Synthesis, Antimicrobial and Antitubercular Activities of Some Novel Trihydroxy Benzamido Azetidin-2-one Derivatives

Purpose: To synthesize and characterize novel trihydroxy benzamido azetidin-2-one derivatives and screen them for antimicrobial and antitubercular activities. Methods: A series of novel 4-aryl-3-chloro-N-(3,4,5-trihydroxy benzamido)-2-azetidinones, 3a-o, were synthesized by reacting various Schiff bases of galloyl hydrazide, 2a-o, with chloroacetyl chloride in the presence of dioxan and triethylamine. Schiff bases of galloyl hydrazide, 2a-o, were synthesized from galloyl hydrazide. The newly synthesized compounds were characterized by infrared spectroscopy (IR), mass spectroscopy (MS) and proton nuclear magnetic spectroscopy (1H NMR) and elemental analysis; they were also screened for in vitro antibacterial, antifungal and antitubercular activities. Ciprofloxacin and ketoconazole were used as reference standards for antibacterial and antifungal activities, respectively, while isoniazid was used as reference standard for antitubercular activity. Results: Compounds 3f, 3g and 3o with chlorophenyl group and compound 3k with 4-dimethyl amino phenyl group exhibited good antimicrobial activity. Also, compounds 3f, 3g, 3k and 3o showed antitubercular activity with minimum inhibitory concentration (MIC) values equivalent to the standard drug (isoniazid). MIC values of 3f, 3g, 3k and 3o were 0.76, 0.57.0.62 and 0.83 µg/ml, respectively, while the MIC of isoniazid was 0.56. Conclusion: We report the successful synthesis, spectral characterization, as well as in vitro antimicrobial and antitubercular evaluation of a series of novel trihydroxy benzamido azetidin-2-one derivatives. The work shows the emergence of new antimicrobial and antitubercular compounds