Synthesis, characterization, and anticancer potential of pyrene-appended Schiff base tin(iv) complexes: experimental and computational insights

In this study, we report the synthesis and comprehensive characterization of two novel pyrene-appended Schiff base organotin(IV) compounds, trimethylstannyl (E)-4-((pyren-1-ylmethylene)amino)benzoate (1) and triphenylstannyl (E)-4-((pyren-1-ylmethylene)amino)benzoate (2). They were synthesized through the condensation of trimethylstannyl 4-aminobenzoate or triphenylstannyl 4-aminobenzoate with 1-pyrenealdehyde in toluene. The characterization included elemental analysis, infrared spectroscopy, H-1, C-13, and Sn-119 NMR, and ESI-MS. The crystal structure of compound 1 was elucidated through single crystal X-ray diffraction analysis. The interaction of compounds 1 and 2 with calf thymus DNA (CT DNA) was investigated using absorption and fluorescence spectroscopic techniques. The calculated binding constants (K-b) unveiled a notably stronger binding propensity of compound 2 compared to 1. Furthermore, the in vitro cytotoxicity assays of these compounds were performed against human lung (A549) cancer cell lines, which revealed concentration-dependent cytotoxic effects, with 2 exhibiting a higher cytotoxicity than 1. Moreover, the scratch assay demonstrated the ability of both compounds to inhibit cancer cell migration, with 2 displaying stronger inhibitory effects. Furthermore, gene expression studies showed that both compounds downregulated the expression of MMP-2 and TGF-beta genes, indicating their potential in modulating critical signaling pathways in cancer cells. Molecular docking simulations provided insights into the binding interactions of these compounds with MMP-2 and TGF-beta, further supporting their potential as inhibitors of cancer-related proteins. Overall, our findings highlight the promising anticancer properties of these novel pyrene-appended Schiff base compounds, with 2 showing particular potency. This research provides an insight into the development of potential chemotherapeutic agents targeting cancer cell proliferation, migration, and signalling pathways.