1-Piperazinylphthalazines as potential VEGFR-2 inhibitors and anticancer agents: Synthesis and in vitro biological evaluation

Exploration of the VEGFR-2 inhibition activity of phthalazine derivatives: design, synthesis, cytotoxicity, ADMET, molecular docking and dynamic simulation

Novel phthalazine derivatives were designed, synthesized and evaluated against Hep G2 and MCF-7 as VEGFR-2 inhibitors. In particular, compounds 2g and 4a were found to be the most potent derivatives among all the tested compounds against MCF-7 and Hep G2 cancer cell lines with IC50 values of 0.15 and 0.12 and 0.18 and 0.09 μM respectively. Moreover, compounds 3a, 3c, 5a and 5b displayed excellent anticancer activities against MCF-7 and Hep G2 cancer cell lines. The highly active derivatives 2g, 3a, 3c, 4a, 5a and 5b were evaluated for their inhibitory activities against VEGFR-2. The tested compounds displayed high to low inhibitory activities with IC50 values ranging from 0.148 to 0.892 μM. Among them, compounds 2g and 4a were found to be the most potent derivatives that inhibited VEGFR-2 with IC50 values of 0.148 and 0.196 μM respectively. Compounds 3a, 3c, 5a and 5b exhibited good activity with IC50 values of 0.375, 0.892, 0.548 and 0.331 μM respectively. Sorafenib was used as a reference drug in this study. Molecular modeling studies were carried out for all compounds against the VEGFR-2 active site. The data obtained from biological testing highly correlated with those obtained from molecular modeling studies. Moreover, MD simulation results indicated the stability of ligand-target interaction. Furthermore, our derivatives 2g and 4a showed a good in silico calculated ADMET profile.

Medicinal chemistry perspectives on the development of piperazine-containing HIV-1 inhibitors

The Human immunodeficiency virus (HIV) is the causative agent of acquired immunodeficiency syndrome (AIDS), one of the most perilous diseases known to humankind. A 2023 estimate put the number of people living with HIV around 40 million worldwide, with the majority benefiting from various antiretroviral therapies. Consequently, the urgent need for the development of effective drugs to combat this virus cannot be overstated. In the realm of medicinal and organic chemistry, the synthesis and identification of novel compounds capable of inhibiting HIV enzymes at different stages of their life cycle are of paramount importance. Notably, the spotlight is on the progress made in enhancing the potency of HIV inhibitors through the use of piperazine-based compounds. Multiple studies have revealed that the incorporation of a piperazine moiety results in a noteworthy enhancement of anti-HIV activity. The piperazine ring assumes a pivotal role in shaping the pharmacophore responsible for inhibiting HIV-1 at critical stage, including attachment, reverse transcription, integration, and protease activity. This review also sheds light on the various opportunities that can be exploited to develop effective antiretroviral targets and eliminate latent HIV reservoirs. The advancement of highly potent analogues in HIV inhibitor research has been greatly facilitated by contemporary medicinal strategies, including molecular/fragment hybridization, structure-based drug design, and bioisosterism. These techniques have opened up new avenues for the development of compounds with enhanced efficacy in combating the virus.

New nicotinamide derivatives as potential anticancer agents targeting VEGFR-2: design, synthesis, in vitro, and in silico studies

Herin, new nicotinamide candidates were designed and synthesized as VEGFR-2 inhibitors. In vitro antiproliferative activities were assessed against MCF-7, HepG-2 and HCT-116 cancer cell lines. The top cytotoxic members 15a, 15b, 16, 18a, and 18b were estimated against their selected target (VEGFR-2). Further mechanistic tests were studied for the most potent cytotoxic candidate 18a, these studies revealed the ability of compound 18a to hinder the progression of HCT-116 cells at S and Pre-G1phases besides boosting early and late apoptosis. Also compound 18a was found to significantly decrease the levels immunomodulatory proteins TNF-α and IL-6 while showing a four-fold rise in an apoptotic marker caspase-3 when compared to control cells. The therapeutic index of the designed derivatives was evaluated by computational ADMET and toxicity calculations as well as their potentiality to occupy the VEGFR-2 active site was signposted by molecular docking assessments. Finally, molecular dynamic simulation studies of compound 18a-VEGFR-2 complex indicated the high steadiness of compound 18a in the VEGFR-2 active site. This study presents compound 18a as a lead candidate that can be optimized to get a strong VEGFR-2 inhibitor.Communicated by Ramaswamy H. Sarma.

New benzothiazole hybrids as potential VEGFR-2 inhibitors: design, synthesis, anticancer evaluation, and in silico study

A new series of 2-aminobenzothiazole hybrids linked to thiazolidine-2,4-dione 4a-e, 1,3,4-thiadiazole aryl urea 6a-d, and cyanothiouracil moieties 8a-d was synthesised. The in vitro antitumor effect of the new hybrids was assessed against three cancer cell lines, namely, HCT-116, HEPG-2, and MCF-7 using Sorafenib (SOR) as a standard drug. Among the tested compounds, 4a was the most potent showing IC50 of 5.61, 7.92, and 3.84 µM, respectively. Furthermore, compounds 4e and 8a proved to have strong impact on breast cancer cell line with IC50 of 6.11 and 10.86 µM, respectively. The three compounds showed a good safety profile towards normal WI-38 cells. Flow cytometric analysis of the three compounds in MCF-7 cells revealed that compounds 4a and 4c inhibited cell population in the S phase, whereas 8a inhibited the population in the G1/S phase. The most promising compounds were subjected to a VEGFR-2 inhibitory assay where 4a emerged as the best active inhibitor of VEGFR-2 with IC50 91 nM, compared to 53 nM for SOR. In silico analysis showed that the three new hybrids succeeded to link to the active site like the co-crystallized inhibitor SOR.

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.

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.

Novel 7-Deazapurine Incorporating Isatin Hybrid Compounds as Protein Kinase Inhibitors: Design, Synthesis, In Silico Studies, and Antiproliferative Evaluation

Cancer is a multifactorial disorder with extremely complex genetics and progression. The major challenge in cancer therapy is the development of cancer resistance and relapse. Conventional anticancer drugs directly target the DNA of the cell, while modern chemotherapeutic drugs include molecular-targeted therapy, such as targeting the abnormal cell signaling inside the cancer cells. Targeted chemotherapy is effective in several malignancies; however, the success has always been limited by drug resistance and/or side effects. Anticancer with multi-targeted actions simultaneously modulates multiple cancer cell signaling pathways and, therefore, may ease the chance of effective anticancer drug development. In this research, a series of 7-deazapurine incorporating isatin hybrid compounds was designed and successfully synthesized. Among those hybrids, compound 5 demonstrated a very potent cytotoxic effect compared to the reference anticancer drug against four cancer cell lines. Likewise, compound 5 inhibited the activity of four protein kinase enzymes in nanomolar ranges. Further analysis of the biological evaluation of compound 5 revealed the capability of compound 5 to arrest cell cycle progression and induce programmed cell death. Moreover, molecular simulation studies were performed to investigate the possible types of interactions between compound 5 and the investigated protein kinases. Finally, taking into consideration all the abovementioned findings, compound 5 could be a good candidate for further investigations.

New proapoptotic chemotherapeutic agents based on the quinolone-3-carboxamide scaffold acting by VEGFR-2 inhibition

In the current study, we designed and synthesized a series of new quinoline derivatives 10a-p as antiproliferative agents targeting cancer through inhibition of VEGFR-2. Preliminary molecular docking to assess the interactions of the designed derivatives with the binding site of VEGFR-2 (PDB code: 4ASD) displayed binding poses and interactions comparable to sorafenib. The synthesized compounds exhibited VEGFR-2 inhibitory activity with IC50 ranging from 36 nM to 2.23 μM compared to sorafenib (IC50 = 45 nM), where derivative 10i was the most potent. Additionally, the synthesized derivatives were evaluated in vitro for their cytotoxic activity against HepG2 cancer cell line. Seven compounds 10a, 10c, 10d, 10e, 10i, 10n and 10o (IC50 = 4.60, 4.14, 1.07, 0.88, 1.60, 2.88 and 2.76 μM respectively) displayed better antiproliferative activity than sorafenib (IC50 = 8.38 μM). Compound 10i was tested against Transformed Human Liver Epithelial-2 normal cell line (THLE-2) to evaluate its selective cytotoxicity. Furthermore, 10i, as a potent representative of the series, was assayed for its apoptotic activity and cell cycle kinetics' influence on HepG2, its effects on the gene expression of VEGFR-2, and protein expression of the apoptotic markers Caspase-7 and Bax. Compound 10i proved to have a potential role in apoptosis by causing significant increase in the early and late apoptotic quartiles, a remarkable activity in elevating the relative protein expression of Bax and Caspase-7 and a significant reduction of VEGFR-2 gene expression. Collectively, the obtained results indicate that compound 10i has a promising potential as a lead compound for the development of new anticancer agents.

Therapeutic Approaches in Pancreatic Cancer: Recent Updates

Cancer is a significant challenge for effective treatment due to its complex mechanism, different progressing stages, and lack of adequate procedures for screening and identification. Pancreatic cancer is typically identified in its advanced progression phase with a low survival of ~5 years. Among cancers, pancreatic cancer is also considered a high mortality-causing casualty over other accidental or disease-based mortality, and it is ranked seventh among all mortality-associated cancers globally. Henceforth, developing diagnostic procedures for its early detection, understanding pancreatic cancer-linked mechanisms, and various therapeutic strategies are crucial. This review describes the recent development in pancreatic cancer progression, mechanisms, and therapeutic approaches, including molecular techniques and biomedicines for effectively treating cancer.

Design, synthesis, and docking of novel thiazolidine-2,4-dione multitarget scaffold as new approach for cancer treatment

Novel thiazolidine-2,4-diones have been developed and estimated as conjoint inhibitors of EGFR^T790M and VEGFR-2 against HCT-116, MCF-7, A549, and HepG2 cells. Compounds 6a, 6b, and 6c were known to be the dominant advantageous congeners against HCT116 (IC₅₀  = 15.22, 8.65, and 8.80 µM), A549 (IC₅₀  = 7.10, 6.55, and 8.11 µM), MCF-7 (IC₅₀  = 14.56, 6.65, and 7.09 µM) and HepG2 (IC₅₀  = 11.90, 5.35, and 5.60 µM) mass cell lines, correspondingly. Although compounds 6a, 6b, and 6c disclosed poorer effects than sorafenib (IC₅₀  = 4.00, 4.04, 5.58, and 5.05 µM) against the tested cell sets, congeners 6b and 6c demonstrated higher actions than erlotinib (IC₅₀  = 7.73, 5.49, 8.20, and 13.91 µM) against HCT116, MCF-7 and HepG2 cells, yet lesser performance on A549 cells. The hugely effective derivatives 4e-i and 6a-c were inspected versus VERO normal cell strains. Compounds 6b, 6c, 6a, and 4i were found to be the most effective derivatives, which suppressed VEGFR-2 by IC₅₀  = 0.85, 0.90, 1.50, and 1.80 µM, respectively. Moreover, compounds 6b, 6a, 6c, and 6i could interfere with the EGFR^T790M performing strongest effects with IC₅₀  = 0.30, 0.35, 0.50, and 1.00 µM, respectively. What is more, 6a, 6b, and 6c represented satisfactory in silico computed ADMET profile.

1-Benzyl-5-bromo-3-hydrazonoindolin-2-ones as Novel Anticancer Agents: Synthesis, Biological Evaluation and Molecular Modeling Insights

Human health is experiencing several obstacles in the modern medical era, particularly cancer. As a result, the cancer therapeutic arsenal should be continually expanded with innovative small molecules that preferentially target tumour cells. In this study, we describe the development of two small molecule series (7a–d and 12a–e) based on the 1-benzyl-5-bromoindolin-2-one scaffold that connected through a hydrazone linker to a 4-arylthiazole (7a–d) or 4-methyl-5-(aryldiazenyl)thiazole (12a–e) moiety. The anticancer activity of all the reported indolin-2-one derivatives was assessed against breast (MCF-7) and lung (A-549) cancer cell lines. The 4-arylthiazole-bearing derivatives 7c and 7d revealed the best anticancer activity toward MCF-7 cells (IC50 = 7.17 ± 0.94 and 2.93 ± 0.47, respectively). Furthermore, the VEGFR-2 inhibitory activity for 7c and 7d was evaluated. Both molecules disclosed good inhibitory activity, and their IC50 values were equal to 0.728 µM and 0.503 µM, respectively. Additionally, the impacts of 7d on the cell cycle phases as well as on the levels of different apoptotic markers (caspase-3, caspase-9, Bax, and Bcl-2) were assessed. Molecular docking and dynamic simulations are carried out to explore the binding mode of 7d within the VEGFR-2 active site.

Phthalazone tethered 1,2,3-triazole conjugates: In silico molecular docking studies, synthesis, in vitro antiproliferative, and kinase inhibitory activities

New phthalazone tethered 1,2,3-triazole derivatives 12-21 were synthesized utilizing the Cu(I)-catalyzed click reactions of alkyne-functionalized phthalazone 1 with functionalized azides 2-11. The new phthalazone-1,2,3-triazoles structures 12-21 were confirmed by different spectroscopic tools, like IR; 1H, 13C, 2D HMBC and 2D ROESY NMR; EI MS, and elemental analysis. The antiproliferative efficacy of the molecular hybrids 12-21 against four cancer cell lines was evaluated, including colorectal cancer, hepatoblastoma, prostate cancer, breast adenocarcinoma, and the normal cell line WI38. The antiproliferative assessment of derivatives 12-21 showed potent activity of compounds 16, 18, and 21 compared to the anticancer drug doxorubicin. Compound 16 showed selectivity (SI) towardthe tested cell lines ranging from 3.35 to 8.84 when compared to Dox., that showed SI ranged from 0.75 to 1.61. Derivatives 16, 18 and 21 were assessed towards VEGFR-2 inhibitory activity and result in that derivative 16 showed the potent activity (IC50 = 0.123 µM) in comparison with sorafenib (IC50 = 0.116 µM). Compound 16 caused an interference with the cell cycle distribution of MCF7 and increased the percentage of cells in S phase by 1.37-fold. In silico molecular docking of the effective derivatives 16, 18, and 21 against vascular endothelial growth factor receptor-2 (VEGFR-2) confirmed the formation of stable protein-ligand interactions within the pocket.

Exploration of thiazolidine-2,4-diones as tyrosine kinase inhibitors: Design, synthesis, ADMET, docking, and antiproliferative evaluations

As dual EGFR and VEGFR-2 inhibitors, 22 innovative thiazolidine-2,4-diones were modeled, constructed, and measured for their anticancer performance versus four human neoplasms HCT-116, MCF-7, A549, and HepG2. Molecular docking and MD simulation were performed to inspect the binding technique of the proffered congeners with the EGFR and VEGFR-2 receptors. Evidence realized thanks to the docking inquests was vastly consistent together with that detected through the biological screening. Structures 14a and 14g emerged as the most active compounds toward HCT116 (IC₅₀  = 6.01 and 7.44 µM), MCF-7 (IC₅₀  = 5.77 and 7.23 µM), A549 (IC₅₀  = 5.35 and 5.47 µM) and HepG2 (IC₅₀  = 3.55 and 3.85 µM) tumefaction cells. Compounds 14a and 14g exhibited higher events than sorafenib (IC₅₀  = 5.05, 5.58, 4.04, and 4.00 µM) against HepG2 instead subordinate incidents concerning A549, MCF-7, and HCT116, parallelly. Nevertheless, these compounds signified weightier performance than erlotinib (IC₅₀  = 13.91, 8.20, 5.49, 7.73, and µM), with respect to the four cell lines. Compounds having the best activity against the four cell lines, 12a-f, 13a-d, and 14a-g were chosen to appraise their in vitro VEGFR-2 and EGFR^T790M inhibiting activities. The best results were for compounds 14a and 14g compared to sorafenib and erlotinib, respectively, with IC₅₀ values of 0.74 and 0.78 µM and 0.12 and 0.14 µM, respectively. Moreover, 13d, 14a, and 14g showed an adequate in silico calculated ADMET profile. The current investigation presents novel candidates for future optimization to construct mightier and eclectic binary VEGFR-2/EGFR^T790M restrainers with higher antitumor effects.

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.

Synthesis and Molecular Docking of Some Novel 3-Thiazolyl-Coumarins as Inhibitors of VEGFR-2 Kinase

One crucial strategy for the treatment of breast cancer involves focusing on the Vascular Endothelial Growth Factor Receptor (VEGFR-2) signaling system. Consequently, the development of new (VEGFR-2) inhibitors is of the utmost importance. In this study, novel 3-thiazolhydrazinylcoumarins were designed and synthesized via the reaction of phenylazoacetylcoumarin with various hydrazonoyl halides and α-bromoketones. By using elemental and spectral analysis data (IR, ¹H-NMR, ¹³C-NMR, and Mass), the ascribed structures for all newly synthesized compounds were clarified, and the mechanisms underlying their formation were delineated. The molecular docking studies of the resulting 6-(phenyldiazenyl)-2H-chromen-2-one (3, 6a-e, 10a-c and 12a-c) derivatives were assessed against VEGFR-2 and demonstrated comparable activities to that of Sorafenib (approved medicine) with compounds 6d and 6b showing the highest binding scores (-9.900 and -9.819 kcal/mol, respectively). The cytotoxicity of the most active thiazole derivatives 6d, 6b, 6c, 10c and 10a were investigated for their human breast cancer (MCF-7) cell line and normal cell line LLC-Mk2 using MTT assay and Sorafenib as the reference drug. The results revealed that compounds 6d and 6b exhibited greater anticancer activities (IC₅₀ = 10.5 ± 0.71 and 11.2 ± 0.80 μM, respectively) than the Sorafenib reference drug (IC₅₀ = 5.10 ± 0.49 μM). Therefore, the present study demonstrated that thiazolyl coumarins are potential (VEGFR-2) inhibitors and pave the way for the synthesis of additional libraries based on the reported scaffold, which could eventually lead to the development of efficient treatment for breast cancer.

Discovery of new quinoline and isatine derivatives as potential VEGFR-2 inhibitors: design, synthesis, antiproliferative, docking and MD simulation studies

A new set of quinoline and isatine derivatives were synthesized as antiangiogenic VEGFR-2 inhibitors. On a biological level, the in vitro ability of the obtained candidates to inhibit VEGFR-2 was found to be strong with IC50 values in the range of 76.64-175.50 nM. To investigate the cytotoxicity and safety, all compounds were tested against a panel of four cancer cell lines (A549, Caco2, HepG2 and MDA) as well as two normal cell lines (Vero and WI-38). Interestingly, compound 12 exhibited noticeable cytotoxicity against A549, Caco2 and MDA with IC50 values of 5.40, 0.58 and 0.94 µM, respectively. These results were better and comparable to that of doxorubicin (0.70, 0.82 and 0.90 µM, respectively) with more than three folds higher selectivity index against the Caco2 cell lines. Compound 9 prevented the healing of the cancer cells at a low concentration. Also, the compound's potential to induce programmed cell death in Caco-2 was proved through the significant down regulating of the expression of Bcl2, Bcl-xl and Survivin in addition to the slight upregulation of the TGF-β gene. The cell cycle analysis indicated that compound 9 arrested the Caco-2 cells in the G2/M phase. Interestingly, the molecular docking studies against VEGFR-2 revealed the correct binding of the targeted compounds similar to sorafenib. Furthermore, MD experiments validated the binding of compound 12 with VEGFR-2 over 100 ns, as well as MM-PBSA analysis that confirmed the precise binding with optimum energy. Finally, ADMET analysis showed the general drug-likeness and confirmed the safety of the tested compounds.Communicated by Ramaswamy H. Sarma.

Identification of novel piperazine-tethered phthalazines as selective CDK1 inhibitors endowed with in vitro anticancer activity toward the pancreatic cancer

Pharmacologic inhibition of the oncogenic protein kinases using small molecules is a promising strategy to combat several human malignancies. CDK1 is an example of such a valuable target for the management of pancreatic ductal adenocarcinomas (PDAC); its overexpression in PDAC positively correlates with the size, histological grade and tumor aggressiveness. Here we report the identification of novel series of 1-piperazinyl-4-benzylphthalazine derivatives (8a-g, 10a-i and 12a-d) as promising anticancer agents with CDK1 inhibitory activity. The anti-proliferative activity of these agents was first screened on a panel of 11 cell lines representing 5 cancers (pancreas, melanoma, leukemia, colon and breast), and then confirmed on two CDK1-overexpressing PDAC cell lines (MDA-PATC53 and PL45 cells). Phthalazines 8g, 10d and 10h displayed potent activity against MDA-PATC53 (IC₅₀ = 0.51, 0.88 and 0.73 μM, respectively) and PL45 (IC₅₀ = 0.74, 1.14 and 1.00 μM, respectively) cell lines. Furthermore, compounds 8g, 10d and 10h exhibited potent and selective inhibitory activity toward CDK1 with IC₅₀ spanning in the range 36.80-44.52 nM, whereas they exerted weak inhibitory effect on CDK2, CDK5, AXL, PTK2B, FGFR, JAK1, IGF1R and BRAF kinases. Western blotting of CDK1 in MDA-PATC53 cells confirmed the ability of target phthalazines to diminish the CDK1 levels, and cell cycle analyses revealed their ability to arrest the cell cycle at G2/M phase. In conclusion, a panel of potent and selective CDK1 inhibitors were identified which can serve as lead compounds for designing further CDK1 inhibitors.

Design and synthesis of thiazolidine-2,4-diones hybrids with 1,2-dihydroquinolones and 2-oxindoles as potential VEGFR-2 inhibitors: in-vitro anticancer evaluation and in-silico studies

A thiazolidine-2,4-dione nucleus was molecularly hybridised with the effective antitumor moieties; 2-oxo-1,2-dihydroquinoline and 2-oxoindoline to obtain new hybrids with potential activity against VEGFR-2. The cytotoxic effects of the synthesised derivatives against Caco-2, HepG-2, and MDA-MB-231 cell lines were investigated. Compound 12a was found to be the most potent candidate against the investigated cell lines with IC₅₀ values of 2, 10, and 40 µM, respectively. Furthermore, the synthesised derivatives were tested in vitro for their VEGFR-2 inhibitory activity showing strong inhibition. Moreover, an in vitro viability study against Vero non-cancerous cell line was investigated and the results reflected a high safety profile of all tested compounds. Compound 12a was further investigated for its apoptotic behaviour by assessing the gene expression of four genes (Bcl2, Bcl-xl, TGF, and Survivin). Molecular dynamic simulations authenticated the high affinity, accurate binding, and perfect dynamics of compound 12a against VEGFR-2.

New quinoline and isatin derivatives as apoptotic VEGFR-2 inhibitors: design, synthesis, anti-proliferative activity, docking, ADMET, toxicity, and MD simulation studies

New quinoline and isatin derivatives having the main characteristics of VEGFR-2 inhibitors was synthesised. The antiproliferative effects of these compounds were estimated against A549, Caco-2, HepG2, and MDA-MB-231. Compounds 13 and 14 showed comparable activities with doxorubicin against the Caco-2 cells. These compounds strongly inhibited VEGFR-2 kinase activity. The cytotoxic activities were evaluated against Vero cells. Compound 7 showed the highest value of safety and selectivity. Cell migration assay displayed the ability of compound 7 to prevent healing and migration abilities in the cancer cells. Furthermore, compound 7 induced apoptosis in Caco-2 through the expressive down-regulation of the apoptotic genes, Bcl2, Bcl-xl, and Survivin, and the upregulation of the TGF gene. Molecular docking against VEGFR-2 emerged the interactions of the synthesised compounds in a similar way to sorafenib. Additionally, seven molecular dynamics simulations studies were applied and confirmed the stability of compound 13 in the active pocket of VEGFR-2 over 100 ns.

Anti-cancer and immunomodulatory evaluation of new nicotinamide derivatives as potential VEGFR-2 inhibitors and apoptosis inducers: in vitro and in silico studies

New nicotinamide derivatives 6, 7, 10, and 11 were designed and synthesised based on the essential features of the VEGFR-2 inhibitors. Compound 10 revealed the highest anti-proliferative activities with IC₅₀ values of 15.4 and 9.8 µM against HCT-116 and HepG2, respectively compared to sorafenib (IC₅₀ = 9.30 and 7.40 µM). Compound 7 owned promising cytotoxic activities with IC₅₀ values of 15.7 and 15.5 µM against the same cell lines, respectively. Subsequently, the VEGFR-2 inhibitory activities were assessed for the titled compounds to exhibit VEGFR-2 inhibition with sub-micromolar IC₅₀ values. Moreover, compound 7 induced the cell cycle cessation at the cycle at %G2-M and G0-G1phases, and induced apoptosis in the HCT-116. Compounds 7 and 10 reduced the levels of TNF-α by 81.6 and 84.5% as well as IL-6 by 88.4 and 60.9%, respectively, compared to dexamethasone (82.4 and 93.1%). In silico docking, molecular dynamics simulations, ADMET, and toxicity studies were carried out.

Design, synthesis, anti-proliferative evaluation, docking, and MD simulations studies of new thiazolidine-2,4-diones targeting VEGFR-2 and apoptosis pathway

We report herein, the design and synthesis of thiazolidine-2,4-diones derivatives as new inhibitors for VEGFR-2. The designed members were assessed for their in vitro anticancer activity against four cancer cell lines; A549, Caco-2, HepG-2 and MDA-MB-231. Compound 14a showed the most potent effects against Caco-2, and HepG-2 cell lines (IC50 = of 1.5 and 31.5 μM, respectively). Next, the in vitro VEGFR-2 inhibitory activity, safety profiles and selectivity indices were examined for all the synthesized members against the normal Vero cell line. Compound 14a (the safest member against Caco-2 cell line) was further investigated for its ability to inhibit Caco-2 cells migration and healing. Moreover, the apoptotic induction of compound 14a against Caco-2 cell line was investigated by assessing against four apoptotic genes (Bcl2, Bcl-xl, TGF, and Survivin). The results revealed that compound 14a can exert apoptosis through significant reduction of Bcl2, Survivin, and TGF gene expression levels. Finally, deep computational studies including molecular docking, ADMET, toxicity studies, and MD simulation were carried out. Also, the DFT calculations were performed and discussed, and the results confirmed the inhibitory reactivity of 14a against VEGFR-2. Compound 14a is expected to be used as a potential lead in the development of new VEGFR-2 inhibitors with increased potency.

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.

Synthesis of Novel Phthalazinedione-Based Derivatives with Promising Cytotoxic, Anti-bacterial, and Molecular Docking Studies as VEGFR2 Inhibitors

The parent ester methyl-3-[2-(4-oxo-3-phenyl-3,4-dihydro-phthalazin-1-yloxy)-acetylamino] has 18 compounds. The starting material for alkanoates, their corresponding hydrazides, hydrazones, and dipeptides were produced by chemoselective O-alkylation of 2-phenyl-2,3-dihydrophthalazine-1,4-dione with ethyl chloroacetate(4-oxo-3-phenyl-3,4-dihydro-phthalazin-1-yloxy) acetic acid methyl ester. The starting ester was hydrazinolyzed, then azide coupled with amino acid ester hydrochloride to produce several parent esters, and then hydrazinolyzed to produce parent hydrazides. These hydrazides were used to make a series of dipeptides by reacting them with amino acid ester hydrochloride under azide coupling conditions, and they were also condensed with a number of aldehydes to make the hydrazones. These derivatives were subjected to cytotoxicity against HCT-116 and MDA-MB-231 cells and anti-bacterial and molecular docking studies. Results indicated that the tested compounds, especially 7c and 8b with the phenyl phthalazinone moieties, had promising cytotoxicity against the HCT-116 cells with IC₅₀ values of 1.36 and 2.34 μM, respectively. Additionally, the promising compounds 7c and 8b exhibited poor cytotoxicity against WISH cells with much higher IC₅₀ values, so they were safe against normal cells. Compound 8c exhibited potent anti-bacterial activity with inhibition zones of 12 and 11 mm against Staphylococcus aureus and Escherichia coli, respectively. The molecular docking results of compounds 7c and 8b revealed a good binding disposition and the ligand-receptor interactions like the co-crystallized ligand of the VEGFR2 protein, which may be the proposed mode of action. Finally, compounds 7c and 8b exhibited good ADME pharmacokinetics with good drug-likeness parameters. Hence, detailed studies for the mechanism of action of such compounds are highly recommended for the development of new potent anti-cancer and anti-bacterial agents.

Novel 1,3-Thiazole Analogues with Potent Activity against Breast Cancer: A Design, Synthesis, In Vitro, and In Silico Study

Breast cancer is the most common cancer in women, responsible for over half a million deaths in 2020. Almost 75% of FDA-approved drugs are mainly nitrogen- and sulfur-containing heterocyclic compounds, implying the importance of such compounds in drug discovery. Among heterocycles, thiazole-based heterocyclic compounds have demonstrated a broad range of pharmacological activities. In the present study, a novel set of 1,3-thiazole derivatives was designed and synthesized based on the coupling of acetophenone derivatives, and phenacyl bromide was substituted as a key reaction step. The activity of synthesized compounds was screened against the proliferation of two breast cancer cell lines (MCF-7 and MDA-MB-231). Almost all compounds exhibited a considerable antiproliferative activity toward the breast cancer cells as compared to staurosporine, with no significant cytotoxicity toward the epithelial cells. Among the synthesized compounds, compound 4 exhibited the most potent antiproliferative activity, with an IC₅₀ of 5.73 and 12.15 µM toward MCF-7 and MDA-MB-231 cells, respectively, compared to staurosporine (IC₅₀ = 6.77 and 7.03 µM, respectively). Exploring the mechanistic insights responsible for the antiproliferative activity of compound 4 revealed that compound 4 possesses a significant inhibitory activity toward the vascular endothelial growth factor receptor-2 (VEGFR-2) with (IC₅₀ = 0.093 µM) compared to Sorafenib (IC₅₀ = 0.059 µM). Further, compound 4 showed the ability to induce programmed cell death by triggering apoptosis and necrosis in MCF-7 cells and to induce cell cycle arrest on MCF-7 cells at the G1 stage while decreasing the cellular population in the G2/M phase. Finally, detailed in silico molecular docking studies affirmed that this class of compounds possesses a considerable binding affinity toward VEGFR2 proteins. Overall, these results indicate that compound 4 could be a promising lead compound for developing potent anti-breast cancer compounds.

New [1,2,4]triazolo[4,3-c]quinazoline derivatives as vascular endothelial growth factor receptor-2 inhibitors and apoptosis inducers: Design, synthesis, docking, and antiproliferative evaluation

In continuation of our previous efforts in the field of design and synthesis of vascular endothelial growth factor receptor (VEGFR)-2 inhibitors, a new series of [1,2,4]triazolo[4,3-c]quinazoline derivatives were designed and synthesized as modified analogs of some reported VEGFR-2 inhibitors. The synthesized compounds were designed to have the essential pharmacophoric features of VEGFR-2 inhibitors. Antiproliferative activities of the synthesized compounds were investigated against two tumor cell lines (HepG2 and HCT-116) using sorafenib as a positive control. Compound 10k emerged as the most promising antiproliferative agent with IC₅₀ values of 4.88 and 5.21 µM against HepG2 and HCT-116 cells, respectively. Also, it showed the highest inhibitory activity against VEGFR-2 with an IC₅₀ value of 53.81 nM compared to sorafenib (IC₅₀  = 44.34 nM). Cell cycle analysis revealed that compound 10k can arrest HepG2 cells at both the S and G2/M phases. In addition, this compound produced a tenfold increase in apoptotic cells compared to the control. Furthermore, the effect of compound 10k on the expression level of BAX, Bcl-2, and caspase-3 was assessed. This compound caused a 3.35-fold increase in BAX expression levels and a 1.25-fold reduction in Bcl-2 expression levels. The BAX/Bcl-2 ratio was calculated to be 4.57, indicating a promising apoptotic effect. It also showed a significant increase in the level of caspase-3 (4.12-fold) compared to the control cells. In silico docking, absorption, distribution, metabolism, excretion, and toxicity, and toxicity studies were performed for the synthesized compounds to investigate their binding patterns against the proposed biological target (VEGFR-2) and to assess the drug-likeness characters.

Design, Synthesis, In Silico and In Vitro Studies of New Immunomodulatory Anticancer Nicotinamide Derivatives Targeting VEGFR-2

VEGFR-2, the subtype receptor tyrosine kinase (RTK) responsible for angiogenesis, is expressed in various cancer cells. Thus, VEGFER-2 inhibition is an efficient approach for the discovery of new anticancer agents. Accordingly, a new set of nicotinamide derivatives were designed and synthesized to be VEGFR-2 inhibitors. The chemical structures were confirmed using IR, 1H-NMR, and 13C-NMR spectroscopy. The obtained compounds were examined for their anti-proliferative activities against the human cancer cell lines (HCT-116 and HepG2). VEGFR-2 inhibitory activities were determined for the titled compounds. Compound 8 exhibited the strongest anti-proliferative activities with IC50 values of 5.4 and 7.1 µM against HCT-116 and HepG2, respectively. Interestingly, compound 8 was the most potent VEGFR-2 inhibitor with an IC50 value of 77.02 nM (compare to sorafenib: IC50 = 53.65 nM). Treatment of HCT-116 cells with compound 8 produced arrest of the cell cycle at the G0–G1 phase and a total apoptosis increase from 3.05 to 19.82%—6.5-fold in comparison to the negative control. In addition, compound 8 caused significant increases in the expression levels of caspase-8 (9.4-fold) and Bax (9.2-fold), and a significant decrease in the Bcl-2 expression level (3-fold). The effects of compound 8 on the levels of the immunomodulatory proteins (TNF-α and IL-6) were examined. There was a marked decrease in the level of TNF-α (92.37%) compared to the control (82.47%) and a non-significant reduction in the level of IL-6. In silico docking, molecular dynamics simulations, and MM-PBSA studies revealed the high affinity, the correct binding, and the optimum dynamics of compound 8 inside the active site of VEGFR-2. Finally, in silico ADMET and toxicity studies indicated acceptable values of drug-likeness. In conclusion, compound 8 has emerged as a promising anti-proliferative agent targeting VEGFR-2 with significant apoptotic and immunomodulatory effects.

Nanogel-mediated drug delivery system for anticancer agent: pH stimuli responsive poly(ethylene glycol/acrylic acid) nanogel prepared by gamma irradiation

The popularity of nanogel as nano drug carrier lies in its adjustable physical properties, and the ability to encapsulate drug particles with improved properties is being developed to meet the diverse pH-sensitive nanogel for anticancer agent. Monitoring pH has been identified as an important diagnostic element during the treatment process. A pH-sensitive nanogel consisting of (PEG/PMAc) in the ratio of (50:50%) hasbeen cross-linkedby γ-irradiation techniques at an irradiation dose of 5 kGy. Compound 4 and its nanogel 5 were synthesized and assessed for their anticancer effects against HepG2, A549, MCF-7 and HCT-116 as dual VEGFR-2 and EGFR tyrosine kinases inhibitors. The molecular design was performed to investigate the binding mode of compound 4 with VEGFR-2 and EGFR receptors. Our compound 5 in nanogel showed enhanced anticancer activities against the four tested cancer cell lines and also showed higher inhibition activities against VEGFR-2 and EGFR^T790M kinases than the derivative 4. Finally, our derivative 4 showed good in silico calculated ADMET profile. It was expected to show good GIT absorption in human, lower CNS side effects, no hepatotoxic actions and higher acute and oral chronic toxic doses in comparing to sorafenib and erlotinib. The obtained results showed that, our compound could be useful as a template for future design, optimization, adaptation and investigation to produce more potent and selective dual VEGFR-2/EGFR^T790M inhibitors with higher anticancer activity.

Design, synthesis, in silico docking, ADMET and anticancer evaluations of thiazolidine-2,4-diones bearing heterocyclic rings as dual VEGFR-2/EGFRT790M tyrosine kinase inhibitors

Fourteen recent thiazolidine-2,4-diones bearing furan and/or thiophene heterocyclic rings have been designed, synthesized and assessed for their anticancer activities against four human tumor cell lines HepG2, A549, MCF-7 and HCT-116 targeting both VEGFR-2 and EGFR tyrosine kinases. Molecular design was carried out to investigate the binding mode of the proposed compounds with VEGFR-2 and EGFR receptors. HepG2 was the most susceptible cell line to the influence of our derivatives. Compounds 5g and 4g revealed the highest activities against HepG2 (IC₅₀ = 3.86 and 6.22 μM), A549 (IC₅₀ = 7.55 and 12.92 μM), MCF-7 (IC₅₀ = 10.65 and 10.66 μM) and HCT116 (IC₅₀ = 9.04 and 11.17 μM) tumor cell lines. Sorafenib (IC₅₀ = 4.00, 4.04, 5.58 and 5.05 μM) and elotinib (IC₅₀ = 7.73, 5.49, 8.20 and 13.91 μM) were used as reference standards. Furthermore, the most active cytotoxic compounds 4d, 4e, 4f, 4g, 5d, 5e, 5f and 5g were selected to assess their VEGFR-2 inhibitory effects. Derivatives 5g, 4g and 4f were observed to be the highest effective derivatives that inhibited VEGFR-2 at the submicromolar level (IC₅₀ = 0.080, 0.083 and 0.095 μM respectively) in comparison to sorafenib (IC₅₀ = 0.084 μM). As well, compounds 4d, 4e, 4f, 4g, 5d, 5e, 5f and 5g were additionally assessed for their inhibitory activities against mutant EGFR^T790M. Compounds 5g and 4g could interfere with the EGFR^T790M activity exhibiting stronger activities than elotinib with IC₅₀ = 0.14 and 0.23 μM respectively. Finally, our derivatives 4g, 5f and 5g showed a good in silico calculated ADMET profile. The obtained results showed that our compounds could be useful as a template for future design, optimization, adaptation and investigation to produce more potent and selective dual VEGFR-2/EGFR^T790M inhibitors with higher anticancer activity.

New Series of VEGFR-2 Inhibitors and Apoptosis Enhancers: Design, Synthesis and Biological Evaluation

Background

Cancer is still a major world health threat, causing a high rate of mortality. VEGFR-2 inhibitor anticancer agents are of great significance. However, they showed some serious side effects.

Purpose

To discover new effective and safer anticancer agents, a new series of piperazinylquinoxaline-based derivatives was designed and synthesized on the basis of the pharmacophoric features of VEGFR-2 inhibitor drugs.

Methods

The new candidates were evaluated against A549 lung cancer cells, HepG-2 hepatoma cells, Caco-2 colon cancer cells, MDA breast cancer cells, and VEGFR-2 kinase. Moreover, cell cycle kinetics and apoptosis rates were studied in HepG-2 cells treated with compound 11, which was the most promising candidate.

Results

The new derivatives revealed better antitumor results (IC₅₀ from 6.48 to 38.58 µM) against the aforementioned cancer cell lines than sorafenib. Also, the new candidates showed VEGFR-2 inhibition with IC₅₀ values ranging from 0.19 to 0.60 µM compared to 0.08 µM for sorafenib. Compound 11, meanwhile, showed IC₅₀ values equal to 10.61, 9.52, 12.45, 11.52, and 0.19 µM against the cancer cell lines and VEGFR-2, respectively. Moreover, compound 11 raised the apoptosis rate in HepG-2 cells from 5% to 44% and caused 4, 2.3, and 3-fold increases in BAX/Bcl-2 ratio, caspase-3 level, and P53 expression, respectively, compared to control untreated cells. Finally, the new derivatives displayed the correct binding mode into VEGFR-2 kinase pocket, giving interactions with the essential residues.

Conclusion

This work suggests that compound 11 is a very significant anticancer candidate, and piperazinylquinoxaline is an important scaffold in the development of new potential effective and safer VEGFR-2 inhibitor agents.

Controlled microwave-assisted reactions: A facile synthesis of polyfunctionally substituted phthalazines as dual EGFR and PI3K inhibitors in CNS SNB-75 cell line

Brain tumors are stubborn cancers with poor prognosis and disappointing survival rates. Targeted cancer therapeutics with higher efficacy and lower resistance are highly demanded. An efficient one-pot synthesis of polyfunctionalized phthalazines derivatives was developed by reacting ethyl 1-aryl-5-cyano-1,6-dihydro-4-methyl-6-oxo-3-pyridazine-carboxylates with cinnamonitrile derivatives and the cycloaddition reaction of thieno[3,4-d]pyridazines with activated double or triple bond systems under controlled microwave heating with high yields. The resultant synthesized phthalazines (5a-e, 9 and 13) were tested for their in vitro anti-cancer activities by using in vitro one dose assay at National Cancer institute, USA. Only phthalazine (5b) showed broad spectrum anti-tumor activity against most tested cancer cell lines from all subpanels with mean % GI = 22.61. Interestingly, all tested compounds showed varying growth inhibitory activity against a particular cell line, CNS SNB-75 cell line, but (5b) exhibited the highest growth inhibitory activity against CNS-SNB-75 cell line with (GI% = 108.81) and (IC₅₀ = 3.703 ± 0.2) compared to erlotinib; (IC₅₀ = 12.5 ± 0.68). It caused Pre-G1 apoptosis and growth arrest at S phase. It also increased percentage of the total apoptotic cells in CNS-SNB-75 cell line (39.26%) compared to control cells (2.17%) in the annexin V-FITC experiment. It revealed pronounced EGFR inhibitory activity (IC₅₀ = 47.27 ± 2.41 ng/mL) compared to erlotinib (IC₅₀ = 30.7 ± 1.56 ng/mL). It also inhibited the different PI3K isoforms α, β, γ and δ (with IC₅₀ of 4.39, 13.6, 12.5 and 3.11 μg/mL, respectively compared to LY294002 (with IC₅₀ of 12.7, 8.57, 6.89 and 5.7 μg/mL, respectively). It also caused significant lower protein expression levels of pPI3K, AKT, pAKT and Bcl2 and higher protein expression levels of BAX, Casp3 and Casp9 when compared to untreated cells. Conclusion: Phthalazine (5b) may be an effective, convenient and safe anti-cancer agent acting via proapoptotic and dual EGFR and PI3K kinase inhibitory actions in CNS SNB-75 cell line.

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.

An overview of in silico methods used in the design of VEGFR-2 inhibitors as anticancer agents

VEGFR-2 enzyme known for physiological functioning of the cell also involves in pathological angiogenesis and tumor progression. Recently VEGFR-2 has gained the interest of researchers all around the world as a promising target for the drug design and discovery of new anticancer agents. VEGFR2 inhibitors are a major class of anticancer agents used for clinical purposes. In silico methods like virtual screening, molecular docking, molecular dynamics, pharmacophore modeling, and other computational approaches help extensively in identifying the main molecular interactions necessary for the binding of the small molecules with the respective protein target to obtain the expected pharmacological potency. In this chapter, we discussed some representative case studies of in silico techniques used to determine molecular interactions and rational drug design of VEGFR-2 inhibitors as anticancer agents.

Multicomponent synthesis of novel β-carboline-fused imidazolium derivatives via the Mannich reaction: cytotoxicity, molecular docking, and mechanistic studies as angiogenesis inhibitors

Herein we report novel multicomponent reactions for the synthesis of β-carboline-fused imidazolium derivatives via the Mannich-type reaction.

Targeting VEGFR-2 by new quinoxaline derivatives: Design, synthesis, antiproliferative assay, apoptosis induction, and in silico studies

Twelve new triazolo[4,3-a]quinoxaline-based compounds are reported as anticancer agents with potential effects against vascular endothelial growth factor receptor-2 (VEGFR-2), using sorafenib as a reference molecule. With sorafenib as the positive control, the antiproliferative effects of the synthesized compounds against MCF-7 and HepG2 cells, as well as their VEGFR-2-inhibitory activities, were assessed. The most powerful VEGFR-2 inhibitor was compound 14a, which had an IC₅₀ value of 3.2 nM, which is very close to that of sorafenib (IC₅₀  = 3.12 nM). Furthermore, compounds 14c and 15d showed potential inhibitory activity against VEGFR-2, with IC₅₀ values of 4.8 and 5.4 nM, respectively. Compound 14a caused apoptosis in HepG2 cells and stopped the cell cycle at the G2/M phase. In HepG2 cells, it also increased the levels of the proteases caspase-3 and caspase-9, as well as the Bax/Bcl-2 ratio. In silico ADMET (absorption, distribution, metabolism, excretion, and toxicity) and toxicity experiments revealed that the synthesized agents had acceptable drug-likeness.

Discovery of new 3-methylquinoxalines as potential anti-cancer agents and apoptosis inducers targeting VEGFR-2: design, synthesis, and in silico studies

There is an urgent need to design new anticancer agents that can prevent cancer cell proliferation even with minimal side effects. Accordingly, two new series of 3-methylquinoxalin-2(1H)-one and 3-methylquinoxaline-2-thiol derivatives were designed to act as VEGFR-2 inhibitors. The designed derivatives were synthesised and evaluated in vitro as cytotoxic agents against two human cancer cell lines namely, HepG-2 and MCF-7. Also, the synthesised derivatives were assessed for their VEGFR-2inhibitory effect. The most promising member 11e were further investigated to reach a valuable insight about its apoptotic effect through cell cycle and apoptosis analyses. Moreover, deep investigations were carried out for compound 11e using western-plot analyses to detect its effect against some apoptotic and apoptotic parameters including caspase-9, caspase-3, BAX, and Bcl-2. Many in silico investigations including docking, ADMET, toxicity studies were performed to predict binding affinity, pharmacokinetic, drug likeness, and toxicity of the synthesised compounds. The results revealed that compounds 11e, 11g, 12e, 12g, and 12k exhibited promising cytotoxic activities (IC50 range is 2.1 - 9.8 µM), comparing to sorafenib (IC50 = 3.4 and 2.2 µM against MCF-7 and HepG2, respectively). Moreover, 11b, 11f, 11g, 12e, 12f, 12g, and 12k showed the highest VEGFR-2 inhibitory activities (IC50 range is 2.9 - 5.4 µM), comparing to sorafenib (IC50 = 3.07 nM). Additionally, compound 11e had good potential to arrest the HepG2 cell growth at G2/M phase and to induce apoptosis by 49.14% compared to the control cells (9.71%). As well, such compound showed a significant increase in the level of caspase-3 (2.34-fold), caspase-9 (2.34-fold), and BAX (3.14-fold), and a significant decrease in Bcl-2 level (3.13-fold). For in silico studies, the synthesised compounds showed binding mode similar to that of the reference compound (sorafenib).

Discovery of new VEGFR-2 inhibitors based on bis([1, 2, 4]triazolo)[4,3-a:3',4'-c]quinoxaline derivatives as anticancer agents and apoptosis inducers

Herein, a new wave of bis([1, 2, 4]triazolo)[4,3-a:3',4'-c]quinoxaline derivatives have been successfully designed and synthesised. The synthesised derivatives were biologically investigated for their cytotoxic activities against HepG2 and MCF-7. Also, the tested compounds were further examined in vitro for their VEGFR-2 inhibitory activity. The most promising derivative 23j was further investigated for its apoptotic behaviour in HepG2 cell lines using flow cytometric and western-plot analyses. Additional in-silico studies were performed to predict how the synthesised compounds can bind to VEGFR-2 and to determine the drug-likeness profiling of these derivatives. The results revealed that compounds 23a, 23i, 23j, 23l, and 23n displayed the highest antiproliferative activities against the two cell lines with IC50 values ranging from 6.4 to 19.4 µM. Furthermore, compounds 23a, 23d, 23h, 23i, 23j, 23l, 23 m, and 23n showed the highest VEGFR-2 inhibitory activities with IC50 values ranging from 3.7 to 11.8 nM, comparing to sorafenib (IC50 = 3.12 nM). Moreover, compound 23j arrested the HepG2 cell growth at the G2/M phase and induced apoptosis by 40.12% compared to the control cells (7.07%). As well, such compound showed a significant increase in the level of caspase-3 (1.36-fold), caspase-9 (2.80-fold), and BAX (1.65-fold), and exhibited a significant decrease in Bcl-2 level (2.63-fold).

Design, synthesis, docking, ADMET studies, and anticancer evaluation of new 3-methylquinoxaline derivatives as VEGFR-2 inhibitors and apoptosis inducers

Vascular endothelial growth factor receptor-2 (VEGFR-2) plays a critical role in cancer angiogenesis. Inhibition of VEGFR-2 activity proved effective suppression of tumour propagation. Accordingly, two series of new 3-methylquinoxaline derivatives have been designed and synthesised as VEGFR-2 inhibitors. The synthesised derivatives were evaluated in vitro for their cytotoxic activities against MCF-7and HepG2 cell lines. In addition, the VEGFR-2 inhibitory activities of the target compounds were estimated to indicate the potential mechanism of their cytotoxicity. To a great extent, the results of VEGFR-2 inhibition were highly correlated with that of cytotoxicity. Compound 27a was the most potent VEGFR-2 inhibitor with IC50 of 3.2 nM very close to positive control sorafenib (IC50 = 3.12 nM). Such compound exhibited a strong cytotoxic effect against MCF-7 and HepG2, respectively with IC50 of 7.7 and 4.5 µM in comparison to sorafenib (IC50 = 3.51 and 2.17 µM). In addition, compounds 28, 30f, 30i, and 31b exhibited excellent VEGFR-2 inhibition activities (IC50 range from 4.2 to 6.1 nM) with promising cytotoxic activity. Cell cycle progression and apoptosis induction were investigated for the most active member 27a. Also, the effect of 27a on the level of caspase-3, caspase-9, and BAX/Bcl-2 ratio was determined. Molecular docking studies were implemented to interpret the binding mode of the target compounds with the VEGFR-2 pocket. Furthermore, toxicity and ADMET calculations were performed for the synthesised compounds to study their pharmacokinetic profiles.

Synthesis, in vitro anticancer activity and in silico studies of certain pyrazole-based derivatives as potential inhibitors of cyclin dependent kinases (CDKs)

New diphenyl-1H-pyrazoles were synthesized and screened for CDK2 inhibition where 8d, 9b, 9c, and 9e exhibited promising activity (IC₅₀ = 51.21, 41.36, 29.31, and 40.54 nM respectively) compared to R-Roscovitine (IC₅₀ = 43.25 nM). Furthermore, preliminary anti-proliferative activity screening of some selected compounds on 60 cancer cell lines was performed at the (NCI/USA). Compounds 8a-c displayed promising growth inhibitory activity (mean %GI; 73.74, 94.32 and 74.19, respectively). Additionally, they were further selected by the NCI for five-dose assay, exhibiting pronounced activity against almost the full panel (GI₅₀ ranges; 0.181-5.19, 1.07-4.12 and 1.07-4.82 µM, respectively) and (Full panel GI₅₀ (MG-MID); 2.838, 2.306 and 2.770 µM, respectively). Screening the synthesized compounds 8a-c for inhibition of CDK isoforms revealed that compound 8a exhibited nearly equal inhibition to all the tested CDK isoforms, while compound 8b inhibits CDK4/D1 preferentially than the other isoforms and compound 8c inhibits CDK1, CDK2 and CDK4 more than CDK7. Flow cytometry cell cycle assay of 8a-c on Non-small cell lung carcinoma (NSCL HOP-92) cell line revealed S phase arrest by 8a and G1/S phase arrest by 8b and 8c. Apoptotic induction in HOP-92 cell line was also observed upon treatment with compounds 8a-c. Docking to CDK2 ATP binding site revealed similar interactions as the co-crystallized ligand R-Roscovitine (PDB code; 3ddq). These findings present compounds 8a-c as promising anti-proliferative agents.

Discovery of Oral Anticancer 1,2-Bis(hydroxymethyl)benzo[g]pyrrolo[2,1-a]phthalazine Hybrids That Inhibit Angiogenesis and Induce DNA Cross-Links

Designing hybrid molecules with dual functions is one approach to improve the therapeutic efficacy of combination treatment. We have previously conjugated phthalazine and bis(hydroxymethyl)pyrrole pharmacophores to form hybrids bearing antiangiogenesis and DNA interstrand cross-linking activities. To improve the bioavailability, we adopted a benzology approach to design and synthesize a new series of 1,2-bis(hydroxymethyl)benzo[g]pyrrolo[2,1-a]phthalazines. These new hybrids retained the dual functions and could be formulated into vehicles for intravenous and oral administration. Among them, we demonstrated that compound 19a with dimethylamine at the C6 position markedly suppressed the tumor growth of human small cell lung cancer cell line H526, squamous lung cancer cell line H520, and renal cancer cell line 786-O in nude mice, implying that compound 19a is a broad-spectrum anticancer agent. Our results implicated that the conjugation of antiangiogenic and DNA cross-linking is likely to be a helpful approach to improving the efficacy of combination therapy.

New quinoxaline-based VEGFR-2 inhibitors: design, synthesis, and antiproliferative evaluation with in silico docking, ADMET, toxicity, and DFT studies

A new series of 3-methylquinoxaline-based derivatives having the same essential pharmacophoric features as VEGFR-2 inhibitors have been synthesized and evaluated for their antiproliferative activities against two human cancer cell lines, MCF-7 and HepG-2. Compounds 15b and 17b demonstrated a significant antiproliferative effect with IC₅₀ ranging from 2.3 to 5.8 μM. An enzymatic assay was carried out for all the tested candidates against VEGFR-2. Compound 17b was the most potent VEGFR-2 inhibitor (IC₅₀ = 2.7 nM). Mechanistic investigation including cell cycle arrest and apoptosis was performed for compound 17b against HepG-2 cells, and the results revealed that 17b induced cell apoptosis and arrested cell cycle in the G2/M phase. Moreover, apoptosis analyses were conducted for compound 17b to evaluate its apoptotic potential. The results showed upregulation in caspase-3 and caspase-9 levels, and improving the Bax/Bcl-2 ratio by more than 10-fold. Docking studies were performed to determine the possible interaction with the VEGFR-2 active site. Further docking studies were carried out for compound 17b against cytochrome P450 to present such compounds as non-inhibitors. In silico ADMET, toxicity, and physico-chemical properties revealed that most of the synthesized members have acceptable values of drug-likeness. Finally, DFT studies were carried out to calculate the thermodynamic, molecular orbital and electrostatic potential properties.

Pharmacophore-linked pyrazolo[3,4-d]pyrimidines as EGFR-TK inhibitors: Synthesis, anticancer evaluation, pharmacokinetics, and in silico mechanistic studies

Targeting the epidermal growth factor receptors (EGFRs) with small inhibitor molecules has been validated as a potential therapeutic strategy in cancer therapy. Pyrazolo[3,4-d]pyrimidine is a versatile scaffold that has been exploited for developing potential anticancer agents. On the basis of fragment-based drug discovery, considering the essential pharmacophoric features of potent EGFR tyrosine kinase (TK) inhibitors, herein, we report the design and synthesis of new hybrid molecules of the pyrazolo[3,4-d]pyrimidine scaffold linked with diverse pharmacophoric fragments with reported anticancer potential. These fragments include hydrazone, indoline-2-one, phthalimide, thiourea, oxadiazole, pyrazole, and dihydropyrazole. The synthesized molecules were evaluated for their anticancer activity against the human breast cancer cell line, MCF-7. The obtained results revealed comparable antitumor activity with that of the reference drugs doxorubicin and toceranib. Docking studies were performed along with EGFR-TK and ADMET profiling studies. The results of the docking studies showed the ability of the designed compounds to interact with key residues of the EGFR-TK through a number of covalent and noncovalent interactions. The obtained activity of compound 25 (IC50  = 2.89 µM) suggested that it may serve as a lead for further optimization and drug development.

Design, synthesis and molecular docking of new [1,2,4] triazolo[4,3-a]quinoxaline derivatives as anticancer agents targeting VEGFR-2 kinase

Vascular endothelial growth factor receptor-2 (VEGFR-2) is critically involved in cancer angiogenesis. Blocking of VEGFR-2 signaling pathway proved effective suppression of tumor growth. Accordingly, two series of new triazoloquinoxaline-based derivatives were designed and synthesized as VEGFR-2 inhibitors. All in vitro cytotoxic activities of the synthesized compounds were evaluated against two human cancer cell lines (MCF-7 and HepG2). To confirm the potential mechanism of cytotoxicity, enzymatic assays against VEGFR-2 were estimated for all the target compounds. The results of VEGFR-2 inhibitory activity and cytotoxicity were in high correlation. Compound 22a exhibited the highest cytotoxic effect with IC₅₀ values of 6.2 and 4.9 μM against MCF-7 and HepG2, respectively, comparing to sorafenib (IC₅₀ = 3.53 and 2.18 μM). Such derivative showed the best VEGFR-2 inhibitory activity with an IC₅₀ value of 3.9 nM, which is very close to that of sorafenib (IC₅₀ = 3.13 nM). Moreover, compounds 22b, 23b, and 23e exhibited strong cytotoxic activity with IC₅₀ values ranging from 11.7 to 15.3 μM. Also, these compounds showed promising VEGFR-2 inhibition with IC₅₀ values of 4.2, 5.7, and 4.7 nM, respectively. In silico docking, ADMET, and toxicity studies were carried out for the synthesized compounds. The results revealed that some compounds have a good binding mode against VEGFR-2 and a high level of drug-likeness.