Abstract
Benzimidazole Schiff base ligand (E)-2-bromo-4-chloro-6-((4-(6-fluoro-1H-benzo[d]imidazol-2-yl)phenylimino)methyl)phenol (1) and corresponding Cu(II) (2), Pd(II) (3) and Zn(II) (4) complexes were synthesized successfully. The structural elucidations were carried out by FTIR and NMR (H-1 NMR and C-13 NMR) spectroscopic techniques while molecular formulae and stoichiometry were confirmed by ESPMALDI mass spectral analyses. We presented the biological worth of the synthesized compounds. UV-vis absorption spectroscopy provided strong evidence of interaction with salmon sperm DNA (SS-DNA), allowing us to calculate the intrinsic binding constant (K-b), equal to 2.33x10(5), 3.38x10(5), 1.1x10(5), 6.9x10(4) for 1, 2, 3 and 4 respectively. The preferential affinity order was further verified by thermal melting (T-m) of DNA. In the presence of compounds 1, 2, 3 and 4, T, value of DNA (68.5 degrees C for pure DNA) was increased to 75.0, 75.4, 71.0 and 73.2 degrees C respectively. Results were highly coherent with absorption titrations, proving complex 2 an efficient DNA intercalator. Molecular docking was carried out to evaluate the interaction of the synthesized compounds with double-stranded DNA both in vitro and in silico. The investigations showed a correlation between binding constants and activity, indicating the development of highly active compounds. The synthetic probes were screened for preliminary antineoplastic activity against Agrobacterium tumefaciens induced tumors in potato discs. Every compound displayed tumor inhibition activity, especially 2 inhibited up to 60% tumors with IC50 value equal to 0.3 mg/ml. Nontoxic nature of synthesized compounds was confirmed by exerting no considerable life-threatening effect on Artemia cells when exposed even to their higher concentration.