Structure of a terbium(III)-quinizarine complex: the first crystallographic model for metalloanthracyclines.
The crystal structure of a complex of terbium(III) with quinizarine 2-sulfonate has been solved by single-crystal X-ray diffraction methods. The metal cation is coordinated by two adjacent phenolate and quinone oxygens of the anthraquinone moiety of a quinizarine sulfonate anion and by six water molecules. To our knowledge, this is the first structure of a metal complex of the 1,4-dihydroxy anthraquinone ligand. On the basis of strict similarities in the spectroscopic features of the terbium adducts with either doxorubicin or quinizarine 2-sulfonate, the present structure is proposed as a model for the metal complexes of anthracyclines.
Department of Chemistry, University of Florence, Via della Lastruccia 3, I-50019 Sesto Fiorentino, Florence, Italy.
Massimo
M
Di Vaira
Pierluigi
P
Orioli
Francesca
F
Piccioli
Bruno
B
Bruni
Luigi
L
Messori