Abstract:
Thiazole, the heterocyclic compound is an important scaffold of azaheterocycles family.
Heterocyclic nucleus containing thiazole Schiff bases imparts an important function in
medicinal chemistry and serves as a key template for the development of various
therapeutic agents. In our present work, three thiazole Schiff base derivatives containing
quinoline moieties 1b-3b were synthesized by two step reactions. Firstly, three
thiosemicarbazone derivatives la-3a were synthesized using aldehydes substituted
quinoline and thiosemicarbazide. Cyclization of la-3a with 3-chloroacetylacetone
afforded the corresponding thiazoles Schiff bases 1b-3b. The synthesized analogs
characterization was elucidated by spectral analyses (IR, 1H NMR, 13C NMR, COSY,
HSQC and HMBC). All the synthesized compounds were screened for their antimicrobial
activity towards three gram-positive bacteria Bacillus Cereus, Staphylococcus aureus and
Bacillus magaterium, three gram-negative bacteria Klebsiella pneumonia, Pseudomonas
aeruginosa and Escherichia coli and two fungal strains Trichoderma harzianum and
Aspergillus niger were used in this study revealed that some compounds displayed
moderate to good antimicrobial activities compared to standard Ampicillin &
Amphotericin B in Agar disc diffusion technique. Compounds 1b & 3b revealed
comparable antibacterial activities against S. aureus, B. Cereus, K. pneumonia and E. coli,
compound 2b showed potential antibacterial activities against S. aureus, K. pneumonia,
and E. coli with standard ampicillin. In antifungal screening, compounds 1b & 3b showed
moderate to potential antifungal activities against the fungi Aspergillus niger with
standard amphotericin b. From our research, we observed that compounds 1b & 3b might
be used as potential antibacterial and antifungal drugs in future.
