Anti-inflammatory, antibacterial and molecular docking studies of novel spiro-piperidine quinazolinone derivatives

A series of novel substituted quinazolinone derivatives was synthesized and characterized by 1H NMR and LC-MS spectral techniques. The overall results of the antibacterial tests showed that these compounds had better bacteriostatic activity against Gram-positive bacteria than their parent compounds. Furthermore, compounds 5f, 6b and 6f showed potent activity against Enterococcus faecalis (ATCC 51299), with MIC values <0.2 μg/mL. Compounds 4e, 5g, 5e and 6c showed excellent activity, with MIC values <0.4 μg/mL. Gram-negative bacteria Escherichia coli (ATCC 35218) and Klebsiella (ATCC 700603) are more resistant to lower concentrations of the synthesized compounds. The anti-inflammatory activities of the synthesized compounds were evaluated using the Carrageenan-induced rat Paw oedema method and ibuprofen as a standard drug. Compounds 4a and 4b exhibited good activity. Additionally, docking stimulations were performed to position compounds 4e, 4g, 5e, 5f, 6a and 6f into the EGFR kinase domain and human oestrogen receptor active site to determine probable binding information. This study indicated that compounds 6a and 6f have significant binding activities of 58.36 and 57.67 kJ mol−1, respectively.