Anti-bacterial activity.

A series of 1-(substituted -2-oxoquinolin-1(2H)-yl) urea and thiourea have been synthesized by using coumarin derivatives and semicarbazide in presence of ethanol as a solvent. Coumarin derivatives were prepared via pechmann condensation by adding a mixture of substituted phenol and ethyl acetoacetate in concentrated sulfuric acid. Coumarin derivatives then subjected to condensation with semicarbazide and thiosemicarbazide. The structure of all these synthesized compounds has been established on the basis of chemical transformation, IR and 1HNMR spectral studies. Synthesized compounds are showing amazing antibacterial activity for common food borne pathogens such as Escherichia coli, Shigella flexneri, Staphylococcus aureus, and Bacillus cereus.

A series of novel triazole fused thienopyrimidine derivatives are synthesized by Gewald reaction, which are well characterized by IR, 1HNMR, 13CNMR and Mass spectral analysis. These compounds are screened for their in vitro anti-tubercular and antibacterial activities. Most of these compounds exhibited MIC values in the range of 20 – 100 µM against Mycobacterium tuberculosis H37Rv. In the series, compound 5c was most active with MIC 20 µM. Furthermore, the title compounds were screened for antibacterial activity against Staphylococcus aureus ATCC 29213 (gram positive) and Escherichia coli ATCC 25922 (gram negative) bacteria. Some of these compounds exhibited MIC values in the range 8 - 64µM. Compound 5c was found to be the most active with an MIC of 5 and 8µM respectively.

In the present study, a series of novel quinazoline derivatives were synthesized by condensation with different aromatic amines via cyclized intermediate 2-phenyl-1, 3-benzoxazin-4-one.The chemical structures were confirmed by means of IR, H1 NMR. These compounds were screened for anti-bacterial (Staphylococcus aureus ATCC-9144, Escherichia coli ATCC-25922, activities by paper disc diffusion technique. The potency of antibiotic content in samples can be determined by chemical, physical or biological means. An assay was performed to determine the ability of an antibiotic to kill or inhibit the growth of living microorganism. The inhibition of microbial growth under standardized conditions may be utilized for demonstrating the therapeutic efficacy of drugs. Microorganisms employed in biological assay were of various types of bacteria for amino acid & antibiotics, fungi for vitamins & trace elements. The synthesized compounds were evaluated for anti-bacterial activity. Some of these synthesized compounds show significant anti-bacterial activity.