Recent advances in the pharmacological diversification of quinazoline/quinazolinone hybrids

Alternative and efficient one-pot three-component synthesis of substituted 2-aryl-4-styrylquinazolines/4-styrylquinazolines from synthetically available 1-(2-aminophenyl)-3-arylprop-2-en-1-ones: characterization and evaluation of their antiproliferative activities

In this study, an alternative and efficient one-pot three-component synthesis approach to develop a new series of (E)-2-aryl-4-styrylquinazolines and (E)-4-styrylquinazolines is described. According to this approach, the target compounds were synthesized straightforward in high yields and in short reaction times from substituted 1-(2-aminophenyl)-3-arylprop-2-en-1-ones via its well-Cu(OAc)2-mediated cyclocondensation reactions with aromatic aldehydes or its well-catalyst-free cyclocondensation reactions with trimethoxy methane (trimethyl orthoformate), and ammonium acetate under aerobic conditions. This is an operationally simple, valuable, and direct method to synthesize 2-aryl- and non-C2-substituted quinazolines containing a styryl framework at C4 position from cheap and synthetically available starting materials. All the synthesized compounds were submitted to the US National Cancer Institute for in vitro screening. The bromo- and chloro-substituted quinazolines 5c and 5d displayed a potent antitumor activity against all the tested subpanel tumor cell lines with IC50 (MG-MID) values of 5.25 and 5.50 μM, and a low cytotoxic effect with LC50 (MG-MID) values of 91.20 and 84.67 μM, respectively, indicating a low toxicity of these compounds to normal human cell lines, as required for potential antitumor agents.

Green light-mediated dual eosin Y/PdII-catalyzed C(sp2)-H arylation of N-H unprotected 2-arylquinazolinones

We report herein an eosin Y/Pd(II) dual catalytic approach for regio- and chemoselective C(sp2)-H monoarylation of N-H unprotected 2-phenyl quinazolinone derivatives under green light irradiation with no necessity for any base/additive/external oxidant. The free N-H moiety was post-modified for quinazolinone scaffold diversification and C-H annulation.

New quinazolin-2,4-dione derivatives incorporating acylthiourea, pyrazole and/or oxazole moieties as antibacterial agents via DNA gyrase inhibition

This article contributes to the search for new therapeutic agents for treatment of diseases caused by bacterial pathogens. In this study, a new series of compounds incorporating numerous bioactive moieties such as quinazolin-2,4-dione, acylthiourea linkage, and/or five membered nitrogen heterocycles (pyrazole and oxazole) 2-5a-c was described to identify new antibacterial drug candidates via inhibition of DNA gyrase enzyme. The precursor N-[N'-(2-cyano-acetyl)-hydrazinocarbothioyl]-4-(2,4-dioxo-1,4-dihydro-2H-quinazolin-3-yl)-benzamide 2 was prepared by treatment of compound 1 with ammonium thiocyanate and cyanoacetic acid hydrazide through multicomponent reaction (MCR). In addition, compounds 3a-d and 4a-b were synthesized by treatment of 2 with aromatic aldehydes and/or ketones through Knoevenagel reaction, affording high purity products in satisfactory yields. Moreover, new heterocyclic moieties such as pyrazole and/or oxazole attached to quinazolin-2,4-dione core 5a-c were synthesized by treatment of 3c with different nucleophilic reagents like hydrazine, phenyl hydrazine and hydroxyl amine, respectively. Subsequently, the obtained products were structurally characterized by IR, 1H-, 13C-NMR, and MS analyses. The minimum inhibitory concentration (MIC) and antibacterial potency of all compounds were estimated against two G-ve (E. coli and P. aeruginosa), and two G+ve bacteria (B. subtilis and S. aureus). Encouragingly, compound 3c demonstrated the best antibacterial activity against all the strains of the tested pathogenic bacteria at low concentrations compared with the standard drug, Ciprofloxacin. Electron withdrawing groups such as -NO2 and -Cl enhance the antibacterial activity. Next, a molecular docking study between the synthesized derivatives and the target enzyme, DNA gyrase enzyme (PDB: 2xct) was undertaken to investigate intermolecular interactions between the compounds and target enzyme.

Copper-Catalyzed Decarboxylation Cross-Coupling Cascade Reaction for Synthesis of Fused Dihydro-benzoxazinones

A protocol for a tandem copper-catalyzed intermolecular decarboxylation cross-coupling cascade between o-bromobenzoic acids and proline or piperic acid has been disclosed. The developed protocol allows access to a variety of synthetically useful fused benzoxazinones scaffolds with high efficiency and good functional group compatibility. A mechanistically sequential approach for the decarboxylation and dehydration coupling process was presented.

One-pot synthesis of quinazolinone heterocyclic compounds using functionalized SBA-15 with natural material ellagic acid as a novel nanocatalyst

The nanoporous compound SBA-15 was functionalized using (3-aminopropyl)trimethoxysilane (APTES). Then the obtained product was modified with ellagic acid (ELA), a bioactive polyphenolic compound. The structure of the prepared nanoporous composition SBA-15@ELA was extensively characterized and confirmed by various techniques, such as Fourier-transform infrared (FT-IR) spectroscopy, Energy dispersive X-ray (EDX) elemental analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption-desorption isotherms (BET). The novel, recoverable, heterogenous SBA-15@ELA nanoporous compound was used to investigate its catalytic effect in the synthesis of 4-oxo-quinazoline derivatives (19 examples) with high yields (78-96%), as an important class of nitrogen-containing heterocyclic compounds. The use of an inexpensive mesoporous catalyst with a high surface area, along with easy recovery by simple filtration are among the advantages of this catalysis research work. The catalyst has been used in at least 6 consecutive runs without a significant loss of its activity.

Design and synthesis of N-aryl-2-trifluoromethyl-quinazoline-4-amine derivatives as potential Werner-dependent antiproliferative agents

To discover new Werner (WRN) helicase inhibitors, a series of N-aryl-2-trifluoromethyl-quinazoline-4-amine derivatives were designed and synthesized through a structural optimization strategy, and the anticancer activities of 25 new target compounds against PC3, K562, and HeLa cell lines were evaluated by the MTT assay. Some of these compounds exhibited excellent inhibitory activity against three different cancer cell lines. Compounds 6a, 8i, and 13a showed better antiproliferative activity against K562 cells, with IC50 values of 3871.5, 613.6 and 134.7 nM, respectively, than did paclitaxel (35.6 nM), doxorubicin (2689.0 nM), and NSC 617145 (20.3 nM). To further verify whether the antiproliferative activity of these compounds is dependent on WRN, PC3 cells overexpressing WRN (PC3-WRN) were constructed to further study their antiproliferative potency in vitro, and the inhibition ratio and IC20 values showed that compounds 6a, 8i, and 13a were more sensitive to PC3-WRN than were the control group cells (PC3-NC). The IC20 ratios of compounds 6a, 8i, and 13a to PC3-NC and PC3-WRN were 94.3, 153.4 and 505.5, respectively. According to the docking results, the compounds 6a, 8i, and 13a overlapped well with the binding pocket of 6YHR. Further study demonstrated that among the tested compounds, 13a was the most sensitive to PC3-WRN. In summary, our research identified a series of N-aryl-2-trifluoromethyl-quinazoline-4-amine derivatives as potential WRN-dependent anticancer agents.

Synthesis, In Vivo Anticonvulsant Activity Evaluation and In Silico Studies of Some Quinazolin-4(3H)-One Derivatives

Two series, "a" and "b", each consisting of nine chemical compounds, with 2,3-disubstituted quinazolin-4(3H)-one scaffold, were synthesized and evaluated for their anticonvulsant activity. They were investigated as dual potential positive allosteric modulators of the GABAA receptor at the benzodiazepine binding site and inhibitors of carbonic anhydrase II. Quinazolin-4(3H)-one derivatives were evaluated in vivo (D1-3 = 50, 100, 150 mg/kg, administered intraperitoneally) using the pentylenetetrazole (PTZ)-induced seizure model in mice, with phenobarbital and diazepam, as reference anticonvulsant agents. The in silico studies suggested the compounds act as anticonvulsants by binding on the allosteric site of GABAA receptor and not by inhibiting the carbonic anhydrase II, because the ligands-carbonic anhydrase II predicted complexes were unstable in the molecular dynamics simulations. The mechanism targeting GABAA receptor was confirmed through the in vivo flumazenil antagonism assay. The pentylenetetrazole experimental anticonvulsant model indicated that the tested compounds, 1a-9a and 1b-9b, present a potential anticonvulsant activity. The evaluation, considering the percentage of protection against PTZ, latency until the onset of the first seizure, and reduction in the number of seizures, revealed more favorable results for the "b" series, particularly for compound 8b.

Photogenerated chlorine radicals activate C(sp3)-H bonds of alkylbenzenes to access quinazolinones

An Fe-catalyzed visible-light induced condensation of alkylbenzenes with anthranilamides has been developed. Upon irradiation, the trivalent iron complex could generate chlorine radicals, which successfully abstracted the hydrogen of benzylic C-H bonds to form benzyl radicals. And these benzyl radicals were converted into oxygenated products under air conditions, which subsequently reacted with anthranilamides for the synthesis of quinazolinones.

Synthesis of tetrahydroquinazolines from 2-aminobenzonitriles and alkylidene malonates via 1,4-conjugate addition and an unprecedented rearrangement reaction

An efficient methodology for the synthesis of highly diverse tetrahydroquinazoline scaffolds from 2-aminobenzonitriles and alkylidene malonates via 1,4-conjugate addition followed by an unprecedented rearrangement has been demonstrated. The methodology is further applicable for the synthesis of quinazolines and tetracyclic compounds. Some of the synthesized compounds exhibit photophysical properties.

Activity against Mycobacterium tuberculosis of a new class of spirooxindolopyrrolidine embedded chromanone hybrid heterocycles

A new class of structurally intriguing heterocycles embedded with spiropyrrolidine, oxindole and chromanones was prepared by regio- and stereoselectively in quantitative yields using an intermolecular tandem cycloaddition protocol. The compounds synthesized were assayed for their anti-mycobacterial activity against Mycobacterium tuberculosis (Mtb) H37Rv and isoniazid-resistant (katG and inhA promoter mutations) clinical Mtb isolates. Four compounds exhibited significant antimycobacterial activity against Mtb strains tested. In particular, a compound possessing a fluorine substituted derivative displayed potent activity at 0.39 μg mL-1 against H37Rv, while it showed 0.09 μg mL-1 and 0.19 μg mL-1 activity against inhA promoter and katG mutation isolates, respectively. A molecular docking study was conducted with the potent compound, which showed results that were consistent with the in vitro experiments.

Ultra-high-performance liquid chromatography-quadrupole time of flight tandem mass spectrometry based in vitro metabolite profiling of DK-GV-04P, a novel anticancer molecule under drug discovery

DK-GV-04P, chemically identified as 3-cinnamyl-2-(4-methoxyphenyl) quinazolin-4(3H)-one, is an investigational molecule synthesized at the Chemical Biology Laboratory of the National Institute of Pharmaceutical Education and Research-Ahmedabad. The compound has shown potential anticancer activity against squamous CAL27 cell lines. Metabolite identification and characterization are critical in drug discovery, providing key insights into a compound's pharmacokinetics, pharmacodynamics safety, and metabolic fate. The primary aim of the study was to identify and characterize the in vitro metabolites of DK-GV-04P. In silico identification of the site of metabolism was also carried out using xenosite online software. The molecule was incubated with human liver microsomes and human S9 liver fraction to generate in vitro metabolites, which were further identified and characterized using ultra-high-performance liquid chromatography-quadrupole time of flight tandem mass spectrometry. A total of nine metabolites (four phase I and five phase II) were identified and characterized through tandem mass spectrometry. The major biotransformation pathways involved in metabolism of DK-GV-04P were hydroxylation, O-demethylation and glucuronidation. In addition to this, a detailed biotransformation pathway of DK-GV-04P has been established in this study.

Synthesis and molecular docking simulations of novel azepines based on quinazolinone moiety as prospective antimicrobial and antitumor hedgehog signaling inhibitors

A series of novel azepine derivatives based on quinazolinone moiety was synthesized through the reaction of quinazolinone chalcones (2a-d) either with 2-amino aniline in acidic medium to give diazepines (3a-d) or with 2-aminophenol to offer oxazepine (4a-d). The structure of the synthesized compounds was confirmed via melting points, elemental analyses, and different spectroscopic techniques. Moreover, these newly compounds mode of action was investigated in-silico using molecular docking against the outer membrane protein A (OMPA), exo-1,3-beta-glucanase for their antimicrobial activity, and against Smoothened (SMO), transcription factor glioma-associated homology (SUFU/GLI-1), the main proteins of Hedgehog signaling pathway to inspect their anticancer potential. Our results showed that, diazepine (3a) and oxazepine (4a) offered the highest binding energy against the target OMPA/ exo-1,3-beta-glucanase proteins and exhibited the potent antimicrobial activities against E. coli, P. aeruginosa, S. aureus, B. subtilis, C. Albicans and A. flavus. As well, diazepine (3a) and oxazepine (4a) achieved the best results among the other compounds, in their binding energy against the target SMO, SUFU/GLI-1 proteins. The in-vitro cytotoxic study was done for them on panel of cancer cell lines HCT-116, HepG2, and MCF-7 and normal cell line WI-38. Conclusively, it was revealed that molecular docking in-silico simulations and the in-vitro experiments were agreed. As a result, our findings elucidated that diazepine (3a) and oxazepine (4a), have the potential to be used as antimicrobial agents and as possible cancer treatment medications.

Visible-light photocatalyzed C-N bond activation of tertiary amines: a three-component approach to synthesize quinazolines

A metal-free three-component approach has been developed to prepare 2,4-disubstituted quinazolines from o-acylanilines, trialkylamines and ammonium chloride under visible-light using eosin Y as the photocatalyst. The notable features of this work include (i) the use of tertiary amines as an alkyl synthon and triethanolamine as a C2-OH synthon; (ii) good functional group tolerance with 52%-98% yields; (iii) proof of concept with o-amino benzaldehyde as a substrate to deliver 2-methyl quinazoline 3pa; and (iv) gram-scale synthesis of compounds 3ga, 3ja and 3ma. A reductive quenching mechanism was proposed based on the control studies and redox potential values.

Cyclizations of Alkenyl(Alkynyl)-Functionalized Quinazolinones and their Heteroanalogues: A Powerful Strategy for the Construction of Polyheterocyclic Structures

Quinazolin-4-one, its heteroanalogues, and derivatives represent an outstandingly important class of compounds in modern organic, medicinal, and pharmaceutical chemistry, as these molecular structures are noted for their wide synthetic and pharmacological potential. In the last years, ever-increasing research attention has been paid to quinazolinone derivatives bearing alkenyl and alkynyl substituents on the pyrimidinone nucleus. The original structural combination of synthetically powerful endocyclic amidine (or amidine-related) and exocyclic unsaturated moieties provides a driving force for cyclizations, which offer an efficient toolkit to construct a variety of fused pyrimidine systems with saturated N- and N,S-heterocycles. In this connection, the present review article is mainly aimed at systematic coverage of the progress in using alkenyl(alkynyl)quinazolinones and their heteroanalogues as convenient bifunctional substrates for regioselective annulation of small- and medium-sized heterocyclic nuclei. Much attention is paid to elucidating the structural and electronic effects of reagents on the regio- and stereoselectivity of the cyclizations as well as to clarifying the relevant reaction mechanisms.

Synthesis of Selenium-Containing N-Quinazolinyl Acroleins via a 3,3-Radical Rearrangement Cascade Reaction

An effective approach for the construction of 2-aryl-3-(3-oxo-1-aryl-2-(organoselanyl)prop-1-en-1-yl)quinazolin-4(3H)-ones was developed. Excellent to almost quantitative yields were obtained by the cascade reaction of propargyl quinazoline-4-yl ethers, diselenides, and 70% tert-butyl hydrogen peroxide aqueous solution under metal-free and mild conditions. The synthesized hybrids, with conglomeration of quinazolinone, organoselenium, aldehyde, and fully substituted alkene moieties in one molecule, will have the potential for applications in development of new drugs or drug candidates.

Novel N-(3-ethynyl Phenyl)-6,7-bis(2-methoxyethoxy)Quinazoline-4-amine Derivatives: Synthesis, Characterization, Anti-cancer Activity, In-silico and DFT Studies

BACKGROUND

Cancer is one of the most common reasons for mortality in the world. A continuous effort to develop effective anti-cancer drugs with minimum side effects has become necessary. The use of small-molecule drugs has revolutionized cancer research by inhibiting cancer cell survival and proliferation. Quinazolines are a class of bioactive heterocyclic compounds with active pharmacophores in several anti-cancer drugs. Such small molecule inhibitors obstruct the significant signals responsible for cancer cell development, thus blocking these cell signals to prevent cancer development and spread.

OBJECTIVE

In the current study, novel quinazoline derivatives structurally similar to erlotinib were synthesized and explored as novel anti-cancer agents.

METHODS

All the synthesized molecules were confirmed by spectroscopic techniques like 1H NMR, 13C NMR, and ESI-MS. Various techniques were applied to study the protein-drug interaction, DFT analysis, Hirshfeld surface, and target prediction. The molecules were screened in vitro for their anti-cancer properties against 60 human tumor cell lines. The growth inhibitory properties of a few compounds were studied against the MCF7 breast cancer cell line.

RESULTS

The activity of compounds 9f, 9o, and 9s were found to be active. However, compound 9f is more active when compared with other compounds.

CONCLUSION

Some synthesized compounds were active against different cancer cell lines. The in-vitro study results were found to be in agreement with the predictions from in-silico data. The selected molecules were further subjected to get the possible mechanism of action against different cancer cells.

A chloride-responsive molecular switch: driving ion transport and empowering antibacterial properties

A molecular switch was developed to recognize and transport Cl- across lipid bilayers. The XRD-crystal structure and NOESY NMR spectra of a potent 4-aminoquinazoline analogue confirmed Cl--induced conformation changes. Systematic biophysical studies revealed that the quinazoline moiety forms cooperative interactions of H+ and Cl- ions with the thiourea moiety, resulting in the transport of H+/Cl- across the membranes. A pH-dependent analysis revealed that the transport of Cl- by the potent compound increased in an acidic environment. The potent compound could also transport H+/Cl- across Gram-positive bacteria, leading to antibacterial activities.

Synthesis and Biological Evaluation of 2-Substituted Quinazolin-4(3H)-Ones with Antiproliferative Activities

Sixteen new 2-substituted quinazolines were synthesized using a straightforward methodology starting from 2-methoxybezoic acid or 3-methoxy-2-naphthoic acid. The anti-proliferative activity of the target compounds was evaluated against nine cancer cell lines. Additionally, all the compounds were screened for their potency and selectivity against a panel of 109 kinases and four bromodomains, using Differential Scanning Fluorimetry (DSF). Compound 17 bearing a 2-methoxyphenyl substitution along with a basic side chain displayed a remarkable profile against the majority of the tested cell lines.

Design, Synthesis of Novel 1,2,3-Triazole Pendent Quinazolinones and Their Cytotoxicity against MCF-7 Cell Line

A library of 6-(((1-(substitutedphenyl)-1H-1,2,3-triazol-4-yl)methyl) amino)-3-methylquinazolin-4(3H)-one analogues synthesized from Isatin precursor through a series of nitration, reduction, hydrolysis, cyclization and click reaction. The structures of compounds were characterized by spectral data including IR, 1 H-NMR, 13 C NMR and Mass. The novel quinazolinone - 1,2,3-triazoles were screened for their cytotoxicity against the human breast adenocarcinoma cell lines MCF-7 by MTT assay. 4-Isopropyl and 2-bromo substituted analogues executed high activity against MCF-7 cell line with IC50 value of 10.16±0.07 μM and 11.23±0.20 μM compared to the Doxorubicin whose IC50 value is 10.81±0.03 μM. The activity of remaining compounds is good to moderate. Further, the molecular docking studies against the crystal structure of Epidermal Growth Factor Receptor delivered the best binding energies and the interactions such as H-bond and hydrophobic are inevitable. The predicted pharmacokinetic properties results showed that these compounds have more drug likeness properties.

Arylidene and amino spacer-linked rhodanine-quinoline hybrids as upgraded antimicrobial agents

Antibiotic resistance associated with various microorganisms such as Gram-positive, Gram-negative, fungal strains, and multidrug-resistant tuberculosis increases the risk of healthcare survival. Preliminary therapeutics becoming ineffective that might lead to noteworthy mortality presents a crucial challenge for the scientific community. Hence, there is an urgent need to develop hybrid compounds as antimicrobial agents by combining two or more bioactive heterocyclic moieties into a single molecular framework with fewer side effects and a unique mode of action. This review highlights the recent advances (2013-2023) in the pharmacology of rhodanine-linked quinoline hybrids as more effective antimicrobial agents. In the drug development process, linker hybrids acquire the top position due to their excellent π-stacking and Van der Waals interaction with the DNA active sites of pathogens. A molecular hybridization strategy has been optimized, indicating that combining these two bioactive moieties with an arylidene and an amino spacer linker increases the antimicrobial potential and reduces drug resistance. Moreover, the structure-activity relationship study is discussed to express the role of various functional groups in improving and decrementing antimicrobial activities for rational drug design. Also, a linker approach may accelerate the development of dynamic antimicrobial agents through molecular hybridization.

Arene Ruthenium(II)-Catalyzed Sustainable Synthesis of 2,4-Disubstituted Quinazolines via Acceptorless Dual Dehydrogenative Coupling of Alcohols

We demonstrate an efficient and sustainable strategy for the direct synthesis of 2,4-disubstituted quinazolines by arene Ru(II)benzhydrazone complex via the eco-friendly sequential acceptorless dehydrogenative coupling of 2-aminobenzhydrol derivatives and benzyl alcohols for the first time. The new ruthenium(II) complex of the general formula [(η6-p-cymene)Ru(L1)Cl] (L1-acenaphthenequinone hydrazone) has been synthesized and characterized by analytical, spectroscopic, and single-crystal X-ray diffraction techniques. A broad spectrum of 2,4-disubstituted quinazolines have been successfully derived (25 examples) from 2-aminobenzhydrol derivatives with various benzyl alcohols using 1 mol % of catalyst loading in the presence of NH4OAc. The present protocol is highly selective and produces a maximum yield of 95% under mild reaction conditions. The different reaction intermediates detected through control experiments such as aldehyde, 2-aminobenzophenone, benzylidene(amino)phenylmethanone, and 1,2-dihydroquinazoline are isolated and authenticated by the NMR study. Gratifyingly, the coupling reaction is a simple and atom economic with the release of water and hydrogen gas as the only byproducts. A gram-scale synthesis of 2-(4-methoxyphenyl)-4-phenylquinazoline illustrates the synthetic utility of the present protocol.

Deep Eutectic Solvents: An Eco-friendly Design for Drug Engineering

In the spirit of circular economy and sustainable chemistry, the use of environmentally friendly chemical products in pharmacy has become a hot topic. In recent years, organic solvents have been the subject of a great range of restriction policies due to their harmful effects on the environment and toxicity to human health. In parallel, deep eutectic solvents (DESs) have emerged as suitable greener solvents with beneficial environmental impacts and a rich palette of physicochemical advantages related to their low cost and biocompatibility. Additionally, DESs can enable remarkable solubilizing effect for several active pharmaceutical ingredients (APIs), thus forming therapeutic DESs (TheDESs). In this work, special attention is paid to DESs, presenting a precise definition, classification, methods of preparation, and characterization. A description of natural DESs (NaDESs), i. e., eutectic solvents present in natural sources, is also reported. Moreover, the present review article is the first one to detail the different approaches for judiciously selecting the constituents of DESs in order to minimize the number of experiments. The role of DESs in the biomedical and pharmaceutical sectors and their impact on the development of successful therapies are also discussed.

Synthesis, in silico and in vitro antimicrobial efficacy of substituted arylidene-based quinazolin-4(3H)-one motifs

Introduction: Quinazolin-4(3H)-one derivatives have attracted considerable attention in the pharmacological profiling of therapeutic drug targets. The present article reveals the development of arylidene-based quinazolin-4(3H)-one motifs as potential antimicrobial drug candidates. Methods: The synthetic pathway was initiated through thermal cyclization of acetic anhydride on anthranilic acid to produce 2-methyl-4H-3,1-benzoxazan-4-one 1, which (upon condensation with hydrazine hydrate) gave 3-amino-2-methylquinazolin-4(3H)-one 2. The reaction of intermediate 2 at its amino side arm with various benzaldehyde derivatives furnished the final products, in the form of substituted benzylidene-based quinazolin-4(3H)-one motifs 3a-l, and with thiophene-2-carbaldehyde to afford 3 m. The purified targeted products 3a-m were effectively characterized for structural authentication using physicochemical parameters, microanalytical data, and spectroscopic methods, including IR, UV, and 1H- and 13C-NMR, as well as mass spectral data. The substituted arylidene-based quinazolin-4(3H)-one motifs 3a-m were screened for both in silico and in vitro antimicrobial properties against selected bacteria and fungi. The in silico studies carried out consisted of predicted ADMET screening, molecular docking, and molecular dynamics (MD) simulation studies. Furthermore, in vitro experimental validation was performed using the agar diffusion method, and the standard antibacterial and antifungal drugs used were gentamicin and ketoconazole, respectively. Results and discussion: Most of the compounds possessed good binding affinities according to the molecular docking studies, while MD simulation revealed their levels of structural stability in the protein-ligand complexes. 2-methyl-3-((thiophen-2-ylmethylene)amino) quinazolin-4(3H)-one 3 m emerged as both the most active antibacterial agent (with an minimum inhibitory concentration (MIC) value of 1.95 μg/mL) against Staphylococcus aureus and the most active antifungal agent (with an MIC value of 3.90 μg/mL) against Candida albicans, Aspergillus niger, and Rhizopus nigricans.

Novel iodoquinazolinones bearing sulfonamide moiety as potential antioxidants and neuroprotectors

In a search for new antioxidants, a set of new iodoquinazolinone derivatives bearing benzenesulfonamide moiety and variable acetamide pharmacophores 5-17 were designed and synthesized. The structures of the synthesized compounds were confirmed based on spectral data. Compounds 5-17 were screened using in vitro assay for their antioxidant potential and acetylcholinesterase (AChE) inhibitory activity. The 2-(6-iodo-4-oxo-3-(4-sulfamoylphenyl)-3,4-dihydroquinazolin-2-ylthio)-N-(pyrazin-2-yl) acetamide 14 was the most active scaffold with potent AChE inhibitory activity. Compound 14 showed relative safety with a median lethal dose of 300 mg/kg (LD50 = 300 mg/kg), in an acute toxicity study. The possible antioxidant and neuroprotective activities of 14 were evaluated in irradiated mice. Compound 14 possessed in vivo AChE inhibitory activity and was able to modify the brain neurotransmitters. It was able to cause mitigation of gamma radiation-induced oxidative stress verified by the decline in Myeloperoxidase (MPO) and increase of glutathione (GSH) levels. Also, 14 restored the alterations in behavioral tests. Molecular docking of 14 was performed inside MPO and AChE active sites and showed the same binding interactions as that of the co-crystallized ligands considering the binding possibilities and energy scores. These findings would support that 14 could be considered a promising antioxidant with a neuromodulatory effect.

Diversity-oriented synthesis of 1H-1,2,3-triazole tethered pyrazolo[5,1-b]quinazoline hybrids as antimicrobial agents

A straightforward and high yielding synthetic approach is employed to synthesize the novel 1H-1,2,3-triazole tethered pyrazolo[5,1-b]quinazoline hybrids 7(a-t) as new antimicrobial agents with two pharmacophore in the effective two step synthesis. The first step is the four component one-pot synthesis of highly functionalized pyrazolo[5,1-b]quinazolines 5(a-j) catalysed by TBAB, with the advantages of an environmentally benign reaction, high yielding, quick reaction time, and operational simplicity. In the subsequent stage, CuSO4/NaAsc system was employed to synthesize the 1H-1,2,3-triazole tethered pyrazolo[1,5-b]quinazoline hybrids as 1H-1,2,3-triazoles are the structures of great diversity and importance in diverse therapeutics containing numerous biological activities. The antimicrobial activity of all the synthesized hybrid compounds have been preliminary tested using the broth dilution technique against two gram-positive and two gram-negative bacterial strains as well as two fungal strains. In comparison to standard drugs, the majority of compounds exhibited good to moderate activity. Among the all the compounds, 7a (MIC 18.54 μM) against Pseudomonas aeruginosa, 7j (MIC 89.76 μM) against Bacillus subtilis as well as Rhizopus oryzae and 7t (MIC 84.88 μM) against Aspergillus parasiticus have remarkable antimicrobial potency as compared to standard drug.

Design, synthesis, computational study and cytotoxic evaluation of some new quinazoline derivatives containing pyrimidine moiety

Quinazoline derivatives, as an important category of heterocyclic compounds, have received much attention for the design and development of new drugs due to their various pharmacological properties. Besides, there is a great deal of evidence showing pyrimidine analogs as anticancer agents. Thus, in the present study, for the design of new target compounds with cytotoxic activity, we focused on various quinazolinone and pyrimidine hybrids. A new series of quinazoline-pyrimidine hybrid derivatives (6a-6n) have been designed and synthesized as novel antiproliferative agents. All the synthesized compounds characterized based on their IR, NMR and Mass spectroscopic data. Antiproliferative activities of the new compounds were evaluated against three human cancer cell lines (MCF-7, A549, SW-480). The compounds were found to have appropriate potential with IC50 values ranging from 2.3 ± 5.91 to 176.5 ± 0.7 μM against the tested cell lines. Compound 6n exerted the highest antiproliferative activity with IC50 values of 5.9 ± 1.69 μM, 2.3 ± 5.91 μM and 5.65 ± 2.33 μM against A549, SW-480 and MCF-7 respectively. The results indicated that 6n could induce apoptosis in A549 cell line in a dose dependent manner and arrest in the S phase of cell cycle. Docking studies were also done to investigate the detailed binding pattern of the synthesized compounds against EGFR. Furthermore, molecular dynamic simulation and binding free energy calculation have been done to rescore initial docking pose of the synthesized compounds using ensemble-based MMGB/PBSA free energy method. According to the results, free energy calculation confirmed biological activity of compounds and also, Arg 817 and Lys 721 residues had the pivotal role in the high potency of 6n. Finally, the drug likeness and in silico ADME study were also predicted.

Design, synthesis, anticancer activity and docking studies of novel quinazoline-based thiazole derivatives as EGFR kinase inhibitors

The in vitro anticancer efficacy of a new series of quinazoline-based thiazole derivatives was explored. Three cancer cell lines, MCF-7, HepG2, and A548, as well as the normal Vero cell lines, were tested employing the synthesized quinazoline-based thiazole compounds (4a-j). All of these compounds showed a moderate to significant cytotoxic impact that would have been noticeable and, in some cases, much more pronounced than the widely used drug erlotinib. For the MCF-7, HepG2, and A549 cell lines, respectively, the IC50 values of compound 4i were 2.86, 5.91, and 14.79 μM while those of compound 4j were 3.09, 6.87, and 17.92 μM. For their in vitro inhibitory effects against different EGFR kinases, such as the wild-type, L858R/T790 M, and L858R/T790 M/C797S, all the synthesized compounds were tested. The IC50 values for compound 4f against the wild-type, L858R/T790 M, and L858R/T790 M/C797S mutant EGFR kinases were 2.17, 2.81, and 3.62 nM, respectively. Investigations on the molecular docking of significant molecules indicated potential mechanisms of binding into the EGFR kinase active sites. By using in-silico simulations, compounds' putative drug-like qualities were verified. Finally, it has been shown that the newly synthesized compounds 4i and 4j are good candidates and beneficial for future design, optimization, and research to build more potent and selective EGFR kinase inhibitors with higher anticancer activity.

Environmentally Friendly Approach to the Synthesis of 3-[Benzylideneamino]-2-methylquinazolin-4(3H)-one Derivatives and Calculation of Their Toxicity

Application of deep eutectic solvents in synthesis of different heterocyclic compounds was proven very efficient. These solvents are a new generation of green solvents showing excellent potential for different purposes, where they are used as environmentally acceptable substitute for toxic and volatile organic solvents. This research describes their application in the synthesis of series of quinazolinone Schiff bases in combination with microwave, ultrasound-assisted and mechanochemical methods. First, a model reaction was performed in 20 different deep eutectic solvents to find the best solvent and then reaction conditions (solvent, temperature and reaction time) were optimized for each method. Afterwards, 40 different quinazolinone derivatives were synthesized in choline chloride/malonic acid (1 : 1) DES by each method and compared by their yields. Here we show that deep eutectic solvents can be very efficient in the synthesis of quinazolinone derivatives as an excellent substitution for volatile organic solvents. With green chemistry approach in mind, we have also performed a calculation on compounds' toxicity and solubility, showing that most of them possess toxic and mutagenic properties with low water solubility.

An Oxidant-Free and Mild Strategy for Quinazolin-4(3H)-One Synthesis via CuAAC/Ring Cleavage Reaction

An oxidant-free and highly efficient synthesis of phenolic quinazolin-4(3H)-ones was achieved by simply stirring a mixture of 2-aminobenzamides, sulfonyl azides, and terminal alkynes. The intermediate N-sulfonylketenimine underwent two nucleophilic additions and the sulfonyl group eliminated through the power of aromatization. The natural product 2-(4-hydroxybenzyl)quinazolin-4(3H)-one can be synthesized on a large scale under mild conditions with this method.

New Hybrid Tetrahydropyrrolo[3,2,1-ij]quinolin-1-ylidene-2-thioxothiazolidin-4-ones as New Inhibitors of Factor Xa and Factor XIa: Design, Synthesis, and In Silico and Experimental Evaluation

Despite extensive research in the field of thrombotic diseases, the prevention of blood clots remains an important area of study. Therefore, the development of new anticoagulant drugs with better therapeutic profiles and fewer side effects to combat thrombus formation is still needed. Herein, we report the synthesis and evaluation of novel pyrroloquinolinedione-based rhodanine derivatives, which were chosen from 24 developed derivatives by docking as potential molecules to inhibit the clotting factors Xa and XIa. For the synthesis of new hybrid derivatives of pyrrolo[3,2,1-ij]quinoline-2-one, we used a convenient structural modification of the tetrahydroquinoline fragment by varying the substituents in positions 2, 4, and 6. In addition, the design of target molecules was achieved by alkylating the amino group of the rhodanine fragment with propargyl bromide or by replacing the rhodanine fragment with 2-thioxoimidazolidin-4-one. The in vitro testing showed that eight derivatives are capable of inhibiting both coagulation factors, two compounds are selective inhibitors of factor Xa, and two compounds are selective inhibitors of factor XIa. Overall, these data indicate the potential anticoagulant activity of these molecules through the inhibition of the coagulation factors Xa and XIa.

Diversity oriented synthesis and SAR studies of new quinazolinones and related compounds as insecticidal agents against Culex pipiens L. Larvae and associated predator

The ongoing study reports the synthesis, spectroscopic analyses and larvicidal efficacy of novel series of quinazolinone derivatives and related compounds. The structures of the products were confirmed relied on their analytical and spectral data (IR, ¹H NMR, and ¹³C NMR). The spectral documentation promoted the successful isolation of the desirable compounds. The insecticidal activities of the synthesized compounds were assessed against laboratory and field strains of Culex pipiens larvae and a predator from the same ecological niche, Cybister tripunctatus. The results revealed that most of the tested compounds showed high potencies against lab strain of C. pipiens larvae with low resistance ratios in filed strain. In particular, compounds 15, 6 and 16 showed low LC₅₀ values, 0.094, 0.106, 0.129 (µg/mL), respectively against lab strain of C. pipiens larvae. The present study also explored the toxicity of tested compounds against field strain of non-target C. tripunctatus. Most of tested compounds were safer than temephos, especially 15 and 6 with SI/PSF values 96.746 and 83.167, respectively. Structure-activity relationship (SAR) was discussed the effect of substituents insertion on the derivatives activities. Quinazolinone derivatives and related compounds are promising compounds in the mosquito control programs and further studies are recommended to develop more effective derivatives and reveal their mode of action.

Medicinal Chemistry of Quinazolines as Anticancer Agents Targeting Tyrosine Kinases

Cancer is a large group of diseases that can affect any organ or body tissue due to the abnormal cellular growth with the unknown reasons. Many of the existing chemotherapeutic agents are highly toxic with a low level of selectivity. Additionally, they lead to development of therapeutic resistance. Hence, the development of targeted chemotherapeutic agents with low side effects and high selectivity is required for cancer treatment. Quinazoline is a vital scaffold well-known to be linked with several biological activities. The anticancer activity is one of the prominent biological activities of this scaffold. Several established anticancer quinazolines work by different mechanisms on the various molecular targets. The aim of this review is to present different features of medicinal chemistry as drug design, structure activity relationship, and mode of action of some targeted anticancer quinazoline derivatives. It gives comprehensive attention on the chemotherapeutic activity of quinazolines in the viewpoint of drug discovery and its development. This review provides panoramic view to the medicinal chemists for supporting their efforts to design and synthesize novel quinazolines as targeted chemotherapeutic agents.

One-Pot Synthesis of Isoxazole-Fused Tricyclic Quinazoline Alkaloid Derivatives via Intramolecular Cycloaddition of Propargyl-Substituted Methyl Azaarenes under Metal-Free Conditions

A practical method was developed for the convenient synthesis of isoxazole-fused tricyclic quinazoline alkaloids. This procedure accesses diverse isoxazole-fused tricyclic quinazoline alkaloids and their derivatives via intramolecular cycloaddition of methyl azaarenes with tert-butyl nitrite (TBN). In this method, TBN acts as the radical initiator and the source of N-O. Moreover, this protocol forms new C-N, C-C, and C-O bonds via sequence nitration and annulation in a one-pot process with broad substrate scope and functionalization of natural products.

Transition-metal-catalyzed synthesis of quinazolines: A review

Quinazolines are a class of nitrogen-containing heterocyclic compounds with broad-spectrum of pharmacological activities. Transition-metal-catalyzed reactions have emerged as reliable and indispensable tools for the synthesis of pharmaceuticals. These reactions provide new entries into pharmaceutical ingredients of continuously increasing complexity, and catalysis with these metals has streamlined the synthesis of several marketed drugs. The last few decades have witnessed a tremendous outburst of transition-metal-catalyzed reactions for the construction of quinazoline scaffolds. In this review, the progress achieved in the synthesis of quinazolines under transition metal-catalyzed conditions are summarized and reports from 2010 to date are covered. This is presented along with the mechanistic insights of each representative methodology. The advantages, limitations, and future perspectives of synthesis of quinazolines through such reactions are also discussed.

A Novel Ambroxol-Derived Tetrahydroquinazoline with a Potency against SARS-CoV-2 Proteins

We report synthesis of a novel 1,2,3,4-tetrahydroquinazoline derivative, named 2-(6,8-dibromo-3-(4-hydroxycyclohexyl)-1,2,3,4-tetrahydroquinazolin-2-yl)phenol (1), which was obtained from the hydrochloride of 4-((2-amino-3,5-dibromobenzyl)amino)cyclohexan-1-ol (ambroxol hydrochloride) and salicylaldehyde in EtOH. The resulting compound was produced in the form of colorless crystals of the composition 1∙0.5EtOH. The formation of the single product was confirmed by the IR and ¹H spectroscopy, single-crystal and powder X-ray diffraction, and elemental analysis. The molecule of 1 contains a chiral tertiary carbon of the 1,2,3,4-tetrahydropyrimidine fragment and the crystal structure of 1∙0.5EtOH is a racemate. Optical properties of 1∙0.5EtOH were revealed by UV-vis spectroscopy in MeOH and it was established that the compound absorbs exclusively in the UV region up to about 350 nm. 1∙0.5EtOH in MeOH exhibits dual emission and the emission spectra contains bands at about 340 and 446 nm upon excitation at 300 and 360 nm, respectively. The DFT calculations were performed to verify the structure as well as electronic and optical properties of 1. ADMET properties of the R-isomer of 1 were evaluated using the SwissADME, BOILED-Egg, and ProTox-II tools. As evidenced from the blue dot position in the BOILED-Egg plot, both human blood-brain barrier penetration and gastrointestinal absorption properties are positive with the positive PGP effect on the molecule. Molecular docking was applied to examine the influence of the structures of both R-isomer and S-isomer of 1 on a series of the SARS-CoV-2 proteins. According to the docking analysis results, both isomers of 1 were found to be active against all the applied SARS-CoV-2 proteins with the best binding affinities with Papain-like protease (PLpro) and nonstructural protein 3 (Nsp3_range 207-379-AMP). Ligand efficiency scores for both isomers of 1 inside the binding sites of the applied proteins were also revealed and compared with the initial ligands. Molecular dynamics simulations were also applied to evaluate the stability of complexes of both isomers with Papain-like protease (PLpro) and nonstructural protein 3 (Nsp3_range 207-379-AMP). The complex of the S-isomer with Papain-like protease (PLpro) was found to be highly unstable, while the other complexes are stable.

Medicinal Chemistry of Quinazolines as Analgesic and Anti-Inflammatory Agents

Quinazoline is an essential scaffold, known to be linked with various biological activities. Some of the prominent biological activities of this system are analgesic, anti-inflammatory, anti-hypertensive, anti-bacterial, anti-diabetic, anti-malarial, sedative–hypnotic, anti-histaminic, anti-cancer, anti-convulsant, anti-tubercular, and anti-viral activities. This diversity in the pharmacological response of the quinazoline system has encouraged medicinal chemists to study and discover this system and its multitude of potential against several biological activities. Many of these studies have successfully investigated the structure–activity relationship to explore the specific structural features of their biological targets. The developing understanding of quinazoline derivatives and their biological targets presents opportunities for the discovery of novel therapeutics. This review represents different aspects of medicinal chemistry, including drug design, structure–activity relationship, and the mode of action of some analgesic and anti-inflammatory quinazoline compounds. It pays comprehensive attention to the analgesic and anti-inflammatory activities of quinazolines from the viewpoint of drug discovery and its development.

2,3-Dihydro-Quinazolin-4(1H)-One as a Fluorescent Sensor for Hg2+ Ion and its Docking Studies in Cancer Treatment

The 2,3-dihydro-quinazolin-4(1H)-one was synthesised via the deployment of SBA-Pr-SO3H and its application was explored as a highly selective fluorescent sensor for Hg2+ ion; fluorescence intensity was decreased selectively by Hg2+ ions. Furthermore, this compound also indicated for its superb anti-interference ability among other ions. It is important to mention that this compound could be employed to detect a very low amount of Hg2+ ions, which are highly toxic and general contaminants. The docking study shows that the molecule, 2,3-dihydro-quinazolin-4(1H)-one, is a good inhibitor for the 5ACC enzyme.

Designing, Synthesis, and Anti-Breast Cancer Activity of a Series of New Quinazolin-4(1H)-one Derivatives

The inhibition of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) protein could be a promising treatment for breast cancer. In this regard, docking studies were accomplished on various functionalized organic molecules. Among them, several derivatives of quinazolin-4(1H)-one exhibited anti-breast cancer activity and satisfied the drug likeliness properties. Further, the in vitro inhibitory studies by a series of 2-(2-phenoxyquinolin-3-yl)-2,3-dihydroquinazolin-4(1H)-one molecules showed strong anti-cancer activity than the currently available drug, wortmannin. The MTT cytotoxicity assay was used to predict the anti-proliferative activity of these drugs against MCF-7 cancer cells by inhibiting the PIK3CA protein. The dose-dependent analysis showed a striking decrease in cancer cell viability at 24 h with inhibitory concentrations (IC₅₀ ) of 3b, 3c, 3d, 3f and 3m are 15±1, 17±1, 8±1, 10±1 and 60±1 (nanomoles), respectively. This is the first report in the literature on the inhibition of PIK3CA protein by quinazolinone derivatives that can be used in the treatment of cancer. Quinazolinone analogs have the potential to be safe and economically feasible scaffolds if they are produced using a chemical technique that is both straightforward and amenable to modification. From the cancer research perspective, this study can eventually offer better care for cancer patients.

Synthesis and Theoretical Studies of Biologically Active Thieno Nucleus Incorporated Tri and Tetracyclic Nitrogen Containing Heterocyclics Scaffolds via Suzuki Cross-Coupling Reaction

A new series of thieno nucleus embellished trinuclear (19, 20) and tetranuclear (21-24) nitrogen heteroaryl have been synthesized by the Suzuki cross-coupling reaction using bis(triphenylphosphine)palladium(II) dichloride. All the synthesized compounds were characterized by IR, ¹ H-NMR, ¹³ CNMR and Mass spectral properties. In vitro antibacterial studies of the synthesized compound were conducted using broth microdilution assay employing Gram-positive and Gram-negative strains and half-maximal inhibitory concentration (IC₅₀ ) was determined. The result showed that compound 20 possess best antibacterial activity against S. aureus and E. coli with IC₅₀ values of 60 μg mL^-1 and 90 μg mL^-1 . Further to determine the mode of antibacterial action, compounds 20 and 21 were examined for in vitro bacterial dehydrogenase inhibitory assay. To understand the binding affinity of the synthesized compounds, the docking study was performed in the bacterial dehydrogenase enzyme by AutoDock Vina software and structure was confirmed by Discovery Studio Visualizer. All the synthesized compounds were docked in a good manner within the active sites of the bacterial dehydrogenase enzyme and exhibited good binding energies.

Fast quinazolinone synthesis by combining enzymatic catalysis and photocatalysis

A fast and highly efficient method for the synthesis of functionalized quinazolinones by combining enzymatic catalysis and photocatalysis is reported. The α-Chymotrypsin catalyzed the cyclization of aldehyde and 2-aminobenzamide, which was subsequently followed by White LED-induced oxidation of 2-phenyl-2, 3-dihydroquinazolin-4(1H)-one to obtain quinazolinone. The reaction process was highly efficient with a reaction yield of 99% in just 2 h, and a wide range of quinazolinones could be synthesized. Furthermore, the plausible mechanism was investigated by control experiments and DFT calculations. This protocol provides an alternative synthetic route for the preparation of quinazolinone derivatives.

Synthesis, biological evaluation, and computational studies of some novel quinazoline derivatives as anticancer agents

A series of quinazolinone derivatives (7a-7h) were synthesized as antiproliferative agents. All compounds, were synthesized through three steps method and structurally evaluated by FTIR, ¹H-NMR, ¹³CNMR and Mass spectroscopy. Their cytotoxic activities were assessed using MTT protocol against three humans cancerous (MCF-7, A549 and 5637) and normal (MRC-5) cell lines. In addition, molecular docking and simulation studies of the synthesized compounds were performed to assessment their orientation, interaction mode against EGFR as plausible mechanism of quinazoline compounds as anticancer agents. The synthesized compounds mostly showed moderate activity against the three studied cell lines. They also indicated an appropriate selectivity against tumorigenic and non-tumorigenic cell line. The molecular docking results also confirmed biological activity. Most of the compounds fulfilled Lipinski rule. Collectively, these compounds with further modification can be considered as potent antiproliferative agents.

Synthesis and bioactivities evaluation of quinazolin-4(3H)-one derivatives as α-glucosidase inhibitors

The development of new antidiabetes agents is necessary to obtain optimal glycemic control and overcome its complications. Different quinazolin-4(3H)-one bearing phenoxy-acetamide derivatives (7a–r) were designed and synthesized to develop α-glucosidase inhibitors. All the synthesized derivatives were evaluated against α-glucosidase in vitro and among them, compound 7b showed the highest α-glucosidase inhibition with an IC50 of 14.4 µM, which was ∼53 times stronger than that of acarbose. The inhibition kinetic studies showed that the inhibitory mechanism of compound 7b was a competitive type towards α-glucosidase. Also, molecular docking studies analyzed the interaction between the most potent derivative and α-glucosidase. Current findings indicate the new potential of quinazolin-4(3H)-ones that could be used for the development of novel agents against diabetes mellitus.

Unexpected assembly machinery for 4(3H)-quinazolinone scaffold synthesis

4(3H)-quinazolinone is the core scaffold in more than 200 natural alkaloids and numerous drugs. Many chemosynthetic methodologies have been developed to generate it; however, investigation of its native enzymatic formation mechanism in fungi has been largely limited to fumiquinazolines, where the two nitrogen atoms come from anthranilate (N-1) and the α-NH₂ of amino acids (N-3). Here, via biochemical investigation of the chrysogine pathway, unexpected assembly machinery for 4(3H)-quinazolinone is unveiled, which involves a fungal two-module nonribosomal peptide synthase ftChyA with an unusual terminal condensation domain catalysing tripeptide formation; reveals that N-3 originates from the inorganic ammonium ions or the amide of L-Gln; demonstrates an unusual α-ketoglutarate-dependent dioxygenase ftChyM catalysis of the C-N bond oxidative cleavage of a tripeptide to form a dipeptide. Our study uncovers a unique release and tailoring mechanism for nonribosomal peptides and an alternative route for the synthesis of 4(3H)-quinazolinone scaffolds.