%0 Journal Article
%T Synthesis and Antioxidant Activities of Novel 5-Chlorocurcumin, Complemented by Semiempirical Calculations
%A Ahmed A. Al-Amiery
%A Abdul Amir H. Kadhum
%A Hasan R. Obayes
%A Abu Bakar Mohamad
%J Bioinorganic Chemistry and Applications
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/354982
%X The novel curcumin derivative (1E,4Z,6E)-5-chloro-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,4,6-trien-3-one (5-chlorocurcumin) was prepared from natural curcumin. The newly synthesised compound was characterised by spectral studies (IR, 1H NMR, and 13C NMR). The free radical scavenging activity of 5-chlorocurcumin has been determined by measuring interaction with the stable free radical DPPH, and 5-chlorocurcumin has shown encouraging antioxidant activities. Theory calculations of the synthesised 5-chlorocurcumin were performed using molecular structures with optimised geometries. Molecular orbital calculations provided a detailed description of the orbitals, including spatial characteristics, nodal patterns, and the contributions of individual atoms. 1. Introduction Curcumin (1) [diferuloylmethane, 1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-hepta-diene-3,5-dione] is a well-known acyclic diarylheptanoid identified as the major constituent of turmeric powder extracted from the rhizome of the plant Curcuma longa [1, 2]. Curcumin (1) has potent antioxidant activity [3¨C5] and has received attention as a promising nutraceutical or as a component of designer foods for its cancer preventive ability. With a unique conjugated structure including two methoxylated phenols and an enol ¦Â-diketone, curcumin shows a typical radical-trapping ability as a chain-breaking antioxidant. The antioxidant mechanism of curcumin and curcumin-related phenols has attracted significant attention [6¨C8], but it is still not well understood. In addition, curcumin blocks growth factor signaling via inhibition of tyrosine kinase activity or depletion of ErbB-2 [9]. More recently, it has been shown that curcumin causes cleavage of h-catenin, resulting in apoptosis in a colon cancer¡ªderived cell line [10]. Antioxidant compounds play an important role as a health protecting factor. Scientific evidence suggests that antioxidants reduce the risk for chronic diseases including cancer and heart disease. Primary sources of naturally occurring antioxidants are whole grains, fruits, and vegetables. Plant sourced food antioxidants like vitamin C, vitamin E, carotenes, phenolic acids, phytate, and phytoestrogens have been recognized as having the potential to reduce disease risk. Most of the antioxidant compounds in a typical diet are derived from plant sources and belong to various classes of compounds with a wide variety of physical and chemical properties. Some compounds, such as gallates, have strong antioxidant activity, while others, such as the monophenols, are weak antioxidants [11]. For
%U http://www.hindawi.com/journals/bca/2013/354982/