RESEARCH PAPER On the use of X-ray absorption spectroscopy to elucidate the structure of lutetium adenosine mono- and triphosphate complexes S. Mostapha & C. Berthon & F. Fontaine-Vive & M. Gaysinski & L. Guérin & D. Guillaumont & L. Massi & I. Monfardini & P. L. Solari & O. P. Thomas & M. C. Charbonnel & C. Den Auwer Received: 28 March 2013 / Revised: 2 May 2013 / Accepted: 7 May 2013 # Springer-Verlag Berlin Heidelberg 2013 Abstract Although the physiological impact of the actinide elements as nuclear toxicants has been widely investigated for half a century, a description of their interactions with biological molecules remains limited. It is however of pri- mary importance to better assess the determinants of acti- nide speciation in cells and more generally in living organisms to unravel the molecular processes underlying actinide transport and deposition in tissues. The biological pathways of this family of elements in case of accidental contamination or chronic natural exposure (in the case of uranium rich soils for instance) are therefore a crucial issue of public health and of societal impact. Because of the high chemical affinity of those actinide elements for phosphate groups and the ubiquity of such chemical functions in bio- chemistry, phosphate derivatives are considered as probable targets of these cations. Among them, nucleotides and in particular adenosine mono- (AMP) and triphosphate (ATP) nucleotides occur in more chemical reactions than any other compounds on the earth’ s surface, except water, and are therefore critical target molecules. In the present study, we are interested in trans-plutonium actinide elements, in par- ticular americium and curium that are more rarely consid- ered in environmental and bioaccumulation studies than early actinides like uranium, neptunium and plutonium. A first step in this strategy is to work with chemical analogues like lanthanides that are not radioactive and therefore allow extended physical chemical characterization to be conducted that are difficult to perform with radioactive materials. We describe herein the interaction of lutetium(III) with adenosine AMP and ATP. With AMP and ATP, insoluble amorphous compounds have been obtained with molar ratios of 1:2 and 1:1, respectively. With an excess of ATP, with 1:2 molar ratio, a soluble complex has been obtained. A combination of spec- troscopic techniques (IR, NMR, ESI-MS, EXAFS) together with quantum chemical calculations has been implemented in order to assess the lutetium coordination arrangement for the two nucleotides. In all the complexes described in the article, the lutetium cation is coordinated by the phosphate groups of the nucleotide plus additional putative water molecules with various tridimensional arrangements. With AMP 1:2 and ATP 1:1 solid-state compounds, polynuclear complexes are assumed to be obtained. In contrast, with ATP 1:2 soluble compound, the Lu coordination sphere is saturated by two ATP ligands, and this favors the formation of a mononuclear complex. In order to further interpret the EXAFS data obtained at the Lu L III edge, model structures have been calculated for the 1:1 and 1:2 ATP complexes. They are discussed and compared to the EXAFS best fit metrical parameters. Keywords Nuclear toxicology . Nucleotides . Actinides . Lutetium . EXAFS Published in the special issue Analytical Science in France with guest editors Christian Rolando and Philippe Garrigues. Electronic supplementary material The online version of this article (doi:10.1007/s00216-013-7053-4) contains supplementary material, which is available to authorized users. S. Mostapha : C. Berthon : L. Guérin : D. Guillaumont : M. C. Charbonnel CEA Marcoule, DEN Radiochemistry and Processes Department, Laboratory of Interaction Ligand Actinide, 30207 Bagnols sur Cèze Cedex, France F. Fontaine-Vive : M. Gaysinski : L. Massi : I. Monfardini : O. P. Thomas : C. Den Auwer (*) Université Nice Sophia Antipolis, Nice Chemistry Institute UMR CNRS 7272, 06108 Nice, France e-mail: christophe.denauwer@unice.fr P. L. Solari Synchrotron SOLEIL, L ’Orme des Merisiers, Saint-Aubin, BP 48, F-91192 Gif-sur-Yvette Cedex, France Anal Bioanal Chem DOI 10.1007/s00216-013-7053-4