Structural and Biological Activity Study of (E)-N’- (5-Chloro-2-Hydroxybenzylidene)Nicotinohydrazide) [H2L] and some of its Divalent Metal Complexes

Abstract

Nicotinic acid hydrazide and 2-hydroxyl-5-chlorobenzaldehyde were condensed at 80 o C to form an ONO coordination pattern ligand (H 2 L). The structure of the ligand was elucidated by using 1 H NMR, 13C NMR, COSY, HSQC, CHN analyzer, ESI mass spectrometry and IR, Thereafter, five metal complexes [Cu(II), Fe(II), Zn(II), Mn(II) and Ni(II)] of the ligand were synthesized and their structural elucidation were achieved by using elemental analysis, infrared, EPR, molar conductivity and powder X-ray diffraction studies. Structural geometries of some of the compounds were predicted. Based on the analysis, octahedral geometry was suggested for the complexes. In vitro anti tubercular activity study of the ligand and the metal complexes were evaluated against Mycobacterium tuberculosis, H37Rv, by using micro-diluted method. The results obtained (H 2 L-MIC = 0.86 µg/mL), (CuL-MIC = 0.64 µg/mL), (FeL-MIC = 0.77 µg/mL), (ZnL-MIC = 0.69 µg/mL), (MnL-MIC = 1.12 µg/mL) and (NiL-MIC = 0.92 µg/mL) revealed that all the compounds except (MnL-MIC = 1.12 µg/mL) possess better activity when compared with one of the first line drug (isoniazid) (INH-MIC = 0.9 µg/mL). H 2 Lexhibited higher anti tubercular activity with MIC value of 0.86 µg/mL. However, the metal complexes displayed higher cytoxicity but were found to be non-significant different (P < 0.05) to is on isoniazid drug.

Synthesis, characterisation and antibacterial study of copper(ii) complexes of new benzylacetone-benzoylhydrazone and its <i>para</i>-nitro and <i>para</i>-hydroxy substituted analogues

“…Hydrazones and their metal complexes have remained an interesting area of studies for the Inorganic and bioinorganic chemist in the last decades, due to their biological activity and industrial applications (Olurotimi et al, 2017;Emami et al, 2021;Argibay et al, 2022). Hydrazones are formed by condensation reactions (Figure 1) between hydrazine derivatives often called hydrazides, and carbonyl compounds (aldehyde or ketone) (El-Gammar, 2015;Ajayeoba et al, 2021;Argibay et al, 2022).…”