Synthesis, antimicrobial evaluation and molecular modelling of novel sulfonamides carrying a biologically active quinazoline nucleus

A novel series of quinazolines 5-10, triazoloquinazolines 11-17 and triazinoquinazoline 19 bearing a biologically active sulfonamide moiety were synthesized, utilizing methyl 2-isothiocyanato benzoate 2. Some of the newly synthesized compounds revealed promising bacterial growth inhibition, compared with the ampicillin, as the reference drug. A LigandScout approach-generated pharmacophore model for the Staph aureus bacteria growth inhibition was done. The degree of fitting of the test set compounds (3, 4, 6, 8, 11, 17) to the generated hypothetical model revealed a qualitative measure of the more or less microbial inhibition of Staphylococcus aureus. Compounds (7, 8, 10, 12, 15, 17 and 22), which revealed significant activity, are able to effectively satisfy the proposed pharmacophore geometry, using the energy accessible conformers (E (conf) < 20 kcal/mol).