Synthesis of Schiff bases of 2-amino-5-aryl-1, 3, 4-oxadiazoles and their evaluation for antimicrobial activities

Abstract

Twenty Schiff bases of 2-amino-5-aryl-1,3,4-oxadiazoles have been synthesized with different aromatic aldehydes. The structures of the compounds were confirmed by nitrogen analysis, IR and 13 C-NMR spectral data. The antibacterial** properties of the compounds were investigated against Proteus mirabilis (MTCC-425), Pseudomonas aeruginosa (MTCC-424), Bacillus subtilis (MTCC-619) and Staphylococcus aureus (MTCC-96) using the broth dilution method. The most active compounds were 4c (64 m mg/ml), 4f (68 m mg/ml), 4m (64 m mg/ml) and 4q (62 m mg/ml). The antifungal** screening of the compounds were carried out using Aspergillus niger (MTCC-1344) and Candida albicans (MTCC-227) using the broth dilution method. Active compounds were 4g (52 m mg/ml), 4h (56 m mg/ml), 4l (60 m mg/ml), 4m (58 m mg/ml).

Oxadiazoles

“…The corresponding MICs are in the range 52-60 mg ml À1 . The biocidal activities of these compounds were attributed to the toxophoric C¼N linkage [527]. The mixture of sodium acetate, bromine, and glacial acetic acid has also been used to prepare several antibacterial 1,2-bis(1,3,4-oxadiazol-2-yl)ethanes 651 from the corresponding diacylhydrazones 650 (Scheme 13.207) [528].…”

Synthesis and Evaluation of Anticancer Activity of 1, 3, 4-Oxadiazole Derivatives against Ehrlich Ascites Carcinoma Bearing Mice and Their Correlation with Histopathology of Liver

“…Normal saline 5ml/kg; body weight per day was administered in-group II (EAC control). The synthesized compounds (4A-4G were administered at dose of 25,20,20,25,20,20, 25mg mg/kg; body weight/day) and the standard drug 5-Fluorouracil (20 mg/kg; body weight/day) was administered in groups (III-IX) and (X) respectively for 7 days intraperitoneally at 24 hr interval. Thus 7 doses of the drug are administered to each mouse in the test group.…”

Synthesis and antimicrobial activity of some new 3–[5-(4-substituted) phenyl-1,3,4-oxadiazole-2yl]-2- styrylquinazoline-4(3H)-ones

“…The increased antimicrobial activity obtained by placing a styryl moiety at the second position has also been reported. In our research we found that oxadiazole and substituted oxadiazole itself possessed antibacterial and antifungal activities (Mishra et al, 2005). In an effort to observe the synergistic effect of both of these effects we synthesized new 4(3H)-qunazolinone analogues incorporating the styryl moiety and substituted oxadiazole at the second and third position of 4(3H)-qunazolinone, respectively.…”