METAL-CHELATES OF CURCUMINOIDS

Curcuminoids, a group of structurally related 1,3-dicarbonyl compounds , are the most important physiologically active components present in the traditional herbaceous medicinal plant oriental turmeric (Curcuma longa Linn., Zingiberaceae family). Nickel(II), copper(II), zinc(II) a nd paliadium(II) chelates of synthetic analogues of these 1,7-diaryl-1 ,6-heptadiene-3,5-diones have been synthesized. UV, IR, H-1 and C-13 N MR and mass spectral data of the ML2 complexes clearly indicate that t he metal ion replaced the enol proton with the formation of a stable s ix-membered metal chelate ring involving the dicarbonyl function.