetamide in DMSO: Access to 3-Cyanopyrid-2-ones

Elemental sulfur and DABCO were found to be an excellent combination to promote a one-pot cascade of condensation-oxidative cyclization of chalcones and unsubstituted cyanoacetamide in DMSO to provide 3-cyanopyrid-2-ones.

Design, synthesis, in silico studies, and biological evaluation of novel pyrimidine-5-carbonitrile derivatives as potential anti-proliferative agents, VEGFR-2 inhibitors and apoptotic inducers

A novel series of pyrimidine-5-carbonitrile derivatives bearing benzylidene and hydrazone moieties with different linkers (spacers) were designed and synthesized as possible inhibitors of the vascular endothelial growth factor receptor-2 (VEGFR-2). The newly synthesized compounds were evaluated in vitro for their cytotoxic activities against two human cancer cell lines namely colon cancer (HCT-116) and breast cancer (MCF-7) using sorafenib as a standard anticancer drug. Compounds 9d, 11e, 12b, and 12d showed higher cytotoxic activities than sorafenib with IC₅₀ values ranging from 1.14 to 10.33 μM. In particular, compound 11e exhibited excellent activities against HCT-116 and MCF-7 with IC₅₀ values of 1.14 and 1.54 μM, respectively. Moreover, compound 11e exhibited about 47.32-fold cytotoxic activity against normal human fibroblast (WI-38) cells, lower than the cytotoxicity against the cancer cells. Compounds 11e and 12b were the most potent VEGFR-2 inhibitors with IC₅₀ values of 0.61 and 0.53 μM, respectively, compared to sorafenib. Bedsides, compound 11e arrested the HCT-116 cell growth at S and sub-G1 phases, induced a significant increase in the apoptotic cells, and caused remarkable decrease in the levels of TNF-α, IL-6, and caspase-3. Finally, the binding patterns of the target derivatives were investigated through the docking study against the proposed molecular target (VEGFR-2, PDB ID 1YWN). The results of molecular docking studies showed similar binding modes to sorafenib against VEGFR-2. In addition, molecular dynamic simulations revealed the stability of compound 11e in the active site for 100 ns.

Synthesis, Antioxidant and Antiproliferative Evaluation, Molecular Docking and DFT Studies of Some Novel Coumarin and Fused Coumarin Derivatives

N'-[(4-Chloro-2-oxo-2H-chromen-3-yl)methylene]-2-cyanoacetohydrazide (3) was synthesized in excellent yield from the condensation of 4-Chloro-2-oxo-2H-chromene-3-carbaldehyde with cyanoacetohydrazide. Compound 3 was utilized as a building block to synthesize novel coumarin and heterocycle-fused coumarin derivatives. The chemical structures of all the new coumarin compounds were identified by spectral analyses. Some of the new coumarins compounds were screened in human cancer cell lines (HEPG-2, MCF-7, HCT-116 and PC-3) to learn about their cytotoxic effects in addition to the study of their DNA damage and antioxidant activity. Three of these compounds exhibited remarkable antioxidant and anti-proliferative activities. Moreover, they have the capability to protect DNA from damage induced by bleomycin. Molecular docking, DFT and molecular electrostatic potential studies were performed on the compounds in vitro.

Novel VEGFR-2 Kinase Inhibitors as Anticancer Agents: A Review Focusing on SAR and Molecular Docking Studies (2016-2021)

Cancer growth, annexation, and metastatic spread are all aided by the formation of new blood vessels (angiogenesis). The commencement of the VEGF pathway leads to signal transduction that enhances endothelial cell survival, relocation, and divergence from pre-existing vasculature. The ability of solid malignancies to bloom and spread depends critically on their ability to establish their independent blood circulation (tumor angiogenesis). VEGFR is a major receptor tyrosine kinase that regulates angiogenesis, cell growth, and metastasis, diminishing apoptosis, cytoskeletal function, and other biological processes VEGFR has proven to be a remarkable focus for a variety of anticancer medicines in clinical studies. This Review explores the development of anti-VEGF-based antiangiogenic therapies having different scaffolds. This review had focused on SAR and docking studies of previously reported molecules.

New benzoxazole derivatives as potential VEGFR-2 inhibitors and apoptosis inducers: design, synthesis, anti-proliferative evaluation, flowcytometric analysis, and in silico studies

A new series of benzoxazole derivatives were designed and synthesised to have the main essential pharmacophoric features of VEGFR-2 inhibitors. Cytotoxic activities were evaluated for all derivatives against two human cancer cell lines, MCF-7 and HepG2. Also, the effect of the most cytotoxic derivatives on VEGFR-2 protein concentration was assessed by ELISA. Compounds 14o, 14l, and 14b showed the highest activities with VEGFR-2 protein concentrations of 586.3, 636.2, and 705.7 pg/ml, respectively. Additionally, the anti-angiogenic property of compound 14b against human umbilical vascular endothelial cell (HUVEC) was performed using a wound healing migration assay. Compound 14b reduced proliferation and migratory potential of HUVEC cells. Furthermore, compound 14b was subjected to further biological investigations including cell cycle and apoptosis analyses. Compound 14b arrested the HepG2 cell growth at the Pre-G1 phase and induced apoptosis by 16.52%, compared to 0.67% in the control (HepG2) cells. The effect of apoptosis was buttressed by a 4.8-fold increase in caspase-3 level compared to the control cells. Besides, different in silico docking studies were also performed to get better insights into the possible binding mode of the target compounds with VEGFR-2 active sites.

(E)-N-(3-(1-(2-(4-(2,2,2-Trifluoroacetamido)benzoyl)hydrazono)ethyl)phenyl)nicotinamide: A Novel Pyridine Derivative for Inhibiting Vascular Endothelial Growth Factor Receptor-2: Synthesis, Computational, and Anticancer Studies

(E)-N-(3-(1-(2-(4-(2,2,2-Trifluoroacetamido)benzoyl)hydrazono)ethyl)phenyl)nicotinamide (compound 10) was designed as an antiangiogenic VEGFR-2 inhibitor with the essential pharmacophoric structural properties to interact with the catalytic pocket of VEGFR-2. The designed derivative was synthesized, and its structure was confirmed through Ms, elemental, ¹H, and ¹³C spectral data. The potentiality of the designed pyridine derivative to bind with and inhibit the vascular endothelial growth factor receptor-2 (VEGFR-2) enzyme was indicated by molecular docking assessments. In addition, six molecular dynamic (MD) experiments proved its correct binding with VEGFR-2 over 100 ns. Additionally, the molecular mechanics energies, combined with the generalized born and surface area (MM-GBSA) analysis, identified the precise binding with optimum energy. To explore the stability and reactivity of the designed pyridine derivative, density functional theory (DFT) calculations, including electrostatic potential maps and total electron density, were carried out. Additionally, the absorption, distribution, metabolism, excretion, and toxicity (ADMET) analysis demonstrated its general likeness and its safety. The designed compound was synthesized to evaluate its effects against VEGFR-2 protein, cancer, and normal cells. The in vitro results were concordant with the in silico results, because the new pyridine derivative (compound 10) displayed VEGFR-2 inhibition with an IC₅₀ value of 65 nM and displayed potent cytotoxic properties against hepatic (HepG2) and breast (MCF-7) cancer cell lines with IC₅₀ values of 21.00 and 26.10 μM, respectively; additionally, it exhibited high selectivity indices against the normal cell lines (W-38) of 1.55 and 1.25, respectively. The obtained results present compound 10 as a new lead VEGFR-2 inhibitor for further biological investigation and chemical modifications.

Discovery of New VEGFR-2 Inhibitors: Design, Synthesis, Anti-Proliferative Evaluation, Docking, and MD Simulation Studies

Four new nicotinamide-based derivatives were designed as antiangiogenic VEGFR-2 inhibitors. The congeners were synthesized possessing the pharmacophoric essential features to bind correctly with the VEGFR-2 active pocket. All members were evaluated for their cytotoxic and VEGFR-2 inhibitory potentialities. Compound 6 was the most potent showingIC₅₀ values of 9.3 ± 0.02 and 7.8 ± 0.025 µM against HCT-116 and HepG-2 cells, respectively, and IC₅₀ of 60.83 nM regarding VEGFR-2 enzyme inhibition. Compound 6 arrested the growth of HCT-116 cells at the pre-G1 and G2-M phases. Further, it induced both early and late apoptosis. Additionally, compound 6 caused a significant decrease in TNF-α and IL6 by 66.42% and 57.34%, respectively. The considered compounds had similar docking performances to that of sorafenib against the VEGFR-2 (PDB ID: 2OH4). The correct binding of compound 6 with VEGFR-2 was validated using MD simulations, and MM-GPSA calculations.

The Assessment of Anticancer and VEGFR-2 Inhibitory Activities of a New 1H-Indole Derivative: In Silico and In Vitro Approaches

Corresponding to the reported features of anti-VEGFR-2-approved compounds, a new 1H-indole derivative (compound 7) was designed. The inhibitory potential of the designed compound was revealed via a molecular docking study that showed the appropriate binding. Then, MD simulation (six studies) over a period of 100 ns was performed to confirm the precise binding and optimum energy. Additionally, MM-GBSA reaffirmed the perfect binding, exhibiting a total precise energy of −40.38 Kcal/Mol. The MM-GBSA experiments named the essential amino acids in the protein–ligand interaction, employing the binding energy decomposition and revealing the diversity of interactions of compound 7 inside the VEGFR-2 enzyme. As compound 7 is new, DFT experiments were utilized for molecular structure optimization. Additionally, the DFT results validated the coherent interaction of compound 7 with the VEGFR-2 enzyme. A good value of drug-likeness of compound 7 was acknowledged via in silico ADMET studies. Interestingly, the experimental in vitro prohibitory potential of compound 7 was better than that of sorafenib, demonstrating an IC50 value of 25 nM. Notably, the strong inhibitory effects of compound 10 against two cancer cell lines (MCF-7 and HCT 116) were established with IC50 values of 12.93 and 11.52 μM, disclosing high selectivity indexes of 6.7 and 7.5, respectively.

Oxadiazole: A highly versatile scaffold in drug discovery

As a pharmacologically important heterocycle, oxadiazole paved the way to combat the problem associated with the confluence of many commercially available drugs with different pharmacological profiles. The present review focuses on the potential applications of five-membered heterocyclic oxadiazole derivatives, especially 1,2,4-oxadiazole, 1,2,5-oxadiazole, and 1,3,4-oxadiazole, as therapeutic agents. Designing new hybrid molecules containing the oxadiazole moiety is a better solution for the development of new drug molecules. The designed molecules may accumulate a biological profile better than those of the drugs currently available on the market. The present review will guide the way for researchers in the field of medicinal chemistry to design new biologically active molecules based on the oxadiazole nucleus. Antitubercular, antimalarial, anti-inflammatory, anti-HIV, antibacterial, and anticancer activities of various oxadiazoles have been reviewed extensively here.

New quinoxalin-2(1H)-one-derived VEGFR-2 inhibitors: Design, synthesis, in vitro anticancer evaluations, in silico ADMET, and docking studies

More than 70% of cancer patients who are treated with chemotherapeutics do not show a durable response. As part of the global plan seeking new effective chemotherapeutics, here, we report the synthesis and in vitro and computational studies of new lenvatinib and sorafenib analog quinoxalines as vascular endothelial growth factor receptor II (VEGFR-2) tyrosine kinase inhibitors. The central quinolone and pyridine moieties of the Food and Drug Administration-approved anticancer agents lenvatinib and sorafenib were replaced with the versatile quinoxaline scaffold that has been exploited for developing potent cytotoxic agents. With some minor structural optimizations, all the other pharmacophoric features of lenvatinib and sorafenib were maintained. Accordingly, three new sets of quinoxalines were synthesized to evaluate their activity against liver, colorectal, and breast malignancies. The results obtained in the in vitro cytotoxicity evaluation study revealed the superior activity of three derivatives (20, 25, and 29) compared with that of doxorubicin and sorafenib. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiling and docking of 20, 25, and 29 into the VEGFR-2 receptor were also performed. Results of in silico studies showed the potential of the designed compounds to bind effectively with a number of key residues. The obtained in vitro cytotoxic activity and ADMET profiles of compounds 20, 25, and 29 suggested that they should be subjected to further structural optimizations to develop new candidates in cancer treatment protocols.

Antiproliferative evaluations of triazoloquinazolines as classical DNA intercalators: Design, synthesis, ADMET profile, and molecular docking

Novel triazoloquinazolines were designed and synthesized and evaluated as anticancer agents against HepG2 and HCT-116 cells. The biological testing data corresponded well to those of the molecular docking studies. The HCT-116 cell line was most affected due to the actions of our derivatives. Derivative 7_a was the most potent one against both HepG2 and HCT116 cells, with IC₅₀  = 7.98 and 5.57 µM, respectively. This compound showed anticancer activity that was nearly equipotent to that of doxorubicin against HepG2 cells, but higher than that of doxorubicin against HCT116 cells (IC₅₀  = 7.94 and 8.07 µM, respectively). Compounds 8, 7_b , and 6_f showed excellent anticancer activities against both the HCT116 and HepG2 cell lines. The highly active compounds 6_f , 7_a , 7_b , and 8 were evaluated for their DNA-binding activities. Compounds 7_a and 8 showed the highest binding activities. These derivatives potently intercalate in DNA, at IC₅₀ values of 42.90 and 48.13 µM, respectively. Derivatives 6_f and 7_b showed good DNA-binding activities, with IC₅₀ values of 54.24 and 50.56 µM, respectively. Furthermore, in silico calculated ADMET profiles were established for our four highly active derivatives, in comparison to doxorubicin. Our derivatives 6_f , 7_a , 7_b , and 8 showed a very good ADMET profile. Compounds 6_f , 7_a , 7_b , and 8 follow Lipinski's rules, while doxorubicin violates three of these rules.

Design, Molecular Docking, Synthesis, Anticancer and Anti-Hyperglycemic Assessments of Thiazolidine-2,4-diones Bearing Sulfonylthiourea Moieties as Potent VEGFR-2 Inhibitors and PPARγ Agonists

Newly designed thiazolidine-2,4-diones 3–7a–c were synthesized, and their anticancer activities were screened against three cancer lines. They showed potent activities against HepG2 compared to the other HCT116 and MCF-7 tumor cell lines. Compounds 7c and 6c were detected as highly effective derivatives against MCF-7 (IC₅₀ = 7.78 and 8.15 µM), HCT116 (IC₅₀ = 5.77 and 7.11 µM) and HepG2 (IC₅₀ = 8.82 and 8.99 µM). The highly effective derivatives 6a–c and 7a–c were tested against VERO normal cell lines. All derivatives were evaluated for their VEGFR-2 inhibitory actions and demonstrated high to low activities, with IC₅₀ values varying from 0.08 to 0.93 µM. Moreover, derivatives 5a–c, 6a–c and 7a–c were assessed to verify their in vitro binding affinities to PPARγ and insulin-secreting activities. Finally, docking studies were performed to explore their affinities and binding modes toward both VEGFR-2 and PPARγ receptors.

Effect of a Substituent in the Fourth Position on the Optical Properties of 2-Oxonicotinonitriles

Based on six representatives of 2-oxonicotinonitriles, the effect of the nature of the substituent in the fourth position of the pyridine system on the photophysical characteristics was studied. The role of the donor/acceptor nature of the substituent and the solvent nature in the absorbing and fluorescent properties of the compounds was shown.

Topo II inhibition and DNA intercalation by new phthalazine-based derivatives as potent anticancer agents: design, synthesis, anti-proliferative, docking, and in vivo studies

This research presents the design and synthesis of a novel series of phthalazine derivatives as Topo II inhibitors, DNA intercalators, and cytotoxic agents. In vitro testing of the new compounds against HepG-2, MCF-7, and HCT-116 cell lines confirmed their potent cytotoxic activity with low IC₅₀ values. Topo II inhibition and DNA intercalating activities were evaluated for the most cytotoxic members. IC₅₀ values determination demonstrated Topo II inhibitory activities and DNA intercalating affinities of the tested compounds at a micromolar level. Amongst, compound 9d was the most potent member. It inhibited Topo II enzyme at IC₅₀ value of 7.02 ± 0.54 µM with DNA intercalating IC₅₀ of 26.19 ± 1.14 µM. Compound 9d was then subjected to an in vivo antitumor examination. It inhibited tumour proliferation reducing solid tumour volume and mass. Additionally, it restored liver enzymes, proteins, and CBC parameters near-normal, indicating a remarkable amelioration in their functions along with histopathological examinations.

Design, synthesis, anticancer, and docking of some S- and/or N-heterocyclic derivatives as VEGFR-2 inhibitors

Novel heterocyclic derivatives (4-22) were designed, synthesized, and evaluated against hepatocellular carcinoma type (HepG2) and breast cancer (MCF-7) cells, targeting the VEGFR-2 enzyme. Compounds 18, 10, 13, 11, and 14 were found to be the most potent derivatives against both the HepG2 and MCF-7 cancer cell lines, with GI₅₀  = 2.11, 2.54 µM, 3.16, 3.64 µM, 3.24, 6.99 µM, 7.41, 6.49 µM and 8.08, 10.46 µM, respectively. Compounds 18 and 10 showed higher activities against both HepG2 and MCF-7 cells than sorafenib (GI₅₀  = 9.18, 5.47 µM, respectively) and doxorubicin (GI₅₀  = 7.94, 8.07 µM, respectively). Compounds 13, 11, and 14 showed higher activities than sorafenib against HepG2 cancer cells, but lower activities against MCF-7 cells. Compounds 18, 13, and 10 were more potent than sorafenib, inhibiting vascular endothelial growth factor receptor-2 (VEGFR-2) at GI₅₀ values of 0.05, 0.06, and 0.08 µM, respectively. Compound 11 inhibited VEGFR-2 at an IC₅₀ value of 0.10 µM, which is equipotent to sorafenib. Compound 14 inhibited VEGFR-2 at an IC₅₀ value of 0.11 µM, which is nearly equipotent to sorafenib. The tested compounds have more selectivity against cancer cell lines. Compounds 18, 10, 13, 11, and 14 are, respectively, 16.76, 9.24, 6.06, 2.78, and 2.85 times more toxic in HePpG2 cancer cells than in VERO normal cells. Also, compounds 18, 10, 13, 11, and 14 are, respectively, 14.07, 8.02, 2.81, 3.18, and 2.20 times more toxic in MCF-7 than in VERO normal cells. The most active compounds, 10, 13, and 18, showed a good ADMET (absorption, distribution, metabolism, excretion, and toxicity) profile.

Design, synthesis, docking, and anticancer evaluations of phthalazines as VEGFR-2 inhibitors

Twenty new N-substituted-4-phenylphthalazin-1-amine derivatives were designed, synthesized, and evaluated for their anticancer activities against HepG2, HCT-116, and MCF-7 cells as VEGFR-2 inhibitors. HCT-116 was the most sensitive cell line to the influence of the new derivatives. In particular, compound 7f was found to be the most potent derivative among all the tested compounds against the three cancer cell lines, with 50% inhibition concentration, IC₅₀  = 3.97, 4.83, and 4.58 µM, respectively, which is more potent than both sorafenib (IC₅₀  = 9.18, 5.47, and 7.26 µM, respectively) and doxorubicin (IC₅₀  = 7.94, 8.07, and 6.75 µM, respectively). Fifteen of the synthesized derivatives were selected to evaluate their inhibitory activities against VEGFR-2. Compound 7f was found to be the most potent derivative that inhibited VEGFR-2 at an IC₅₀ value of 0.08 µM, which is more potent than sorafenib (IC₅₀  = 0.10 µM). Compound 8c inhibited VEGFR-2 at an IC₅₀ value of 0.10 µM, which is equipotent to sorafenib. Moreover, compound 7a showed very good activity with IC₅₀ values of 0.11 µM, which is nearly equipotent to sorafenib. In addition, compounds 7d, 7c, and 7g possessed very good VEGFR-2-inhibitory activity, with IC₅₀ values of 0.14, 0.17, and 0.23 µM, respectively.

Recent developments in mitogen activated protein kinase inhibitors as potential anticancer agents

The mitogen activated protein kinase (MAPK) belongs to group of kinase that links the extracellular stimuli to intracellular response. The MAPK signalling pathway (RAS-RAF-MEK-ERK) involved in different pathological conditions like cancer, caused due to genetic or any other factor such as physical or environmental. Many studies have been conducted on the pathological view of MAPK cascade and its associated element like RAS, RAF, MEK, ERK or its isoforms, and still the research is going on particularly with respect to its activation, regulation and inhibition. The MAPK signalling pathway has become the area of research to identify new target for the management of cancer. A number of heterocyclics are key to fight with the cancer associated with these enzymes thus give some hope in the management of cancer by inhibiting MAPK cascade. In the present article, we have focussed on MAPK signalling pathway and role of different heterocyclic scaffolds bearing nitrogen, sulphur and oxygen and about their potential to block MAPK signalling pathway. The heterocyclics are gaining importance due to high potency and selectivity with less off-target effects against different targets involved in the MAPK signalling pathway. We have tried to cover recent advancements in the MAPK signalling pathway inhibitors with an aim to get better understanding of the mechanism of action of the compounds. Several compounds in the preclinical and clinical studies have been thoroughly dealt with. In addition to the synthetic compounds, a significant number of natural products containing heterocyclic moieties as MAPK signalling pathway inhibitors have been put together. The structure activity relationship along with docking studies have been discussed to apprehend the mechanistic studies of various compounds that will ultimately help to design and develop more MAPK signalling pathway inhibitors.

Metal-free domino amination-Knoevenagel condensation approach to access new coumarins as potent nanomolar inhibitors of VEGFR-2 and EGFR

A metal-free, atom-economy and simple work-up domino amination-Knoevenagel condensation approach to construct new coumarin analogous (4a-f and 8a-e) was described. Further, new formyl (5a,d-f) and nitro (9a,d-f) coumarin derivatives were synthesized via C-N coupling reaction of various cyclic secondary amines and 4-chloro-3-(formyl-/nitro)coumarins (1a,c), respectively. The confirmed compounds were screened for their in vitro anti-proliferative activity against KB-3-1, A549 and PC3 human cancer cell lines using resazurin cellular-based assay. Among them, coumarin derivatives 4e and 8e displayed the best anti-cervical cancer potency (KB-3-1) with IC₅₀ values of 15.5 ± 3.54 and 21 ± 4.24 μM, respectively. Also, 4e showed the most promising cytotoxicity toward A549 with IC₅₀ value of 12.94 ± 1.51 μM. As well, 9d presented a more significant impact of potency against PC3 with IC₅₀ 7.31 ± 0.48 μM. Moreover, 8d manifested selectivity against PC3 (IC₅₀ = 20.16 ± 0.07 μM), while 8e was selective toward KB-3-1 cell line (IC₅₀ = 21 ± 4.24 μM). Matching with docking profile, the enzymatic assay divulged that 8e is a dual potent single-digit nanomolar inhibitor of VEGFR-2 and EGFR with IC₅₀ values of 24.67 nM and 31.6 nM that were almost equipotent to sorafenib (31.08 nM) and erlotinib (26.79 nM), respectively.