Curcumin (a major constituent of widely-used spice and colouring agent, turmeric) was found to be very effective in antagonising the S9-mediated mutagenicity of several food-derived heterocyclic amines. In order to understand the chemical basis of antimutagenic properties of curcumin against these mutagens, we have studied the structure–activity relationship between curcumin and its naturally-occurring derivatives, namely demethoxycurcumin and bisdemethoxycurcumin, and other structurally-related natural and synthetic analogues of curcumin, namely tetrahydrocurcumin, dibenzoylmethane, dibenzoylpropane, vanillin, ferulic acid, isoferulic acid and caffeic acid, using Ames Salmonella/reversion assay, against different classes of cooked food mutagens. We conclude that unsaturation in the side chain, a methoxy group on the benzene ring and a central β-diketone moiety in the curcumin molecule are the important structural requirements responsible for high antimutagenic potential of curcumin against cooked food heterocyclic amines.
