Synthesis, Characterization and Anticandida Activity of Schiff Bases Derived from 7-Amino-4-Methylquinolin-2(1H)-One and Substituted Salisaldehydes with their Cu(II) Complexes

Abstract

Schiff bases (SB¹-SB³) were synthesized from equimolar condensation reaction of 7-amino-4-methyl-quinolin-2(1H)-one with substituted salisaldehydes. The Schiff base ligands were then reacted with Cu(II) acetate in a 1:2 metal-to-ligand ratio to form Cu(II) Complexes (A¹ - A³). The synthesized Schiff bases and their complexes were characterized based on the Solubility test, Molar Conductance, Melting /decomposition temperature, Magnetic susceptibility, Flourier Transform Infrared Spectral Analysis (FT-IR), Proton Nuclear Magnetic Resonance (H¹-NMR), ESI-Mass spectrometry, and powder XRD analysis. The result of the solubility test shows that the Schiff bases and their complexes have poor solubility in water and other solvents except for hot DMSO. The Molar conductance values ranged from 22.5 - 25.5 ohm^-1cm²mol^-1 showing that the complexes were non-electrolytes. The magnetic susceptibility revealed that all the Cu(II)complexes were paramagnetic and ranged from 1.70 to 1.84 BM. The spectral analysis shows that the Schiff bases coordinate to the copper ion through its imine nitrogen and phenolic oxygen. The Schiff bases and their complexes were screened for their inhibitory activity against four Candida albican isolates and Candida albican ACCT 2876, the result indicated moderate activity when compared with a standard drug (Terbinafine).