Synthesis, antibacterial and antifungal activities of 6,5 fused steroidal oxazoles in cholestane series

Herein, we report a convenient one-pot synthesis of 2′-amino-5α-cholest-6-eno [6,5-d] oxazole derivatives (4–6). The synthesis involves the reaction of cholestan-6-ones (1–3) with urea and iodine. The structural assignment of the products was confirmed on the basis of IR, 1H NMR, 13C NMR, and Mass spectra which find support from comparison with authentic samples. The antibacterial activity of all the synthesized compounds was tested in vitro by the disk diffusion assay against three Gram-positive and three Gram-negative strains of bacteria. All the synthesized compounds were also tested for their inhibitory action against five strains of fungus and then the minimum inhibitory concentration (MIC) of all the synthesized compounds were determined. Compounds (4–6) showed inhibitory action against both types of the bacteria (Gram-positive and Gram-negative) and five strains of fungi are good antimicrobial agents. Chloramphenicol (30 μg) was used as standard drug in case of bacteria and nystatin was used as a standard drug in case of fungi.

Graphical abstractWe have investigated the antibacterial and antifungal activity of 2′-amino-5α-cholest-6-eno [6,5-d] oxazole derivatives (4–6) prepared by refluxing cholestan-6-ones (1–3) with urea and iodine in ethanol. The structures of the compounds were established by means of their IR, 1H NMR, 13C NMR, FAB mass spectra and micro analytical data. The antibacterial activity of all the synthesized compounds was tested in vitro by the disk diffusion assay against three Gram-positive and three Gram-negative strains of bacteria. All the synthesized compounds were also tested for their inhibitory action against five strains of fungus and then the minimum inhibitory concentration (MIC) of all the synthesized compounds were determined. Chloramphenicol (30 μg) was used as standard drug in case of bacteria and nystatin was used as a standard drug in case of fungi.Figure optionsDownload full-size imageDownload as PowerPoint slide