Table of Contents
Metal-Based Drugs
Volume 2007 (2007), Article ID 15925, 8 pages
Research Article

New Samarium(III), Gadolinium(III), and Dysprosium(III) Complexes of Coumarin-3-Carboxylic Acid as Antiproliferative Agents

1Department of Chemistry, Faculty of Pharmacy, Medical University, 2 Dunav Street, Sofia 1000, Bulgaria
2Department of Pharmacology and Toxicology, Faculty of Pharmacy, Medical University, 2 Dunav Street, Sofia 1000, Bulgaria
3Department of Inorganic Chemistry, University of Sofia, Sofia 1000, Bulgaria

Received 31 August 2006; Revised 16 November 2006; Accepted 27 December 2006

Academic Editor: Domenico Osella

Copyright © 2007 Irena Kostova et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


New complexes of samarium(III), gadolinium(III), and dysprosium(III) with coumarin-3-carboxylic acid (HCCA) were prepared by the reaction of the ligand with respective metal nitrates in ethanol. The structures of the final complexes were determined by means of physicochemical data, elemental analysis, IR and Raman spectra. The metal-ligand binding mode in the new Ln(III) complexes of coumarin-3-carboxylic acid was elucidated. The vibrational study gave evidence for bidentate coordination of CCA to Ln(III) ions through the carbonylic oxygen and the carboxylic oxygen atoms. The complexes were tested for antiproliferative activitiy on the chronic myeloid leukemia-derived K-562, overexpressing the BCR-ABL fusion protein. Cytotoxicity towards tumor cells was determined for a broad concentration range. The samarium salt exerted a very weak antiproliferative effect on these cells. This is in contrast to the lanthanide complexes, especially samarium complex, which exhibited potent antiproliferative activity. The present study confirms our previous observations that the lanthanide complexes of coumarins exhibit antiproliferative activity towards K-562 cell line.