6- bromo-2-(4-chlorophenyl)quinazolin-4(3H)-one derivatives 2-7 were synthesized.. The synthesized compounds were evaluated for their anti-microbial activity using the agar diffusion technique . The tested compounds were evaluated against, Gram +ve bacteria , Gram -ve bacteria, Yeast and Filamentous Fungus. Minimum inhibitory concentration (MIC) was made in vitro for compounds which showed antimicrobial activity. Compound 3b has broad spectrum activity against Gram +ve bacteria, Gram -ve bacteria, Yeast and Filamentous Fungus with MICs 150, 150, 75, 312, 625 and 625 µg/mL against (Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 3555, Escherichia coli ATCC 23282 Pseudomonas aeruginosa ATCC 10145, Candida albicans IMRU …show more content…
Introduction Resistant bacterial strains has become a serious problem . This is due to false diagnosis and the excessive use of antibiotic [2,3]. This encourage us to search for new antimicrobial agents. Quinazolinones are heterocycles that are of great interest due to their biological activities such as anticancer [4-8], anti-psychotic , anti-inflammatory [10,12], antifungal [12-14] and antimicrobial activities[15-18].
Many 2,3 disubstituted quinazolinone derivatives have good antimicrobial and antifungal activities [19,20]. On the other hand substitution at 3rd position of bromo quinazolinone derivatives with phenyl ring show potential antimicrobial and antifungal activities [21,22]. Chacones, pyrazole, isoxazole and thiopyrimidine have antibacterial and antifungal activities [23-26].
Continuation of our research program which aim to synthesis of new biologically active quinazolin-4-one derivatives [4-8, 22], we synthesized new bromo quinazolinone derivatives substituted at 3rd position with chalcones,pyrazole, isoxazole or thio pyrimidine moiety bearing para chloro phenyl moiety at position 2.
2. Results and discussion
2.1. …show more content…
6-bromo quinazolinone derivatives bearing para chloro phenyl moiety at position 2 and substituted at 3rd position with 4-chalcone moiety bearing 4-choro phenyl 3b show remarkable antimicrobial, anti yeast and anti fungal activity . 4-chalcone moiety bearing 3,4,5-trimethoxyphenyl 3d show potent activity against Gram -ve bacteria. On the other hand 4-chalcone moiety having phenyl or furan-2-yl abolish antimicrobial activity but have potent anti yeast and anti fungal activity. While substitution with 4-nitrophenyl at the same position afford compound 3c with no antimicrobial or antifungal activity. Substituted at 3rd position with 5-phenyl- pyrazol or 1-acetyl-5-phenyl moiety give compound 4a, 5a respectively with promising anti yeast and anti fungal activity. While substitution at the same position with 1-acetyl-(4-chlorophenyl) moiety give 5b which have potent activity against Gram +ve bacteria. Compounds 6a,b and 7a,b with dihydro isoxazol or thioxo-tetrahydro pyrimidinyl moiety repectively at 3rd position of quinazolinone nucleus has neither antimicrobial nor anti fungal