Abstract
Starting from 4-(6,8-dibromo-2-phenyl-4-oxo-(4
H)-quinazolin-3-yl)-benzoic acid ethyl ester (
II) and its acid hydrazide
III, a new series of Schiff bases
IV and their cyclized products, thiazolidinones
V, oxadiazole
VIII, pyrazoles
X–
XII, pyrroles
XIII–
XV and other related products were synthesized. These compounds were screened for their anti-bacterial activity against Gram-positive bacteria (
Staphylococcus aureus,
Legionella monocytogenes and
Bacillus cereus) and Gram-negative bacteria (
Escherichia coli,
Pseudomonas aeruginosa and
Salmonella typhimurium) and anti-fungal activity (
Candida albicans and
Aspergillus flavus) using paper disc diffusion technique. The minimum inhibitory concentrations (MICs) of the compounds were also determined by agar streak dilution method. Among the synthesized compounds 2-(4-(2-phenyl-6,8-dibromo-4-oxo-(4
H)quinazolin-3-yl)-
N-ethylamido benzoic acid hydrazide
VIIa was found to exhibits the most potent in vitro anti-microbial activity with the MICs of 1.56, 3.125, 1.56, 25, 25 and 25 μg/ml against
E. coli,
S. typhimurium,
L. monocytogenes,
S. aureus,
P. aeruginosa, and
B. cereus respectively. Compound 2-(4-(2-phenyl-6,8-dibromo-4-oxo-(4
H)quinazolin-3-yl)-
N-methyl thioamido benzoic acid hydrazide
VIIc was found to exhibit the most potent in vitro anti-fungal activity with MICs 0.78 and 0.097 μg/ml against C. albicans and
A. flavus.
Compound
VIIa was found to exhibit the most potent in vitro anti-microbial activity with the MICs of 1.56, 3.125, 1.56, 25, 25 and 25 μg/ml against
E. coli, S. typhimurium, L. monocytogenes, S. aureus, P. aeruginosa, and
B. cereus respectively. Compound
VIIc showed pronounced in vitro anti-fungal activity with MICs of 0.78 and 0.097 μg/ml against
C. albicans and
A. flavus.
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