Abstract
The aim of this study was to develop novel isoniazid derivatives, which can be utilized as antitubercular agents. The compounds were synthesized by reaction between the hydrazine unit of isoniazid with an appropriate lipophilic moiety. The compounds obtained were characterized on the basis of their melting points, R-f value, Fourier Transform Infra Red (FTIR) Spectra, H-1-Nuclear Magnetic Resonance (H-1-NMR) Spectra, C-13- Nuclear Magnetic Resonance (C-13-NMR) Spectra, Elemetal Analysis, and the Mass spectra. The novel compounds were assessed for their anti-tubercular activity by reported method against four strains of the Mycobacterium. The minimum inhibitory concentration of the active compounds was also determined. The anti-tubercular activity data revealed that most of the compounds have higher MIC values as compared to the standard drug isoniazid. Two compounds, namely 3b and 3c, exhibited very good anti-tubercular activity against all four strains of the Mycobacterium, which was comparable to the standard drug isoniazid. It has been concluded that the incorporation of a lipophilic chain at the position-2 of the pyridazine ring along with a halogen group, preferably a fluorine atom, at the p-position of the phenyl ring in this series of compounds increase the anti-tubercular activity of the compounds. However, this assumption cannot be generalized because in the present study the anti-tubercular activity was assessed against four strains of Mycobacterium. Accordingly, further studies are recommended to assess the anti-tubercular activity of these two compounds, 3b and 3c, against other strains of the Mycobacterium.