New homochiral and heterochiral Mo(VI) complex from racemic ligand: Synthesis, X-ray structure, diastereomers separation and biological activities

A diastereomeric pair (homochiral and heterochiral) of Schiff base dioxo molybdenum complex was synthesized using chiral ligand (HL: R/S-1-((naphtalen-3-yl)methylenamino)propan-2-ol) in racemic form. Then, to separation of this diastereomeric pair, crystallization method was proposed which was successful with acetonitrile. H-1 NMR technique was used to confirm the results. The complexes thoroughly characterized using FT-IR, elemental analysis, H-1 NMR and C-13 NMR techniques, and MoO2L(LH2)(1) has been structurally characterized using single-crystal X-ray diffraction. The cytotoxic activity of the new compounds has been evaluated using MCF-7 (human breast adenocarcinoma) and HeLa (human cervix adenocarcinoma), in addition to normal human fibroblast cells using the MIT cytotoxicity assay. Compounds MoO2L(LH2)(1) and MoO2L(LH2)(2) revealed IC50 values 18 mu M and 37 mu M on MCF-7 and 58 mu M and 17 mu M on HeLa, respectively. MoO2L(LH2)(2) showed high selectivity (3-13 folds) for cancerous cells over normal cells, as the maximum cell mortality of 8.77%. Furthermore, The HSA- and DNA-binding of the Mo(VI) complexes were investigated by absorption, emission spectroscopy, viscosity measurements and molecular docking. Their binding constant are calculated as: HSA-binding of MoO2L(LH2)(1) is 6.7 x 10(4) M-1 and of MoO2L(LH2)(2) is 5.8 x 10(4) M-1, while their DNA-binding are 5.6 x 10(4) M-1 and 2.2 x 10(5) M-1, respectively. Their thermodynamic parameters were also determined at different temperatures. (C) 2019 Elsevier Ltd. All rights reserved.