Synthesis, characterization and biological applications of curcumin-lysine based schiff base and its metal complexes

The Schiff base derived from curcumin and lysine and its Co, Ni, Cu and Zn(II) complexes have been synthesized and characterized by FT-IR, UV-Vis, 1H NMR and elemental analysis. Conductivity measurement showed a non-electrolytic complex. Thermogravimetric (TG/DTG) analyses of Cu complex confirm the stability followed by thermal decomposition in different steps. The UV-Vis and magnetic susceptibility data of the complexes suggest tetrahedral geometry around the central metal ion except the Cu(II) complex which has a square planar geometry. The XRD and SEM studies revealed the nanocrystalline behavior for the complex. The antimicrobial activity of the Schiff base and its metal chelates were screened against bacteria, such as E. coli and P. aeruginosa. The antifungal activity was screened against C. albicans. The result shows that metal chelates have better antimicrobial activity than the Schiff base. The larvicidal activity of the Schiff base and its metal complexes have been studied and the result revealed that the Cu(II) complex shows more activity than the Schiff base.