Dose-, time-and lipophilicity-dependent silver(I)-N- heterocyclic carbene complexes: Synthesis, characterization and interaction with plasmid and Aedes albopictus DNA

作者：Asekunowo Patrick O; Haque Rosenani A; Razali Mohd R; Avicor Silas W; Wajidi Mustafa F F

来源：Applied Organometallic Chemistry, 2017, 31(7): e3655.

DOI：10.1002/aoc.3655

• Aedes albopictus DNA
• Ag-NHC complex
• DNA binding
• N-heterocyclic carbene
• nuclease activity
• X-ray diffraction

Four new Ag(I)-N-heterocyclic carbene (NHC) complexes (5-8) bearing symmetrically substituted NHC ligands have been synthesized starting from the corresponding benzimidazolium bromide salts which are accessible in a single step from N-substituted benzimidazoles (N-alkyl and N-aryl) and subsequently reacted with the basic metal source Ag2O in acetonitrile-methanol. These compounds were characterized using elemental analyses, H-1 NMR, C-13 NMR, Fourier transform infrared and UV-visible spectroscopic techniques, and molar conductivity. Single-crystal structural studies for complex 5 show that the Ag(I) centre has a perfectly linear C-Ag-C coordination, with quasi-parallel pairs of aromatic benzimidazole planes. All the complexes interact with Aedes albopictus DNA via intercalation mode by a large hypochromicity of 22 and 27% and smaller hypochromicity of 16 and 19%. Furthermore, all complexes exhibit efficient DNA cleavage activity via a non-oxidative mechanistic pathway. The DNase activities of the test compounds revealed a time-and concentration-dependent activity pattern. The Ag(I)-NHC complexes showed considerably higher DNA cleavage activity compared to their respective benzimidazolium salts at a lower concentration. The DNA cleavage of these complexes changed from a moderate effect to a good one, corresponding to the increasing lipophilicity order of the complexes as 5 < 6 < 7 < 8 (1.02, 1.05, 1.78 and 2.06 for 5-8, respectively). This order is further corroborated with the DNA binding study, but with the exception of complex 5, which shows a better binding ability for DNA (K-b = 3.367 x 10(6)) than complexes 6-8 (6.982 x 10(5), 8.376 x 10(5) and 1.223 x 10(6), respectively).

• 出版日期2017-7