Synthesis and evaluation of novel hydroxamic acids as potent antibacterial and antifungal agents

Novel hydroxamic acids (6-10 and 13, 14) were synthesized by reaction of substituted benzoyl chorides (1-3) with substituted hydroxylamine hydrochlorides (4, 5) in presence of aqueous potassium carbonate in diethyl ether at 00C temperature. The new products were purified by silica gel column chromatography and characterized by infrared (IR), proton nuclear magnetic resonance (1H NMR) spectroscopic data, and elemental analysis. All the compounds were evaluated for their antibacterial and antifungal potential by the cup-plate method. From the antibacterial screening it was observed that the compounds, 6, 9, 13 and 14 shows good antibacterial activity against Staphylococcus aureus (zone of inhibition,10-15 mm) as compared to standard streptomycin (zone of inhibition, 18 mm), and Escherichia coli (zone of inhibition,14-16 mm) as compared to streptomycin (zone of inhibition, 22 mm). Fungicidal screening data also revealed that compounds, 6, 7, 8, 9 and 14 imparted maximum activity against Aspergillus niger (zone of inhibition, 10-15 mm) as compared to standard griesofulvin (zone of inhibition, 17 mm), whereas compounds 7, 8, 9, 13 and 14 showed moderate activity against Candida albicans (zone of inhibition, 10-15 mm) as compared to griesofulvin (zone of inhibition, 20 mm).