Spectroscopic, luminescence and in vitro biological studies of solid ketoprofen of heavier trivalent lanthanides and yttrium(III)

Solid-state compounds of the general formulae [ML3] (M = Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y; L = ketoprofen) were synthesized and characterized using infrared, diffuse reflectance and luminescence spectroscopies. IR data suggested that the carboxylate group in ketoprofen is coordinated to the metals as a bidentate ligand. The triplet state energy level was determined using the Gd3 + complex, which exhibited a ketoprofen blue luminescence when excited in the UV region. The compound containing Tb3 + ion was sensitized by the ligand and emitted in the green region of the visible spectrum. On the other hand, for the analogous species containing the dysprosium ion, a competition for luminescence between the Dy3 + and the ligand levels was observed. Finally, Tm3 + complex exhibits only ligand luminescence. These optical behaviors are discussed based on rare earth energy diagrams. In addition, the compounds were evaluated for their anti-inflammatory activities. All the compounds showed a higher production of H2O2 and IL-10 than the ketoprofen, suggesting that the compounds exhibited an immunomodulatory effect and this opens up new perspectives for immunotherapeutic approaches.

Graphical abstractThis work deals with the synthesis and characterization of complexes of ketoprofen with heavier lanthanides and yttrium. The anti-inflammatory activities of the compounds were evaluated and the luminescent properties of terbium, dysprosium and thulium complexes were studied.Figure optionsDownload full-size imageDownload as PowerPoint slide