%0 Journal Article
%T Synthesis, Characterization, M£¿ssbauer Parameters, and Antitumor Activity of Fe(III) Curcumin Complex
%A Mutasim Ibrahim Khalil
%A Aisha Mohamed Al-Zahem
%A Maha Hamad Al-Qunaibit
%J Bioinorganic Chemistry and Applications
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/982423
%X Curcumin-Fe(III) complex was prepared from Fe(NO3)3¡¤9H2O precursor and curcumin by refluxing a slightly basic methanolic solution of their mixture with the objective of investigating its cytotoxicity. The enol form of curcumin ligand was established by FTIR, UV/Vis, 1H NMR, and 13C NMR spectroscopy. The as-prepared product was characterized by elemental analysis, FTIR, UV, and M£¿ssbauer spectroscopic techniques. An octahedral high-spin Fe(III) complex was obtained, ¦Ä, 0.37£¿mms£¿1; Q.S., 0.79£¿mms£¿1; no magnetic relaxation was observed at liquid N2 temperature, neither reduction of Fe(III). The tested cytotoxicity of the as-prepared complex on four cancer cell lines indicated inhibition of the curcumin activity upon complexing with iron. 1. Introduction The ¦Â diketone curcumin and curcuminoids (1,7-diaryl-1,6-heptadiene-3,5-diones) which are a group of naturally occurring 1,3-diketones have received considerable attention in the last few decades. This is due to the fact that they possess antitumor [1¨C3] and antioxidant effects [4] and have a good potential for metal ions complexation. It has been reported that metal complexation alters the various physiological properties especially the cytotoxic and antitumor activities of many naturally occurring compounds [5]. It is demonstrated that the coordination of metal ions, for example, Cu(II), Mn(II), Au(III), and so forth, with bioactive ligands can actually improve the pharmaceutical activity of drugs [6, 7]. The M£¿ssbauer metal isotopes, for example, Fe, Au, Ru, Ir, and so forth, form stable complexes with the curcumin ligand [8, 9]. Tonnesen and Greenhill [8] have reported the reduction of Fe(III) to Fe(II) in the presence of curcumin. However, there is no published M£¿ssbauer data on such complexes that could shed light on iron moiety and the correlation between the magnetic, symmetry, and oxidation states of metal ions in such chelates and their biological activity. In this paper we report the M£¿ssbauer data of Fe(curc)3 complex, compare it to the well-known Fe(acac)3 data, and identify and correlate oxidation state of the central iron metal ion, magnetic relaxation, and structural symmetry of the as-prepared complex to its antitumor cytotoxicity on four cancer cell lines. 2. Experimental 2.1. Chemicals and Materials All solvents (Sigma-Aldrich) were reagent grades and were used without further purifications. Curcumin (Sigma-Aldrich and Acros Organics) was extensively analyzed and the Sigma sample form was established. Fe(NO3)3¡¤9H2O (BDH) laboratory reagent was used. 2.2. Analytical Instruments FTIR
%U http://www.hindawi.com/journals/bca/2013/982423/