Synthesis, Structural Characterization, Catalytic, Biological and α-Glucosidase Inhibitory Studies of Metal Complexes with Flavone Derivatives

Heterocyclic compounds, in particular oxygen-containing heterocyclic compounds, are of special interest to medicinal chemists because of their unusual biological properties. In the present study, the highly conjugated nitrogen heterocyclic scaffold comprised of flavone derivative with metal acetates to form metal chelates of the type [MIIL(OAc)2], flavone analogues (L); M=Co2+, Zn2+, Cu2+ and Ni2+. The above title compounds were characterized using composition analysis o fCHN and spectroscopic techniques. Based on spectroscopic and analytical measurements confirmed that square planar arrangements for the Co2+, Zn2+, Cu2+ and Ni2+ complexes. Antimicrobial efficacy of prepared complexes were assessed against A.flavus, A.niger, B.subtilis, E. coli, C. albicans and S.aureus. The anti-mycobacterial (H37Rv) efficacy of flavone analogues and its complexes were screened using MABA approach and compared with standard. The acetylcholinesterase (AChE) inhibitory effect of the ligand was examined to find out the therapeutic efficiency of compound in the treatment of neurodegenerative disorders. The synthesized ligand exhibited selective inhibition (AChE & BuChe) values (IC50:0.20(flavone analogue), 2.41 (Rivastigmine) and 3.01 µM (Galantamine), respectively. Further, the in vitro ant-inflammatory efficiency of metal chelates were performed with the help of egg albumin method. The α-glucosidase inhibition activity was also carried out for the prepared metal complexes.

Synthesis, characterization and antimicrobial activity of copper(II) Schiff base adducts of some p-substituted aniline Schiff bases

The synthesis, characterization and antimicrobial activity of Cu(II) complexes of some p-substituted aniline Schiff base ligands have been carried out. The Schiff bases were obtained from salicylaldehyde and o-vanillin. The Cu(II) complexes have been characterized by elemental analysis, conductivity measurement, infrared and electronic spectral data. The complexes were obtained either as metal chelates [Cu(L)2] or Schiff base adducts (CuCl2.2LH).xH2O. The metal chelates were non-electrolytes while the Schiff base adducts exhibited 1:1 or 2:1 electrolytes in methanol. The Cu(II) complexes exhibited slight antimicrobial activity against Escherichia coli ATCC® 8739™*, Staphylococcus aureus subsp. aureus ATCC® 6538™*, Bacillus subtilis subsp. spizizenii ATCC® 6633™* and Candida albicans ATCC® 2091™*. The complexes exhibited significant antifungal activity. KEY WORDS: Metal Chelates, Schiff bases, Adducts, Cu(II) complexes, Salicylaldimines Bull. Chem. Soc. Ethiop. 2021, 35(1), 33-42. DOI: https://dx.doi.org/10.4314/bcse.v35i1.3