C. U. Dueke-Eze
Background: The increasing reports of resistance of Mycobacterium tuberculosis (M.TB) to the classical anti-tuberculosis drugs and co-morbidity of tuberculosis (TB) with HIV infection pose challenges for effective control of TB. Development of new compounds with anti-TB effect to combat the resistance is highly desirable.Objective: Metal complexes represent a major investigational compound. The presence of metal ion in these compounds will make it difficult for the bacteria to develop resistance to as its mode of action will be different from the existing anti-TB agents. The goal of this study is to probe the in vitro antituberculosis activity of some halogenated benzylidene Schiff base metal complexes.Materials and methods: The Schiff bases were synthesized by condensation of isonicotinic acid hydrazide (INH) with some halogenated benzaldehydes and then reacted with CuCl2.2H2O and CoCl2.6H2O to obtain the metal complexes. The compounds were characterized by elemental analysis, infrared (IR), nuclear magnetic resonance (NMR), electronic absorption and molar conductivity. The synthesized compounds were evaluated for their in-vitro anti-tuberculosis activity against standard strain (M.TB H37Rv) using the proportion method and isoniazid (INH) as a reference compound.Results: The Schiff bases reacted as bidentate ligands to yield complexes of 1:1 or 1:2 (M: L) ratio. All the complexes are assigned either octahedral or square planar geometry based on the electronic spectra. The complexes showed enhanced in-vitro anti-tuberculosis activity against mycobacterium tuberculosis H37RV compared to the free ligands and reference compound (INH). Conclusion: The results demonstrate that compounds with metal ion can display strong anti-TB activity making them suitable for further exploration.