Curcumin ligand based iridium(III) complexes as inhibition and visualization agent of beta-amyloid fibrillation

In this work, curcumin ligand based Ir(III) complexes are synthesized. Their applications in the inhibiting and monitoring the fibrillation of Beta-amyloid (A beta) peptides have been investigated. Ascribed to the outstanding photophysical properties of Ir(III) complex skeleton and the abundant functional groups of curcumin ligand, the newly developed Ir(III) complexes possess excellent recognition and inhibition ability towards A beta 42 peptide aggregation. Experimental results show that these complexes can effectively inhibit and monitor A beta 42 peptide aggregation in vitro. Ir-3-cur can inhibit seed-mediated A beta 42 peptide fibrillation completely with the concentration of 50 mu M. Moreover, Ir-3-cur is able to distinguish A beta 42 fibril from its monomer with 9.4-fold signal increase. These Ir(III) complexes have the potency superior to previously reported curcumin. Furthermore, the cytotoxicity of these Ir(III) complexes were also investigated, demonstrating a low toxicity and neuro-protective ability against the cytotoxicity caused by three forms of A beta 42 peptides.

Automated summary

In this work, a series of curcumin ligand based Ir(III) complexes were synthesized and investigated for their outstanding ability to inhibit and monitor the fibrillation of A beta 42 peptides. The experimental results showed that these complexes can effectively inhibit and monitor A beta 42 peptide aggregation in vitro, with some complexes even completely inhibiting fibrillation at a concentration of 50 mu M. Additionally, these complexes demonstrated low cytotoxicity and neuro-protective ability against the cytotoxicity caused by three forms of A beta 42 peptides, showing potential for therapeutic applications in Alzheimer's disease.