Anticandidal activity of cinnamaldehyde,its ligand and Ni(II) complex: Effect of increase in ring and side chain

To increase efficacy of cinnamaldehyde as an antimycotic agent, N, N′- Bis (trans-cinnamadehyde) ethylenediimine [C₂₀H₂₀N₂] and Ni(II) complex of the type [Ni(C₄₀H₄₀N₄)Cl₂] have been synthesized. The ligand [P] and Ni(II) complex have been characterized on the basis of elemental analysis, FTIR, ESI- MS, IR, ¹H NMR, UV–Vis spectroscopic techniques, conductivity and magnetic measurements. MIC of cinnamaldehyde against clinical isolate of Candida albicans and Candida tropicalis was 400 μg/ml and 500 μg/ml, respectively. Synthesized ligand has markedly reduced MIC; 200 μg/ml and 300 μg/ml whereas Ni(II) complex of ligand displayed MIC of 90 μg/ml and 120 μg/ml. Growth and sensitivity of the organisms were effected by ligand & complex at significantly reduced concentration. Plasma membrane ATPase activity and ergosterol content have been investigated as site of action. Result obtained indicates ergosterol biosynthesis pathway as site of action of cinnamaldehyde, synthesized ligand and its Ni(II) complex.