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.
Keywords: Azetidinone, Schiff bases, Synthesis,
Antimicrobial activity, Antitubercular activity.
