Synthesis of novel pyrimidine-based Schiff base complexes: Targeting Amyloid-β aggregation in Alzheimer's disease

A novel Schiff base with imine/amine donors, 5-((3,3-diphenylalilidene)amino)pyrimidine-4-amine (L), and its new Platinum(II) and Ruthenium(II) complexes (I and II) were synthesized and characterized using FT-IR, ¹H NMR, ¹³C NMR, mass spectrometry and elemental analyses. The ability of these complexes to inhibit amyloid beta (Aβ_1-42) aggregation was evaluated using the human neuroblastoma cell line (SH-SY5Y). The complexes effectively inhibited Aβ_1-42 aggregation at a 1:1 M ratio. Both complexes increased cell viability up to 80 % at concentrations of 10 μM. At this concentration, the cell viability value found by Aβ_1-42 aggregation is around 65 %. Aggregation kinetics were fluorometrically monitored using Thioflavin T. These findings were further supported by scanning electron microscopy and transmission electron microscopy. In addition, the interaction of the complexes with Aβ_1-16 was investigated using MALDI-TOF/MS and ¹H NMR spectroscopy. All findings showed that Aβ_1-42 in both complexes is active in the inhibition of amyloid aggregation.