Amination of the 2-aryl-6-bromo-4-chloro-8-iodoquinazolines with 2-aminoethanol followed by acid-promoted cyclodehydration of the incipient 2-((6,8-dihalo-2-phenylquinazolin-4-yl)amino)ethanols afforded the corresponding novel 5-aryl-9-bromo-7-iodo-2,3-dihydro-2H-imidazo[1,2-c]quinazolines. The latter were, in turn, subjected to sequential (Sonogashira and Suzuki-Miyaura) and one-pot two-step (Sonogashira/Stille) cross-coupling reactions to afford diversely functionalized polycarbo-substituted 2H-imidazo[1,2-c]quinazolines. The imidazoquinazolines were screened for in vitro cytotoxicity against human breast adenocarcinoma (MCF-7) cells and human cervical cancer (HeLa) cells.

From three previously identified antiplasmodial hit compounds (A-C) and inactive series (D), all based on a 2-trichloromethylquinazoline scaffold, we conducted a structure-activity relationship (SAR) study at position four of the quinazoline ring by synthesizing 42 novel derivatives bearing either a carboxamido- or an alkoxy-group, to identify antiplasmodial compounds and to enrich the knowledge about the 2-trichloromethylquinazoline antiplasmodial pharmacophore. All compounds were evaluated in vitro for their cytotoxicity towards the HepG2 cell line and their activity against the multiresistant K1 P. falciparum strain, using doxorubicin, chloroquine and doxycycline as reference drugs. Four hit-compounds (EC50 K1 P. falciparum ≤ 2 µM and SI ≥ 20) were identified among 4-carboxamido derivatives (2, 9, 16, and 24) and two among 4-alkoxy derivatives (41 and 44). Regarding the two most potent molecules (16 and 41), five derivatives without a 2-CCl3 group were prepared, evaluated, and appeared totally inactive (EC50 > 50 µM), showing that the 2-trichloromethyl group was mandatory for the antiplasmodial activity.

A series of novel 2,4-disubstituted quinazolines were synthesized and evaluated for their anti-tumor activity against five human cancer cells (MDA-MB-231, MCF-7, PC-3, HGC-27 and MGC-803) using MTT assay. Among them, compound 9n showed the most potent cytotoxicity against breast cancer cells. Compound 9n also significantly inhibited the colony formation and migration of MDA-MB-231 and MCF-7 cells. Meanwhile, compound 9n induced cell cycle arrest at G1 phase and cell apoptosis, as well as increased accumulation of intracellular ROS. Furthermore, compound 9n exerted anti-tumor effects in vitro via decreasing the expression of anti-apoptotic protein Bcl-2 and increasing the pro-apoptotic protein Bax and p53. Mechanistically, compound 9n markedly decreased p-EGFR and p-PI3K expression, which revealed that compound 9n targeted breast cancer cells via interfering with EGFR-PI3K signaling pathway. Molecular docking suggested that compound 9n could indeed bind into the active pocket of EGFR. All the findings suggest that compound 9n might be a valuable lead compound for anti-tumor agents targeting breast cancer cells.

A new series of pyrrolo[3,4-h]quinazolines was conveniently prepared with a broad substitution pattern. A large number of derivatives was obtained and the cellular cytotoxicity was evaluated in vitro against 5 different human tumor cell lines with GI₅₀ values reaching the low micromolar level (1.3-19.8 μM). These compounds were able to induce cell death mainly by apoptosis through a mitochondrial dependent pathway. Selected compounds showed antimitotic activity and a reduction of tubulin polymerization in a concentration-dependent manner. Moreover, they showed anti-angiogenic properties since reduced in vitro endothelial cell migration and disrupted HUVEC capillary-like tube network in Matrigel.

Because of its involvement in the progression of several malignant tumors, the histone lysine-specific demethylase 1 (LSD1) has become a prominent drug target in modern medicinal chemistry research. We report on the discovery of two classes of noncovalent inhibitors displaying unique structural features. The antibiotics polymyxins bind at the entrance of the substrate cleft, where their highly charged cyclic moiety interacts with a cluster of positively charged amino acids. The same site is occupied by quinazoline-based compounds, which were found to inhibit the enzyme through a most peculiar mode because they form a pile of five to seven molecules that obstruct access to the active center. These data significantly indicate unpredictable strategies for the development of epigenetic inhibitors.

Synthetic methods used to generate substituted anilines and quinazolines, both privileged pharmacological structures, are cumbersome, hazardous or, in some cases, unavailable. We developed a straightforward method for making isatoic anhydride-8-amide from isatin-7-carboxylic acid as a tool to easily produce a range of quinazoline and substituted aniline derivatives using adaptable pH-sensitive cyclization chemistry. The approaches are inexpensive, simple, fast, efficient at room temperature and scalable, enabling the synthesis of both established and new quinazolines and also highly substituted anilines including cyano derivatives.

Herein, we describe the synthesis of novel unsymmetrical polycarbo-substituted 4-anilinoquinazolines derived from the 2-aryl-6-bromo-8-iodoquinazolines via one-pot three-step reaction sequences involving initial amination and subsequent double cross-coupling (bis-Suzuki, Sonogashira/Stille or Sonogashira/Suzuki-Miyaura) reactions with different cross coupling partners for the two carbon-carbon bond formation steps. The 4-anilinoquinazolines were evaluated for potential cytotoxicity against three cancer cell lines, namely, human breast adenocarcinoma (MCF-7) cells, human cervical cancer (HeLa) and human lung cancer (A549) cells. The most active compounds, 2b, 2c, 3c, 4a, 4c and 5a, were found to be more selective against the MCF-7 and HeLa cell lines than the human lung carcinoma (A549) cells. We selected compounds 2c, 3c and 7a as representatives for further evaluation for potential to induce apoptosis and/or necrotic properties in the three cancer cell lines. Compound 2c induced apoptosis of MCF-7 cells through cell membrane alteration. Treatment of Hela and A549 cell lines with compounds 3c and 7a, respectively, led to caspase-3 activation in both cell lines. Compound 3c, on the other hand, caused more necrosis than apoptosis induction in the membrane alteration assay.

A type of novel 4,6-substituted-(diaphenylamino)quinazolines, which designed based on the 4-(phenylamino)quinazoline moiety, have been discovered as potential EGFR inhibitors. These compounds displayed good antiproliferative activity and EGFR-TK inhibitory activity. Especially, 4-((4-(3-bromophenylamino)quinazolin-6-ylamino)methyl)phenol (5b), showed the most potent inhibitory activity (IC(50)=0.28μM for Hep G2, IC(50)=0.59μM for A16-F10 and IC(50)=0.87μM for EGFR) and effectively induces apoptosis in a dose-dependent manner in the Hep G2 cell line. Molecular docking of 5b into EGFR TK active site was also performed. This inhibitor nicely fitting the active site might well explain its excellent inhibitory activity.

Synthesis of hydrazones (1a-4a and 1b-4b), quinazolines (3c·MeOH and 3d·MeOH), and hydrazone-Schiff bases (4c and 4d) is achieved by combining suitable aldehydes (2,3- or 2,4-dihydroxybenzaldehyde) with four hydrazides (isonicotinic, nicotinic, and 2- or 4-aminobenzoic acid hydrazide). A suite of approaches for their preparation is described: solution-based synthesis, mechanosynthesis, and solid-state melt reactions. The mechanochemical approach is generally a better choice for the quinazolines, while the solid-state melt reaction is more efficient for derivatives of (iso)nicotinic based hydrazones. Crystalline amine-functionalised hydrazones 4a and 4b undergo post-synthetic modifications in reactions with 3- or 4-pyridinecarbaldehyde vapours to form hydrazone-Schiff bases 4a-3py, 4b-3py, 4a-4py, and 4b-4py. Mechanochemical and vapour-mediated reactions are followed by ex situ powder X-ray diffraction and IR-ATR methods, respectively. The chemometric analysis of these data using principal component analysis provided an insight into the reaction profiles and reaction times. Azines (5a and 5b), achieved from aldehydes and hydrazine, reversibly change colour in response to temperature changes. The structures of all products are ascertained by a combined use of spectroscopic and X-ray diffraction methods. The cytotoxic and antimicrobial activities of all compounds against selected human cancer cell lines and bacterial strains are evaluated.

Deregulation of the receptor tyrosine kinase RET has been implicated in medullary thyroid cancer, a small percentage of lung adenocarcinomas, endocrine-resistant breast cancer and pancreatic cancer. There are several clinically approved multi-kinase inhibitors that target RET as a secondary pharmacology but additional activities, most notably inhibition of KDR, lead to dose-limiting toxicities. There is, therefore, a clinical need for more specific RET kinase inhibitors. Herein we report our efforts towards identifying a potent and selective RET inhibitor using vandetanib 1 as the starting point for structure-based drug design. Phenolic anilinoquinazolines exemplified by 6 showed improved affinities towards RET but, unsurprisingly, suffered from high metabolic clearance. Efforts to mitigate the metabolic liability of the phenol led to the discovery that a flanking substituent not only improved the hepatocyte stability, but could also impart a significant gain in selectivity. This culminated in the identification of 36; a potent RET inhibitor with much improved selectivity against KDR.

New pyrido[3,4-g]quinazoline derivatives were prepared and evaluated for their inhibitory potency toward 5 protein kinases (CLK1, DYRK1A, GSK3, CDK5, CK1). A related pyrido[4,3-h]quinazoline scaffold with an angular structure was also synthesized and its potency against the same protein kinase panel was compared to the analogous pyrido[3,4-g]quinazoline. Best results were obtained for 10-nitropyrido[3,4-g]quinazoline 4 toward CLK1 with nanomolar activities.

The ineffectiveness and failing of chemotherapeutic treatments are often associated with multidrug resistance (MDR). MDR is primarily linked to the overexpression of ATP-binding cassette (ABC) transporter proteins in cancer cells. ABCG2 (ATP-binding cassette subfamily G member 2, also known as the breast cancer resistance protein (BCRP)) mediates MDR by an increased drug efflux from the cancer cells. Therefore, the inhibition of ABCG2 activity during chemotherapy ought to improve the efficacy of the administered anti-cancer agents by reversing MDR or by enhancing the agents' pharmacokinetic properties. Significant efforts have been made to develop novel, powerful, selective, and non-toxic inhibitors of BCRP. However, thus far the clinical relevance of BCRP-selective MDR-reversal has been unsuccessful, due to either adverse drug reactions or significant toxicities in vivo. We here report a facile access towards carboranyl quinazoline-based inhibitors of ABCG2. We determined the influence of different methoxy-substitution patterns on the 2-phenylquinazoline scaffold in combination with the beneficial properties of an incorporated inorganic carborane moiety. A series of eight compounds was synthesized and their inhibitory effect on the ABCG2-mediated Hoechst transport was evaluated. Molecular docking studies were performed to better understand the structure-protein interactions of the novel inhibitors, exhibiting putative binding modes within the inner binding site. Further, the most potent, non-toxic compounds were investigated for their potential to reverse ABCG2-mediated mitoxantrone (MXN) resistance. Of these five evaluated compounds, N-(closo-1,7-dicarbadodecaboran(12)-9-yl)-6,7-dimethoxy-2-(3,4,5-trimethoxyphenyl)-quinazolin-4-amine (DMQCd) exhibited the strongest inhibitory effect towards ABCG2 in the lower nanomolar ranges. Additionally, DMQCd was able to reverse BCRP-mediated MDR, making it a promising candidate for further research on hybrid inorganic-organic compounds.

Mortality and morbidity caused by viruses are a global health problems. Therefore, there is always a need to create novel therapeutic agents and refine existing ones to maximize their efficacy. Our lab has produced benzoquinazolines derivatives that have proven effective activity as antiviral compounds against herpes simplex (HSV 1 and 2), coxsackievirus B4 (CVB4), and hepatitis viruses (HAV and HCV). This in vitro study was aimed at investigating the effectiveness of benzoquinazoline derivatives 1-16 against adenovirus type 7 and bacteriophage phiX174 using a plaque assay. The cytotoxicity against adenovirus type 7 was also performed in vitro, using a MTT assay. Most of the compounds exhibited antiviral activity against bacteriophage phiX174. However, compounds 1, 3, 9, and 11 showed statistically significant reductions of 60-70% against bacteriophage phiX174. By contrast, compounds 3, 5, 7, 12, 13, and 15 were ineffective against adenovirus type 7, and compounds 6 and 16 had remarkable efficacy (50%). Using the MOE-Site Finder Module, a docking study was carried out in order to create a prediction regarding the orientation of the lead compounds (1, 9, and 11). This was performed in order to investigate the activity of the lead compounds 1, 9, and 11 against the bacteriophage phiX174 by locating the ligand-target protein binding interaction active sites.

A new series of 8-methoxy-2-trimethoxyphenyl-3-substituted quinazoline-4(3)-one compounds were designed, synthesized, and screened for antitumor activity against three cell lines, namely, Hela, A549, and MDA compared to docetaxel as reference drug. The molecular docking was performed using Autodock Vina program and 20 ns molecular dynamics (MD) simulation was performed using GROMACS 2018.1 software. Compound 6 was the most potent antitumor of the new synthesized compounds and was evaluated as a VEGFR2 and EGFR inhibitor with (IC50, 98.1 and 106 nM respectively) compared to docetaxel (IC50, 89.3 and 56.1 nM respectively). Compounds 2, 6, 10, and 8 showed strong cytotoxic activities against the Hela cell line with IC50 of, 2.13, 2.8, 3.98, and 4.94 µM, respectively, relative to docetaxel (IC50, 9.65 µM). Compound 11 showed strong cytotoxic activity against A549 cell line (IC50, 4.03 µM) relative to docetaxel (IC50, 10.8 µM). Whereas compounds 6 and 9 showed strong cytotoxic activity against MDA cell line (IC50, 0.79, 3.42 µM, respectively) as compared to docetaxel (IC50, 3.98 µM).

The current work was conducted to synthesize several novel anti-inflammatory quinazolines having sulfamerazine moieties as new 3CLpro, cPLA2, and sPLA2 inhibitors. The thioureido derivative 3 was formed when compound 2 was treated with sulfamerazine. Also, compound 3 was reacted with NH2-NH2 in ethanol to produce the N-aminoquinazoline derivative. Additionally, derivative 4 was reacted with 4-hydroxy-3-methoxybenzaldehyde, ethyl chloroacetate, and/or diethyl oxalate to produce quinazoline derivatives 5, 6, and 12, respectively. The results of the pharmacological study indicated that the synthesized 4-6 and 12 derivatives showed good 3CLpro, cPLA2, and sPLA2 inhibitory activity. The IC50 values of the target compounds 4-6, and 12 against the SARS-CoV-2 main protease were 2.012, 3.68, 1.18, and 5.47 µM, respectively, whereas those of baicalein and ivermectin were 1.72 and 42.39 µM, respectively. The IC50 values of the target compounds 4-6, and 12 against sPLA2 were 2.84, 2.73, 1.016, and 4.45 µM, respectively, whereas those of baicalein and ivermectin were 0.89 and 109.6 µM, respectively. The IC50 values of the target compounds 4-6, and 12 against cPLA2 were 1.44, 2.08, 0.5, and 2.39 µM, respectively, whereas those of baicalein and ivermectin were 3.88 and 138.0 µM, respectively. Also, incubation of lung cells with LPS plus derivatives 4-6, and 12 caused a significant decrease in levels of sPLA2, cPLA2, IL-8, TNF-α, and NO. The inhibitory activity of the synthesized compounds was more pronounced compared to baicalein and ivermectin. In contrast to ivermectin and baicalein, bioinformatics investigations were carried out to establish the possible binding interactions between the newly synthesized compounds 2-6 and 12 and the active site of 3CLpro. Docking simulations were utilized to identify the binding affinity and binding mode of compounds 2-6 and 12 with the active sites of 3CLpro, sPLA2, and cPLA2 enzymes. Our findings demonstrated that all compounds had outstanding binding affinities, especially with the key amino acids of the target enzymes. These findings imply that compound 6 is a potential lead for the development of more effective SARS-CoV-2 Mpro inhibitors and anti-COVID-19 quinazoline derivative-based drugs. Compound 6 was shown to have more antiviral activity than baicalein and against 3CLpro. Furthermore, the IC50 value of ivermectin against the SARS-CoV-2 main protease was revealed to be 42.39 µM, indicating that it has low effectiveness.

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.

α-Glucosidase inhibition is an approved treatment for type 2 diabetes mellitus (T2DM). In an attempt to develop novel anti-α-glucosidase agents, two series of substituted imidazo[1,2-c]quinazolines, namely 6a-c and 11a-o, were synthesized using a simple, straightforward synthetic routes. These compounds were thoroughly characterized by IR, 1H and 13C NMR spectroscopy, as well as mass spectrometry and elemental analysis. Subsequently, the inhibitory activities of these compounds were evaluated against Saccharomyces cerevisiae α-glucosidase. In present study, acarbose was utilized as a positive control. These imidazoquinazolines exhibited excellent to great inhibitory potencies with IC50 values ranging from 12.44 ± 0.38 μM to 308.33 ± 0.06 μM, which were several times more potent than standard drug with IC50 value of 750.0 ± 1.5 μM. Representatively, compound 11j showed remarkable anti-α-glucosidase potency with IC50 = 12.44 ± 0.38 μM, which was 60.3 times more potent than positive control acarbose. To explore the potential inhibition mechanism, further evaluations including kinetic analysis, circular dichroism, fluorescence spectroscopy, and thermodynamic profile were carried out for the most potent compound 11j. Moreover, molecular docking studies and in silico ADME prediction for all imidazoquinazolines 6a-c and 11a-o were performed to reveal their important binding interactions, as well as their physicochemical and drug-likeness properties, respectively.

Many mitosis inhibitors are powerful anticancer drugs. Tremendous efforts have been made to identify new anti-mitosis compounds for developing more effective and less toxic anti-cancer drugs. We have identified LJK-11, a synthetic analog of 5, 8-disubstituted quinazolines, as a novel mitotic blocker. LJK-11 inhibited growth and induced apoptosis of many different types of tumor cells. It prevented mitotic spindle formation and arrested cells at early phase of mitosis. Detailed in vitro analysis demonstrated that LJK-11 inhibited microtubule polymerization. In addition, LJK-11 had synergistic effect with another microtubule inhibitor colchicine on blocking mitosis, but not with vinblastine or nocodazole. Therefore, LJK-11 represents a novel anti-microtubule structure. Understanding the function and mechanism of LJK-11 will help us to better understand the action of anti-microtubule agents and to design better anti-cancer drugs.

5H-benzo[h]thiazolo[2,3-b]quinazoline scaffold is known to have an antitumor effect on certain types of malignancies; however, its effect on hepatocellular carcinoma (HCC) remains unclear. Previously, we reported p-toluenesulfonic acid-promoted syntheses, molecular modeling and in vitro antitumor activity of 5H-benzo[h]thiazolo[2,3-b]quinazoline against human hepatoma (Hep-G2) cells where compounds 4A and 6A were found to be potent inhibitors among the series. In continuation to our previous effort to develop novel therapeutic strategies for HCC treatment, here we investigated the in vivo antitumor activity and the mechanism underlying the effects of 4A and 6A in N-nitrosodiethylamine (NDEA)-induced HCC using male Wistar rats. NDEA was administered weekly intraperitoneally at a dose of 100 mg/kg for 6 weeks. Various physiological and morphological changes, oxidative parameters, liver marker enzymes and cytokines were assessed to evaluate the antitumor effect of 4A and 6A. In addition, proton nuclear magnetic resonance-based serum metabolomics were performed to analyze the effects of 4A and 6A against HCC-induced metabolic alterations. Significant tumor incidences with an imbalance in carcinogen metabolizing enzymes and cellular redox status were observed in carcinogenic rats. Tumor inhibitory effects of 4A and 6A were noted by histopathology and biochemical profiles in NDEA-induced hepatic cancer. Compounds 4A and 6A had a potential role in normalizing the elevated levels of inflammatory mediators such as interleukin-1β (IL-1β), IL-2, IL-6 and IL-10. At molecular level, the real-time quantitative reverse-transcribed polymerase chain reaction analysis revealed that 4A and 6A attenuated the IL-6 gene overexpression in hepatic cancer. Further, orthogonal partial least squares discriminant analysis scores plot demonstrated a significant separation of 4A and 6A-treated groups from carcinogen control group. Both the compounds have potential to restore the imbalanced metabolites due to HCC, signifying promising hepatoprotective activities. All these findings suggested that 4A and 6A could be potential drug candidates to treat HCC.

Some novel fluorinated quinazolines (5a-j) were designed and synthesized to be evaluated for their anticonvulsant activity and their neurotoxicity. Structures of all newly synthesized compounds were confirmed by their infrared (IR), mass spectrometry (MS) spectra, ¹H nuclear magnetic resonance (NMR), 13C-NMR, and elemental analysis (CHN). The anticonvulsant activity was evaluated by a subcutaneous pentylenetetrazole (scPTZ) test and maximal electroshock (MES)-induced seizure test, while neurotoxicity was evaluated by a rotorod test. The molecular docking was performed for all newly-synthesized compounds to assess their binding affinities to the GABA-A receptor in order to rationalize their anticonvulsant activities in a qualitative way. The data obtained from the molecular modeling was correlated with that obtained from the biological screening. These data showed considerable anticonvulsant activity for all newly-synthesized compounds. Compounds 5b, 5c, and 5d showed the highest binding affinities toward the GABA-A receptor, along with the highest anticonvulsant activities in experimental mice. These compounds also showed low neurotoxicity and low toxicity in the median lethal dose test compared to the reference drugs. A GABA enzymatic assay was performed for these highly active compounds to confirm the obtained results and explain the possible mechanism for anticonvulsant action. The most active compounds might be used as leads for future modification and optimization.