Design, Synthesis, and Structure–Activity Relationships of Novel 1-(Substituted)-2-Methyl-3-(4-Oxo-2-Methylquinazolin-3(4H)-yl) Isothioureas for Their Anti-HIV and Antibacterial Activities.

In this study, a novel quinazolinone analogue was designed and synthesized by substituting the thiourea group and phenyl ring at N-3 and C-2 positions of the quinazoline ring, respectively. The prepared analogue was tested for its antibacterial, antitubercular and anti-HIV potencies. The agar dilution method was used to test the antibacterial potency of entire prepared derivatives against various gram-positive and gram-negative microorganism strains. Compound 1-(3-chlorophenyl)-2-methyl-3-(4-oxo-2-methylquinazolin-3(4H)-yl)isothioureas (Xi) shown most potent activity against Klebsiella pneumoniae, Proteus vulgaris, and Staphylococcus epidermidis at 1.6 µg/mL. The compound (Xi) exhibited the antitubercular activity at the minimum microgram of 6.25 µg/mL and anti-HIV activity at 1.17 µg/mL against HIV1 and HIV2. The compound (Xi) offers a potential lead for further optimization and development to new antitubercular and anti-HIV agents. The results obtained from this study confirm that the synthesized and biologically evaluated quinazolines showed promising antimicrobial, antitubercular, and anti-HIV activities and new scaffolds for antimicrobial activity. [ABSTRACT FROM AUTHOR]