Microwave-assisted synthesis, structural characterization, DFT studies, antibacterial and antioxidant activity of 2-methyl-4-oxo-1,2,3,4-tetrahydroquinazoline-2-carboxylic acid

• Published in: Journal of molecular structure Vol. 1155; pp. 610 - 622
• Main Authors: Obafemi, Craig A., Fadare, Olatomide A., Jasinski, Jerry P., Millikan, Sean P., Obuotor, Efere M., Iwalewa, Ezekiel O., Famuyiwa, Samson O., Sanusi, Kayode, Yilmaz, Yusuf, Ceylan, Ümit
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.03.2018
• Subjects: Antimicrobial studies; Antioxidant activity; DFT studies; Fragmentation pattern; Single crystal X-ray structure; Tetrahydro-4-quinazolinone-2-carboxylic acid; Single crystal X-ray structure; Fragmentation pattern; DFT studies; Antioxidant activity; Tetrahydro-4-quinazolinone-2-carboxylic acid; Antimicrobial studies
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2017.11.018

In the present study a new tetrahydroquinazoline-2-carboxylic, C10H10N2O3, 1′, was synthesized and its structure was characterized by elemental analysis, IR, 1H NMR, 13C NMR data and high-resolution mass spectrometry. The spectral results are in line with the proposed structure. Single crystal X-ray structural analysis of the compound showed that the crystal structure adopts a monoclinic space group P21/c, with the packing of the molecule stabilized by CO … …HO, NH … ….OCO intermolecular hydrogen bonding. The theoretical geometrical parameters of the compound have been calculated using density functional (DFT) and time-dependent density functional (TD-DFT) theory methods and have been used to predict the thermodynamic one-electron redox potential and the electronic absorption property of the compound. The theoretical characterization matched the experimental measurements, showing a good correlation. The calculated HOMO-LUMO gap (4.79 eV) suggests that compound 1′ could be a potential antioxidant. The synthesized compound was screened for its in vitro antimicrobial activity against selected bacterial strains and antioxidant activity using the TAC, FRAP, NO and ABTS models. In vitro antioxidant activity of 1' showed a moderate activity, but weaker scavenging activity than the standards of ascorbic acid and trolox. Results of the antibacterial activity of the tested compound showed that it possesses a higher activity against Bacillus anthracis, Bacillus cereus, Bacillus polymyxa, Bacillus subtilis and Staphylococcus aureus than the two standard drugs, streptomycin and tetracycline, and better activity than tetracycline against Escherichia coli. •A tetrahydroquinazoline-2-carboxylic acid has been synthesized as possible antioxidant agent.•Its chemical structure was studied by X-ray, MS, IR and NMR.•The crystal packing is stabilized by intermolecular non-covalent interactions.•The DFT theoretical results were compared with the experimental results.•The in-vitro antioxidant and antimicrobial activities of the prepared compound have been evaluated.