Novel Schiff base-Pt(ii) complexes: inhibition of Aβ aggregation via histidine interaction

In this study, three Schiff base ligands (L1-L3) and their novel platinum(ii) complexes (I-III) were synthesized and characterized using FT-IR, NMR, and elemental analysis. The crystal structure of complex I was determined by X-ray crystallography, while the lipophilicity of the complexes was evaluated by UV-Vis spectroscopy. The ability of the compounds to inhibit A beta aggregation was assessed using the SH-SY5Y human neuroblastoma cell line. Due to its high cytotoxicity, comparable to that of cisplatin, complex II was excluded from further biological investigations. The kinetics of A beta aggregation inhibition were examined fluorometrically using Thioflavin-T, and the binding interactions of the complexes with the A beta 1-42 sequence were elucidated through studies of their interactions with l-histidine using 1H-NMR and LC/QTOF/MS analyses. The results demonstrate that complexes I and III significantly suppress A beta fibril formation, with IC50 values of 50 mu M and 25 mu M, respectively. The enhanced biological activity is attributed to the strong electron-donating properties of the ligand substituents. Overall, these findings reveal that the synthesized complexes effectively inhibit A beta amyloid aggregation and promote cell viability.