KO Ogunniran , MA Mesubi , JA Adekoya , OO Siyanbola , AI Inegbinebor , OO Ojo , AE Adedapo , A Edobor-Osoh and T Narender
Keywords: X-ray, hydrazones, metal complexes, electron spin resonance, thermogravimetric, crystallographic, antitubercular agents
Abstract: The cold condensation reaction of nicotinic acid hydrazide and 5-bromo-2-hydoxylbenzaldehyde to form a tridentate schiff base hydrazone ligand (H2L3) was studied. The prepared ligand was characterized using CHN analyxer, ESI mass spectrometry, IR, 1H NMR, 13CNMR and 2D NMR such as COSY and HSQC. Thereafter, five novel metal complexes [Pt(II), Zn(II), Mn(II), Ni(II) and Mo(V)] of the hydrazone ligand were synthesized and characterized based on conductivity measurements, CHN analysis, AAS, magnetic measurements, UV/Wis, IR, ESR and TGA/DTA study. The proposed structures of the metal complexes were further supported with the use of powder X-ray analysis. Antitubercular activity study of the compounds was evaluated against Mycobacterium tuberculosis H37Rv by using microdiluted method. The study revealed that H2L3 exhibited promising anti-tubercular activity with MIC value of 0.82 ug/mL. Also, metal complexes ([pt(H2L3)cl]- 0.88 ug/mL, [mn(H2L3)(CH3COO)2]- 0.78 ug/mL, [Zn(H2L3)(CH3COO)2H2O]- 0.62 ug/mL and [Ni(H2L3)(Cl)2]H2O- 1.19 ug/mL) exhibited significant inhibition as compared to the standard drug (isoniazid- 0.91 ug/mL). Complex 2 and 3 with coordinated acetates showed two folds inhibition than standard isoniazid drug . Howevver, complex 5 with coordinated chlorine atom displayed atom displayed lower inhibition when compared to isoniazid.
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