[1,2,4]Triazolo[4,3-c]quinazoline and bis([1,2,4]triazolo)[4,3-a:4′,3′-c]quinazoline derived DNA intercalators: Design, synthesis, in silico ADMET profile, molecular docking and anti-proliferative evaluation studies

Quinazolines annelated at the N(3)-C(4) bond: Synthesis and biological activity

This review covers article and patent data obtained mostly within the period 2013-2023 on the synthesis and biological activity of quinazolines [c]-annelated by five- and six-membered heterocycles. Pyrazolo-, benzimidazo-, triazolo- and pyrimido- [c]quinazoline systems have shown multiple potential activities against numerous targets. We highlight that most research efforts are directed to design of anticancer and antibacterial agents of azolo[c]quinazoline nature. This review emphases both on the medicinal chemistry aspects of pyrrolo[c]-, azolo[c]- and azino[c]quinazolines and comprehensive synthetic strategies of quinazolines annelated at N(3)-C(4) bond in the perspective of drug development and discovery.

Revisiting methotrexate and phototrexate Zinc15 library-based derivatives using deep learning in-silico drug design approach

Introduction: Cancer is the second most prevalent cause of mortality in the world, despite the availability of several medications for cancer treatment. Therefore, the cancer research community emphasized on computational techniques to speed up the discovery of novel anticancer drugs. Methods: In the current study, QSAR-based virtual screening was performed on the Zinc15 compound library (271 derivatives of methotrexate (MTX) and phototrexate (PTX)) to predict their inhibitory activity against dihydrofolate reductase (DHFR), a potential anticancer drug target. The deep learning-based ADMET parameters were employed to generate a 2D QSAR model using the multiple linear regression (MPL) methods with Leave-one-out cross-validated (LOO-CV) Q2 and correlation coefficient R2 values as high as 0.77 and 0.81, respectively. Results: From the QSAR model and virtual screening analysis, the top hits (09, 27, 41, 68, 74, 85, 99, 180) exhibited pIC50 ranging from 5.85 to 7.20 with a minimum binding score of -11.6 to -11.0 kcal/mol and were subjected to further investigation. The ADMET attributes using the message-passing neural network (MPNN) model demonstrated the potential of selected hits as an oral medication based on lipophilic profile Log P (0.19-2.69) and bioavailability (76.30% to 78.46%). The clinical toxicity score was 31.24% to 35.30%, with the least toxicity score (8.30%) observed with compound 180. The DFT calculations were carried out to determine the stability, physicochemical parameters and chemical reactivity of selected compounds. The docking results were further validated by 100 ns molecular dynamic simulation analysis. Conclusion: The promising lead compounds found endorsed compared to standard reference drugs MTX and PTX that are best for anticancer activity and can lead to novel therapies after experimental validations. Furthermore, it is suggested to unveil the inhibitory potential of identified hits via in-vitro and in-vivo approaches.

DNA-Targeted Complexes of Tc and Re for Biomedical Applications

Due to their favorable chemical features, Re and Tc complexes have been widely used for the development of new therapeutic agents and imaging probes to solve problems of biomedical relevance. This review provides an update of the most relevant research efforts towards the development of novel cancer theranostic agents using Re and Tc-based compounds interacting with specific DNA structures. This includes a variety of homometallic complexes, namely those containing M(CO)3 (M=Re, Tc) moieties, that exhibit different modes of interaction with DNA, such as covalent binding, intercalation, groove binding or G-quadruplex DNA binding. Additionally, heterometallic complexes, designed to potentiate synergistic effects of different metal centers to improve DNA-targeting, cytotoxicity and fluorescence properties, are also reviewed. Particular attention is also given to 99m Tc- and 188 Re-labeled oligonucleotides that have been widely explored to develop imaging and therapeutic radiopharmaceuticals through the in vivo hybridization with a specific complementary DNA or RNA target sequence to provide useful molecular tools in precision medicine for cancer diagnosis and treatment. Finally, the need for further improvement of DNA-targeted Re and Tc-based compounds as potential therapeutic and diagnostic agents is highlighted, and future directions are discussed.

Novel dihydrobenzofuran derivatives: design, synthesis, cytotoxic activity, apoptosis, molecular modelling and DNA binding studies

Pyrazoline derivatives (3a-3e) and (4a-4e) were designed and synthesized through chalcones (2a-2e) cyclization with NH2NH2/HCOOH and NH2CSNHNH2/CH3COOH, respectively. The molecular structures were elucidated by using various techniques such as UV-visible, FT-IR, 1H, 13C NMR spectroscopy and mass spectrometry. The purity of all synthesized compounds was checked by the liquid chromatography-mass spectrometry (LC-MS). Single X-ray crystallography was confirmed the molecular structure of analogs (2d, 3e and 4e). Anticancer activity of the all derivatives was screened against human cancer cell MCF-7 and HepG2 cell lines by MTT assay. The results of anticancer activity of novel analogs 2b, 3b and 3e exhibited promising activity against MCF-7 but low toxic against the HepG2 normal cell line. By using a flow cytometry-based technique, the anticancer effectiveness of potent compounds against the MCF-7 cancer cell line was further validated. DNA binding interactions of the novel analogs 3b and 3e were carried out with calf thymus DNA (Ct-DNA) using absorption, fluorescence, circular dichroism and cyclic voltammetry. In silico molecular modelling of pyrazoline derivatives were also studied using Schrödinger-Maestro v2021-2 against tyrosine kinase receptor with PDB ID: 1M17 to explore their best hits. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical was used to measure the antioxidant capacity of active pyrazoline derivatives. Using Swiss ADMET software, the ADMET characteristics of pyrazoline derivatives were also investigated.Communicated by Ramaswamy H. Sarma.

New 1,3,4-thiadiazoles as potential anticancer agents: pro-apoptotic, cell cycle arrest, molecular modelling, and ADMET profile

A series of novel 1,3,4-thiadiazoles was synthesized via the reaction of N-(5-(2-cyanoacetamido)-1,3,4-thiadiazol-2-yl)benzamide (3) with different carbon electrophiles and evaluated as potential anticancer agents. The chemical structures of these derivatives were fully elucidated using various spectral and elemental analyses. Out of 24 new thiadiazoles, derivatives 4, 6b, 7a, 7d, and 19 have significant antiproliferative activity. However, derivatives 4, 7a, and 7d were toxic to the normal fibroblasts, and therefore were excluded from further investigations. Derivatives 6b and 19 with IC50 at less than 10 μM and with high selectivity were selected for further studies in breast cells (MCF-7). Derivative 19 arrested the breast cells at G2/M probably through inhibition of CDK1, while 6b significantly increased the sub-G1 percent of cells probably through induction of necrosis. These results were confirmed by the annexin V-PI assay where 6b did not induce apoptosis and increased the necrotic cells to 12.5%, and compound 19 significantly increased the early apoptosis to 15% and increased the necrotic cells to 15%. Molecular docking showed that compound 19 was like FB8, an inhibitor of CDK1, in binding the CDK1 pocket. Therefore, compound 19 could be a potential CDK1 inhibitor. Derivatives 6b and 19 did not violate Lipinski's rule of five. In silico studies showed that these derivatives have a low blood-brain barrier penetration capability and high intestinal absorption. Taken together, derivatives 6b and 19 could serve as potential anticancer agents and merit further investigations.

Recyclable Magnetic Cu-MOF-74-Catalyzed C(sp2)-N Coupling and Cyclization under Microwave Irradiation: Synthesis of Imidazo[1,2-c]quinazolines and Their Analogues

Magnetic Cu-MOF-74 (Fe₃O₄@SiO₂@Cu-MOF-74) was synthesized for the first time by grafting MOF-74 (copper as the metal center) on the surface of core-shell magnetic carboxyl-functionalized silica gel (Fe₃O₄@SiO₂-COOH), which was prepared by coating core Fe₃O₄ nanoparticles with hydrolyzed 2-(3-(triethoxysilyl)propyl)succinic anhydride and tetraethyl orthosilicate. The structure of Fe₃O₄@SiO₂@Cu-MOF-74 nanoparticles was characterized by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and transmission electron microscopy (TEM). The prepared Fe₃O₄@SiO₂@Cu-MOF-74 nanoparticles could be applied as a recyclable catalyst to the synthesis of N-fused hybrid scaffolds. 2-(2-Bromoaryl)imidazoles and 2-(2-bromovinyl)imidazoles were coupled and cyclized with cyanamide in DMF in the presence of a catalytic amount of Fe₃O₄@SiO₂@Cu-MOF-74 along with a base to give imidazo[1,2-c]quinazolines and imidazo[1,2-c]pyrimidines, respectively, in good yields. The Fe₃O₄@SiO₂@Cu-MOF-74 catalyst could be easily recovered by a super magnetic bar and recycled more than four times while almost maintaining catalytic activity.

In silico study of HASDI (high-affinity selective DNA intercalator) as a new agent capable of highly selective recognition of the DNA sequence

Cancer as an acquired genetic disease is based on changes both in the genome itself and in transcription processes. Accordingly, it is at the DNA level that it makes sense to search for and design agents capable of effective and selective anticancer action. In this study, we used an iterative approach based on a molecular dynamics simulation to design a highly selective DNA-intercalating agent called HASDI. To confirm its selective affinity to DNA, we conducted two simulation experiments: HASDI in a complex with a DNA fragment of the EBNA1 gene (it targets 16 nucleotide pairs of this gene) and HASDI in a complex with a random DNA fragment of the KCNH2 gene. The molecular dynamics simulation was carried out in the GROMACS 2019 package. The binding energy was calculated by gmx_MMPBSA 1.5.2. The further analysis was performed using the built-in utilities of GROMACS, gmx_MMPBSA and also XMGRACE and Pymol 1.8. As a result, we determined that the EBNA1-50nt/HASDI complex was stable throughout the whole simulation trajectory. HASDI, due to the presence of a linker modified depending on a specific pair of nitrogenous bases, formed an average of 32 hydrogen bonds with a sequence of 16 nucleotide pairs. Phenazine rings were stably intercalated every 2 base pairs. The root-mean-square deviation of HASDI in such a complex fluctuated around the value of 6.5 Å and had no tendency to increase. The calculated value of the binding free energy was - 235.3 ± 7.77 kcal/mol. The KCNH2-50nt/HASDI complex, as an example of the intercalation of the designed structure into a random part of the human genome, maintained the stability of its position at a level comparable to the EBNA1-50nt/HASDI complex. The phenazine rings were constantly intercalated in their original positions, and the root-mean-square deviation fluctuated around one value, although it had a tendency to chaotic changes. At the same time, this complex was characterized by 17-19 hydrogen bonds, on average, and the binding free energy was - 193.47 ± 14.09 kcal/mol. Moreover, the DNA duplex had local single-nucleotide melting in the region of the 4th linker. According to a significant decrease in the number of hydrogen bonds, a decrease in energy gain, as well as a decrease in the stability of the DNA duplex characteristic of the KCNH2-50nt/HASDI complex compared to the target EBNA1-50nt/HASDI complex, the molecule we designed can be considered a potentially selective DNA polyintercalating agent capable of relatively accurate recognition of 16 base pairs.

3-Aryl-5-aminobiphenyl Substituted [1,2,4]triazolo[4,3-c]quinazolines: Synthesis and Photophysical Properties

Amino-[1,1']-biphenyl-containing 3-aryl-[1,2,4]triazolo[4,3-c]quinazoline derivatives with fluorescent properties have been designed and synthesized. The type of annelation of the triazole ring to the pyrimidine one has been unambiguously confirmed by means of an X-ray diffraction (XRD) method; the molecules are non-planar, and the aryl substituents form the pincer-like conformation. The UV/Vis and photoluminescent properties of target compounds were investigated in two solvents of different polarities and in a solid state. The samples emit a broad range of wavelengths and display fluorescent quantum yields of up to 94% in toluene solutions. 5-(4'-Diphenylamino-[1,1']-biphenyl-4-yl)-3-(4-(trifluoromethyl)phenyl)-[1,2,4]triazolo[4,3-c]quinazoline exhibits the strongest emission in toluene and a solid state. Additionally, the solvatochromic properties were studied for the substituted [1,2,4]triazolo[4,3-c]quinazolines. Moreover, the changes in absorption and emission spectra have been demonstrated upon the addition of water to MeCN solutions, which confirms aggregate formation, and some samples were found to exhibit aggregation-induced emission enhancement. Further, the ability of triazoloquinazolines to detect trifluoroacetic acid has been analyzed; the presence of TFA induces changes in both absorption and emission spectra, and acidochromic behavvior was observed for some triazoloquinazoline compounds. Finally, electronic-structure calculations with the use of quantum-chemistry methods were performed for synthesized compounds.

New [1,2,4]triazolo[4,3-c]quinazolines as intercalative Topo II inhibitors: Design, synthesis, biological evaluation, and in silico studies

Fifteen quinazoline derivatives were designed and synthesized as DNA intercalators. The cytotoxicity of the designed members was assessed against HCT-116 and HepG2 cancer cell lines. In addition, the topoisomerase II (Topo II) inhibitory effect was assessed. Compound 16 was the most cytotoxic and Topo II inhibitor with low cytotoxicity against Vero cells. Compounds 16, 17, and 18 showed significant DNA binding affinities. Compound 16 showed Topo II catalytic inhibitory effect at a concentration of 10 μM. Further mechanistic investigations revealed the capability of compound 16 to induce apoptosis in HCT-116 cells and arrest the growth at the S and G2/M phases. Also, compound 16 showed a significant increase in the level of BAX (2.18-fold) and a marked decrease in the level of Bcl-2 (1.9-fold) compared to the control cells. In silico studies revealed the ability of the synthesized members to bind to the DNA-Topo II complex.

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.

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.

Synthesis, biological evaluation, and molecular docking of new series of antitumor and apoptosis inducers designed as VEGFR-2 inhibitors

Based on quinazoline, quinoxaline, and nitrobenzene scaffolds and on pharmacophoric features of VEGFR-2 inhibitors, 17 novel compounds were designed and synthesised. VEGFR-2 IC50 values ranged from 60.00 to 123.85 nM for the new derivatives compared to 54.00 nM for sorafenib. Compounds 15a, 15b, and 15d showed IC50 from 17.39 to 47.10 µM against human cancer cell lines; hepatocellular carcinoma (HepG2), prostate cancer (PC3), and breast cancer (MCF-7). Meanwhile, the first in terms of VEGFR-2 inhibition was compound 15d which came second with regard to antitumor assay with IC50 = 24.10, 40.90, and 33.40 µM against aforementioned cell lines, respectively. Furthermore, Compound 15d increased apoptosis rate of HepG2 from 1.20 to 12.46% as it significantly increased levels of Caspase-3, BAX, and P53 from 49.6274, 40.62, and 42.84 to 561.427, 395.04, and 415.027 pg/mL, respectively. Moreover, 15d showed IC50 of 253 and 381 nM against HER2 and FGFR, respectively.

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.

Discovery of new 1H-pyrazolo[3,4-d]pyrimidine derivatives as anticancer agents targeting EGFRWT and EGFRT790M

New 1H-pyrazolo[3,4-d]pyrimidine derivatives were designed and synthesised to act as epidermal growth factor receptor inhibitors (EGFRIs). The synthesised derivatives were assessed for their in vitro anti-proliferative activities against A549 and HCT-116 cancer cells. Compounds 8, 10, 12a, and 12b showed potent anti-proliferative activities. Compound 12b was the most promising member with IC50 values of 8.21 and 19.56 µM against A549 and HCT-116, respectively. Compounds 8, 10, 12a, and 12b were evaluated for their kinase inhibitory activities against wild EGFR (EGFRWT). Compound 12b was the most potent member showing an IC50 value of 0.016 µM. In addition, compound 12b showed noticeable activity against mutant EGFR (EGFRT790M) (IC50 = 0.236 µM). Flow cytometric analyses revealed that compound 12b is a good apoptotic inducer and can arrest the cell cycle at S and G2/M phases. Furthermore, it produced an 8.8-fold increase in BAX/Bcl-2 ratio. Molecular docking studies were carried out against EGFRWT and EGFRT790M.

The Discovery of Potential SARS-CoV-2 Natural Inhibitors among 4924 African Metabolites Targeting the Papain-like Protease: A Multi-Phase In Silico Approach

Four compounds, hippacine, 4,2'-dihydroxy-4'-methoxychalcone, 2',5'-dihydroxy-4-methoxychalcone, and wighteone, were selected from 4924 African natural metabolites as potential inhibitors against SARS-CoV-2 papain-like protease (PLpro, PDB ID: 3E9S). A multi-phased in silico approach was employed to select the most similar metabolites to the co-crystallized ligand (TTT) of the PLpro through molecular fingerprints and structural similarity studies. Followingly, to examine the binding of the selected metabolites with the PLpro (molecular docking. Further, to confirm this binding through molecular dynamics simulations. Finally, in silico ADMET and toxicity studies were carried out to prefer the most convenient compounds and their drug-likeness. The obtained results could be a weapon in the battle against COVID-19 via more in vitro and in vivo studies.

Structure-Based Virtual Screening, Docking, ADMET, Molecular Dynamics, and MM-PBSA Calculations for the Discovery of Potential Natural SARS-CoV-2 Helicase Inhibitors from the Traditional Chinese Medicine

Continuing our antecedent work against COVID-19, a set of 5956 compounds of traditional Chinese medicine have been virtually screened for their potential against SARS-CoV-2 helicase (PDB ID: 5RMM). Initially, a fingerprint study with VXG, the ligand of the target enzyme, disclosed the similarity of 187 compounds. Then, a molecular similarity study declared the most similar 40 compounds. Subsequently, molecular docking studies were carried out to examine the binding modes and energies. Then, the most appropriate 26 compounds were subjected to in silico ADMET and toxicity studies to select the most convenient inhibitors to be: (1R,2S)-ephedrine (57), (1R,2S)-norephedrine (59), 2-(4-(pyrrolidin-1-yl)phenyl)acetic acid (84), 1-phenylpropane-1,2-dione (195), 2-methoxycinnamic acid (246), 2-methoxybenzoic acid (364), (R)-2-((R)-5-oxopyrrolidin-3-yl)-2-phenylacetic acid (405), (Z)-6-(3-hydroxy-4-methoxystyryl)-4-methoxy-2H-pyran-2-one (533), 8-chloro-2-(2-phenylethyl)-5,6,7-trihydroxy-5,6,7,8-tetrahydrochromone (637), 3-((1R,2S)-2-(dimethylamino)-1-hydroxypropyl)phenol (818), (R)-2-ethyl-4-(1-hydroxy-2-(methylamino)ethyl)phenol (5159), and (R)-2-((1S,2S,5S)-2-benzyl-5-hydroxy-4-methylcyclohex-3-en-1-yl)propane-1,2-diol (5168). Among the selected 12 compounds, the metabolites, compound 533 showed the best docking scores. Interestingly, the MD simulation studies for compound 533, the one with the highest docking score, over 100 ns showed its correct binding to SARS-CoV-2 helicase with low energy and optimum dynamics. Finally, MM-PBSA studies showed that 533 bonded favorably to SARS-CoV-2 helicase with a free energy value of −83 kJ/mol. Further, the free energy decomposition study determined the essential amino acid residues that contributed favorably to the binding process. The obtained results give a huge hope to find a cure for COVID-19 through further in vitro and in vivo studies for the selected compounds.

A Multistage In Silico Study of Natural Potential Inhibitors Targeting SARS-CoV-2 Main Protease

Among a group of 310 natural antiviral natural metabolites, our team identified three compounds as the most potent natural inhibitors against the SARS-CoV-2 main protease (PDB ID: 5R84), Mpro. The identified compounds are sattazolin and caprolactin A and B. A validated multistage in silico study was conducted using several techniques. First, the molecular structures of the selected metabolites were compared with that of GWS, the co-crystallized ligand of Mpro, in a structural similarity study. The aim of this study was to determine the thirty most similar metabolites (10%) that may bind to the Mpro similar to GWS. Then, molecular docking against Mpro and pharmacophore studies led to the choice of five metabolites that exhibited good binding modes against the Mpro and good fit values against the generated pharmacophore model. Among them, three metabolites were chosen according to ADMET studies. The most promising Mpro inhibitor was determined by toxicity and DFT studies to be caprolactin A (292). Finally, molecular dynamics (MD) simulation studies were performed for caprolactin A to confirm the obtained results and understand the thermodynamic characteristics of the binding. It is hoped that the accomplished results could represent a positive step in the battle against COVID-19 through further in vitro and in vivo studies on the selected 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.

DNA Intercalators as Anticancer Agents

Cancer is one of the most prevailing disease conditions which occurs due to uncontrolled cell division either due to natural mutation to the genes or due to changes induced by physical, chemical, or biological carcinogens. According to WHO, it is the second leading cause of death worldwide and has reported 10 million deaths in 2020. Hence there arises the need for better chemotherapies and DNA intercalators are one such emerging therapy for cancer. DNA intercalating agents reversibly intercalate with the double-helical structure of DNA by interacting with adjacent base pairs and disrupting the structure of DNA and thereby causing cell death. Here we discuss the different classes of organo-intercalators used in cancer therapy describing their anticancer and intercalation ability by different methods along with their structure-activity relationship and mechanism of action.

Multi-Step In Silico Discovery of Natural Drugs against COVID-19 Targeting Main Protease

In continuation of our antecedent work against COVID-19, three natural compounds, namely, Luteoside C (130), Kahalalide E (184), and Streptovaricin B (278) were determined as the most promising SARS-CoV-2 main protease (Mpro) inhibitors among 310 naturally originated antiviral compounds. This was performed via a multi-step in silico method. At first, a molecular structure similarity study was done with PRD_002214, the co-crystallized ligand of Mpro (PDB ID: 6LU7), and favored thirty compounds. Subsequently, the fingerprint study performed with respect to PRD_002214 resulted in the election of sixteen compounds (7, 128, 130, 156, 157, 158, 180, 184, 203, 204, 210, 237, 264, 276, 277, and 278). Then, results of molecular docking versus Mpro PDB ID: 6LU7 favored eight compounds (128, 130, 156, 180, 184, 203, 204, and 278) based on their binding affinities. Then, in silico toxicity studies were performed for the promising compounds and revealed that all of them have good toxicity profiles. Finally, molecular dynamic (MD) simulation experiments were carried out for compounds 130, 184, and 278, which exhibited the best binding modes against Mpro. MD tests revealed that luteoside C (130) has the greatest potential to inhibit SARS-CoV-2 main protease.

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.

Design, synthesis, and SAR studies of novel 4-methoxyphenyl pyrazole and pyrimidine derivatives as potential dual tyrosine kinase inhibitors targeting both EGFR and VEGFR-2

Guided by the pharmacophoric features of both EGFR and VEGFR-2 antagonists, two novel series of 4-methoxyphenyl pyrazole and pyrimidine derivatives [(4a-c) and (5a-c, 6, 7a-c, 8, 9, 10, 11a,c, 12, 13a-c, 14a-c, and 15a,b)], respectively, were designed and synthesized as dual EGFR/VEGFR-2 inhibitors. Interestingly, compound 12 showed very strong antiproliferative effects towards all the five studied cell lines (HepG-2, MCF-7, MDA-231, HCT-116, and Caco-2) with IC₅₀ values of 3.74, 7.81, 4.85, 2.96, and 9.27 µM, respectively. Also, it achieved the highest inhibitory activities against both EGFR and VEGFR-2 as well (IC₅₀ = 0.071 and 0.098 µM) compared to the two reference drugs, erlotinib (IC₅₀ = 0.063 µM) and sorafenib (IC₅₀ = 0.041 µM), respectively. Moreover, four compounds (4a, 7a, 7c, and 12) were selected for further evaluation through cell cycle analysis and Annexin V-based flow cytometry assay in the HepG-2 cell line. In addition, deep computational studies including molecular docking, physicochemical properties, profiling pharmacokinetics, ADMET studies, and toxicity predictions were performed for the designed compounds to evaluate the prospective drug candidates. Finally, analyzing the structure-activity relationship (SAR) of the new derivatives gives us a lot of interesting promising results which could help medicinal chemists to design more potent drug candidates soon as well.

Triazoloquinazoline derived classical DNA intercalators: Design, synthesis, in silico ADME profile, docking, and antiproliferative evaluations

Thirteen novel [1,2,4]triazolo[4,3-c]quinazoline derivatives as DNA intercalators were synthesized and their anticancer activities evaluated against HepG2 and HCT-116 cells. A docking study was carried out to explore how the new derivatives bind to active sites of DNA. The docking data were highly interrelated with that of biological testing. The HCT-116 cell line was the most sensitive one to the effect of the new derivatives. Compound 7_c exhibited the highest anticancer activities against both the HepG2 and HCT116 cancer cell lines. Despite this compound displaying less activity than doxorubicin, it could be useful as a template for future manipulation, optimization, and investigation to produce other analogs with potential activity. The most active derivatives, 7_c , 7_b , and 7_a were evaluated as DNA binders. Compound 7_c displayed the highest binding affinity. Furthermore, the absorption, distribution, metabolism, excretion, and toxicity (ADMET) profile was calculated for the four most active compounds in comparison to doxorubicin as reference drug. Our derivatives 7_a , 7_b , and 7_c displayed a very good calculated ADMET profile in comparison to doxorubicin.

Multi-Phase In Silico Discovery of Potential SARS-CoV-2 RNA-Dependent RNA Polymerase Inhibitors among 3009 Clinical and FDA-Approved Related Drugs

Proceeding our prior studies of SARS-CoV-2, the inhibitory potential against SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) has been investigated for a collection of 3009 clinical and FDA-approved drugs. A multi-phase in silico approach has been employed in this study. Initially, a molecular fingerprint experiment of Remdesivir (RTP), the co-crystallized ligand of the examined protein, revealed the most similar 150 compounds. Among them, 30 compounds were selected after a structure similarity experiment. Subsequently, the most similar 30 compounds were docked against SARS-CoV-2 RNA-dependent RNA polymerase (PDB ID: 7BV2). Aloin 359, Baicalin 456, Cefadroxil 1273, Sophoricoside 1459, Hyperoside 2109, and Vitexin 2286 exhibited the most precise binding modes, as well as the best binding energies. To confirm the obtained results, MD simulations experiments have been conducted for Hyperoside 2109, the natural flavonoid glycoside that exhibited the best docking scores, against RdRp (PDB ID: 7BV2) for 100 ns. The achieved results authenticated the correct binding of 2109, showing low energy and optimum dynamics. Our team presents these outcomes for scientists all over the world to advance in vitro and in vivo examinations against COVID-19 for the promising compounds.

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.

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.

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.

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.

In Silico Screening of Semi-Synthesized Compounds as Potential Inhibitors for SARS-CoV-2 Papain-like Protease: Pharmacophoric Features, Molecular Docking, ADMET, Toxicity and DFT Studies

Papain-like protease is an essential enzyme in the proteolytic processing required for the replication of SARS-CoV-2. Accordingly, such an enzyme is an important target for the development of anti-SARS-CoV-2 agents which may reduce the mortality associated with outbreaks of SARS-CoV-2. A set of 69 semi-synthesized molecules that exhibited the structural features of SARS-CoV-2 papain-like protease inhibitors (PLPI) were docked against the coronavirus papain-like protease (PLpro) enzyme (PDB ID: (4OW0). Docking studies showed that derivatives 34 and 58 were better than the co-crystallized ligand while derivatives 17, 28, 31, 40, 41, 43, 47, 54, and 65 exhibited good binding modes and binding free energies. The pharmacokinetic profiling study was conducted according to the four principles of the Lipinski rules and excluded derivative 31. Furthermore, ADMET and toxicity studies showed that derivatives 28, 34, and 47 have the potential to be drugs and have been demonstrated as safe when assessed via seven toxicity models. Finally, comparing the molecular orbital energies and the molecular electrostatic potential maps of 28, 34, and 47 against the co-crystallized ligand in a DFT study indicated that 28 is the most promising candidate to interact with the target receptor (PLpro).

In Silico Exploration of Potential Natural Inhibitors against SARS-Cov-2 nsp10

In continuation of our previous effort, different in silico selection methods were applied to 310 naturally isolated metabolites that exhibited antiviral potentialities before. The applied selection methods aimed to pick the most relevant inhibitor of SARS-CoV-2 nsp10. At first, a structural similarity study against the co-crystallized ligand, S-Adenosyl Methionine (SAM), of SARS-CoV-2 nonstructural protein (nsp10) (PDB ID: 6W4H) was carried out. The similarity analysis culled 30 candidates. Secondly, a fingerprint study against SAM preferred compounds 44, 48, 85, 102, 105, 182, 220, 221, 282, 284, 285, 301, and 302. The docking studies picked 48, 182, 220, 221, and 284. While the ADMET analysis expected the likeness of the five candidates to be drugs, the toxicity study preferred compounds 48 and 182. Finally, a density-functional theory (DFT) study suggested vidarabine (182) to be the most relevant SARS-Cov-2 nsp10 inhibitor.

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.

Evaluation of Synthetic 2,4-Disubstituted-benzo[g]quinoxaline Derivatives as Potential Anticancer Agents

A new series of 2,4-disubstituted benzo[g]quinoxaline molecules have been synthesized, using naphthalene-2,3-diamine and 1,4-dibromonaphthalene-2,3-diamine as the key starting materials. The structures of the new compounds were confirmed by spectral data along with elemental microanalyses. The cytotoxic activity of all synthesized benzo[g]quinoxaline derivatives was assessed in vitro against the breast MCF-7 cancer cell line. The tested molecules revealed good cytotoxicity toward the breast MCF-7 cancer cell line, especially compound 3. The results of topoisomerase IIβ inhibition assay revealed that compound 3 exhibits potent inhibitory activity in submicromolar concentration. Additionally, compound 3 was found to cause pre-G1 apoptosis, and slightly increase the cell population at G1 and S phases of the cell cycle profile in MCF-7 cells. Finally, compound 3 induces apoptosis via Bax activation and downregulation of Bcl2, as revealed by ELISA assay.

An overview of triazoloquinazolines: Pharmacological significance and recent developments

Nitrogen heterocyclic rings have participated to constitute most of the drugs and several pharmacologically related compounds. The existence of such hetero atoms/groups in heterocyclic systems privileged specificities in their biological objectives. Particularly, quinazoline and triazole are biologically imperative platforms known to be linked with various pharmacological activities. Some of the prominent pharmacological responses ascribed to these systems are analgesic, antiinflammatory, anticonvulsant, hypnotic, antihistaminic, antihypertensive, anticancer, antimicrobial, antitubercular, antiviral and antimalarial activities. This diversity in the pharmacological outputs for both triazole and quinazoline systems has encouraged the medicinal chemistry researchers to create several chemical routes aiming at the incorporation of two rings in one molecule named triazoloquinazoline system. This system has shown multiple potential activities against numerous targets. Correlation the specific structural features of triazoloquinazoline system with its pharmacological purposes has successively been achieved by performing several pharmacological examinations and structure-activity relationship studies. The development of triazoloquinazoline derivatives and the understanding of their pharmacological targets offer opportunities for novel therapeutics. This review mainly emphases on the medicinal chemistry aspects of triazoloquinazolines including synthesis, reactivity, biological activity and structure activity relationship studies (SARs). Moreover, this review collates literature reported by researchers on triazoquinazolines and provides detailed attention on their analogs pharmacological activities in the perspective of drug development and discovery.

Design, synthesis, molecular docking and in silico ADMET profile of pyrano[2,3-d]pyrimidine derivatives as antimicrobial and anticancer agents

Pyrano[2,3-d]pyrimidine derivatives were synthesized by treating cyclic compounds containing active methylene group with aldehyde and malononitrile in butanol. The behavior of pyrano[2,3-d]pyrimidine towards some electrophlies namely triethylorthoformate followed by nitrogen nucleophiles as isobutylamine, urea, phenylthiourea, p-toluidine, o-phenylenediamine, o-aminophenol, 2-amino-4-methyl-pyridine and acetic acid with the aim of obtaining some interesting non-mixed heterocyclic compounds. All synthesized compounds to some extent have shown good antimicrobial activity against different microbial strains that had been extracted by inhibiting cell wall synthesis. Compound 5b showed the highest antibacterial activities against B. subtilis, S. aureus and E. coli. On the other hand compound 5 g exhibited the highest antibacterial and antifungal activities against P. aeruginosa and A. niger respectively. In addition, they explore cytotoxic potentialities against different cell lines via DNA intercalation and Top-II inhibition. The cytotoxic activities clarify the strong inhibitory activity of derivative 5a against HepG2 cells with IC₅₀ = 2.09 μM, while HCT-116 cells were highly susceptible to derivative 5c with IC₅₀ = 2.61 μM, in the meantime, derivative 5f showed pronounced negative impact against MCF-7 (IC₅₀ = 2.43 μM) when compared with other prepared compounds. All derivatives exhibited higher anticancer activities than doxorubicin against the three cell lines except compound 2 against both HepG2 and MCF-7 and compound 5e against HepG2 cell lines. Compounds 5a, 5c and 5f potently intercalate DNA at IC₅₀ values of 26.96, 27.13 and 29.86 µM respectively, which were more potent than doxorubicin (IC₅₀ value of 31.27 µM). Moreover, compounds 5a, 5c and 5f exhibited very good Topoisomerase II inhibitory activities with IC₅₀ values of 0.752, 0.791 and 0.776 µM respectively, that were more potent than that of doxorubicin (IC₅₀ = 0.94 µM). For a great extent, the molecular modeling studies were in agreement with that of in vitro cytotoxicity activity, DNA binding and Top-II inhibition results.

Anticancer activity of pyrimidodiazepines based on 2-chloro-4-anilinoquinazoline: synthesis, DNA binding and molecular docking

Multidrug resistance to chemotherapy is a critical health problem associated with mutation of the therapeutic target. Therefore, the development of anticancer agents remains a challenge to overcome cancer cell resistance. Herein, a new series of quinazoline-based pyrimidodiazepines 16a-g were synthesized by the cyclocondensation reaction of 2-chloro-4-anilinoquinazoline-chalcones 14a-g with 2,4,5,6-tetraaminopyrimidine. All quinazoline derivatives 14a-g and 16a-g were selected by the U.S. National Cancer Institute (NCI) for testing their anticancer activity against 60 cancer cell lines of different panels of human tumors. Among the tested compounds, quinazoline-chalcone 14g displayed high antiproliferative activity with GI₅₀ values between 0.622-1.81 μM against K-562 (leukemia), RPMI-8226 (leukemia), HCT-116 (colon cancer) LOX IMVI (melanoma), and MCF7 (breast cancer) cancer cell lines. Additionally, the pyrimidodiazepines 16a and 16c exhibited high cytostatic (TGI) and cytotoxic activity (LC₅₀), where 16c showed high cytotoxic activity, which was 10.0-fold higher than the standard anticancer agent adriamycin/doxorubicin against ten cancer cell lines. COMPARE analysis revealed that 16c may possess a mechanism of action through DNA binding that is similar to that of CCNU (lomustine). DNA binding studies indicated that 14g and 16c interact with the calf thymus DNA by intercalation and groove binding, respectively. Compounds 14g, 16c and 16a displayed strong binding affinities to DNA, EGFR and VEGFR-2 receptors. None of the active compounds showed cytotoxicity against human red blood cells.

Design, synthesis, docking, ADMET profile, and anticancer evaluations of novel thiazolidine-2,4-dione derivatives as VEGFR-2 inhibitors

The anticancer activity of novel thiazolidine-2,4-diones was evaluated against HepG2, HCT-116, and MCF-7 cells. Among the tested cancer cell lines, HCT-116 was the most sensitive one to the cytotoxic effect of the new derivatives. In particular, compounds 18, 11, and 10 were found to be the most potent derivatives among all the tested compounds against the HepG2, HCT-116, and MCF-7 cancer cell lines, with IC₅₀ values ranging from 38.76 to 53.99 µM. The most active antiproliferative derivatives (7-14 and 15-19) were subjected to further biological studies to evaluate their inhibitory potentials against VEGFR-2. The tested compounds displayed a good-to-medium inhibitory activity, with IC₅₀ values ranging from 0.26 to 0.72 µM. Among them, compounds 18, 11, and 10 potently inhibited VEGFR-2 at IC₅₀ values in the range of 0.26-0.29 µM, which are nearly three times that of the sorafenib IC₅₀ value (0.10 µM). Although our derivatives showed lower activities than the reference drug, they could be useful as a template for future design, optimization, adaptation, and investigation to produce more potent and selective VEGFR-2 inhibitors with higher anticancer analogs. The ADMET profile showed that compounds 18, 11, and 10 do not violate any of Lipinski's rules and have a comparable intestinal absorptivity in humans. Also, the new derivatives could not inhibit cytochrome P3A4. Unlike sorafenib and doxorubicin, compounds 18, 11, and 10 are expected to have prolonged dosing intervals. Moreover, compounds 10 and 18 displayed a wide therapeutic index and higher selectivity against cancer cells as compared with their cytotoxicity against normal cells.

New quinoxaline-2(1H)-ones as potential VEGFR-2 inhibitors: design, synthesis, molecular docking, ADMET profile and anti-proliferative evaluations

Eleven new quinoxaline derivatives were designed and synthesized as modified VEGFR-2 inhibitors of our previous work.