Synthesis and evaluation of some new 2-benzamido-3-(3, 4–substituted phenyl) acrylohydrazides for their in vitro antitubercular, antibacterial and antifungal activities

Abstract

Present work was designed to synthesize some new acrylohydrazides and evaluate new 2-benzamido-3-(3, 4–substituted phenyl)

acrylohydrazides for their in vitro antitubercular, antibacterial and antifungal activitivity. Synthesis of 4-(3, 4–disubstituted) benzylidine-

2-phenyloxazolin-5-ones(2 a-g) and 2-benzamido-3-(3, 4-substituted) phenyl acrylohydrazides (3a-g) were done. A total of 14

compounds were synthesized, purified and characterized by UV, FT-IR, 1H-NMR, 13C-NMR, Mass (ESI/MS) spectral data. Compounds

were screened for their in vitro antibacterial activity against S.aureus (Gram–positive bacteria), E.coli, P.vulgaris, P.aeruginosa (Gram–

negative bacteria) and antifungal activity against A. niger and C. albicans by agar plate disc diffusion method at a concentration of

50µg/disc. The antitubercular screening was carried out against M. tuberculosis H37Rv by Alamar Blue Assay method. It was found that

4-(3, 4-substituted) benzylidine-2-phenyl oxazol-5 (4H)-one 2(a-g) derivatives displayed better activity against bacteria and fungi than

mycobacteria. The conversion of intermediate 2(a-g) into acrylohydrazides 3(a-g) resulted in improved antitubercular activity, but still

showed moderate to mild antibacterial and antifungal action. Compounds 2e, 2d, 3e, 3d, possess common 4-hydroxy phenyl moiety and

are structurally similar, it was admirable that they showed disparity in antitubercular activity with respect to the 3-alkoxy substitution

in the same phenyl ring. It was concluded that substituted phenylacrylohydrazides exhibits considerable antitubercular activity and it

may be related to partition coefficient of compounds.