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Objective: The proposed study is an attempt to determine antibacterial activity of synthesized novel 1-substituted-3-(4-oxo-2-phenylquinazolin-3(4H)-yl) urea and thiourea analogues as potent antibacterials against S. aureus and E. coli bacteria. Methods: The present study reports new series of 1-substituted-3-(4-oxo-2-phenylquinazolin-3(4H)-yl) urea and thiourea derivatives as potent antibacterial agents. Reagents used in the present study were of synthetic grade and solvents were used after distillation. Novel quinazolinone analogues were synthesized by considering substitution pattern, characterization of the synthesized analogues was performed using various techniques like Thin layer chromatography, Melting point, Infrared spectroscopy, Proton NMR spectrometry and Mass spectrometry. TLC of the synthesized analogues was carried out by using (toluene: methanol in the ratio 2:1), melting point was found by open capillary method, IR spectrum was recorded on JASCO V-530, 1H NMR was recorded on Bruker Avance Spectrometer and Mass spectra were obtained from G6460A, triple quadrupole/MS/MS system. In vitro antibacterial activity was performed against S. aureus and E. coli. Results: Six derivatives of quinazolinone analogues were synthesized. The structures of 1-substituted-3-(4-oxo-2-phenylquinazolin-3(4H)-yl) urea and thiourea derivatives were confirmed by physical and spectral analysis. Synthesized molecules showed Rf of 0.45-0.80 in toluene: methanol mobile phase, melting point was carried out by open capillary method and were in range of 90-210 ° C, IR spectrum was recorded in range of 14000-400 cm-1and showed characteristic peaks of NH and of C-O-NH, 1H NMR of the compounds was distinct to confirm structures with delta values in the range of 7.53-11.960, Mass spectra proved parent peaks of synthesized compounds confirming molecular weight. The compounds were assayed for antibacterial activity against S. aureus and E. coli using ciprofloxacin as standard. The synthesized analogues have shown good yield and comparable antibacterial. Conclusion: The present study delivers a convenient and efficient protocol for the quinazolinone analogues synthesis.

1-substituted phenyl quinazolinones analogues were designed by performing molecular modelling studies against tumour necrosis factor alpha converting enzyme (TACE PDB Id: 2A8H) and in-silico Lipinski properties for drug likeness. From QSAR studies, it could be concluded that the urea and thiourea groups play a crucial role in enhancing cytotoxic effects of compounds. Substitution of halogens like trifluoromethyl, chloro and allylic functional group may enhance the cytotoxic effect of urea and thiourea analogues. Substitution of phenyl and benzoyl ring were not found effective against cancer. Also, the presence of substituted aromatic ring at position 3 and methyl or thiol group at position 2 are essential for antimicrobial activities of quinazolinone. The synthesized compounds were characterized by TLC, MP, IR, NMR and Mass spectral data and were screened for their anticancer activity. The in vitro anticancer studies were performed on six selected compounds using MTT assay against MDA MB-231 cell line using paclitaxel as a standard. The synthesized 1-substituted -3-(4-oxo-2-phenylquinazolin-3(4h)-yl) urea and thiourea derivatives exhibited significant anticancer activities.

In the last decade, quinazoline was one of the most explored scaffolds by researchers around the globe in medicinal chemistry. Its unique structural features provide a wide range of substitutions on nitrogen and carbonyl groups. In the current situation of COVID-19, hydroxychloroquine an antimalarial drug of the quinoline category was used for the treatment of severe infections. Various substitution patterns, hybrids, and conjugates of quinazoline have been developed and studied for various pharmacological activities like anticancer, anti-inflammatory, antimalarial, antitubercular, etc. The scaffold can be considered as a potential molecule for various pharmacological activities especially as antimicrobial and antihypertensive. The current review aims to study, physicochemical properties, chemistry, and pharmacological profile of quinazoline.

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