Design, synthesis, characterization and biological studies of copper(II) complexes with 2‐aminobenzimidazole derivatives as biomimetic agents

Abstract

Four novel copper(II) complexes of 2‐aminobenzimidazole derivatives (obtained from the Knoevenagel condensation of acetylacetone (obtained from acetylacetone and halogen‐substituted benzaldehydes) and 2‐aminobenzimidazole) were synthesized. They were characterized using elemental analysis, molar conductance measurements, and fast atom bombardment mass, Fourier transform infrared, NMR, UV–visible and electron paramagnetic resonance spectroscopies. On the basis of the spectral studies, a distorted square planar geometry was assigned for all the complexes. The antibacterial screening of the ligands and their complexes revealed that all the complexes had higher activities than the free ligands. Superoxide dismutase and antioxidant activities of the copper complexes were also studied. The shifts in ΔEp, E1/2, Ipc and Ipa values were explored for the interaction of the complexes with calf thymus DNA using the electrochemical technique.

Design and preparation of [4,4′-bipyridine]-1,1′-diium trinitromethanide (BPDTNM) as a novel nanosized ionic liquid catalyst: application to the synthesis of 1-(benzoimidazolylamino)methyl-2-naphthols

“…As illustrated in the FT-IR spectra (Figures 1a and 1b Figure 1c generally showing redshifts in catalyst 5. As portrayed in Figure 2, the 1 H-and 13 CNMR spectra (DMSO-d 6 ) of 5, verified the formation of the catalyst. In the 1 H NMR spectrum, the aromatic protons of the 4,4'-bipyridine rings, resonate as two multiplets in the aromatic region.…”

“…The existence of -NH pyridinium groups within the structure of the nanosized catalyst was confirmed by observation of corresponding broad singlet at 12.5 ppm ( Figure 2a). With respect to the 13 CNMR spectrum, the resonance peak at 160.9 ppm is ascribed to the trinitromethanide carbon, while aromatic carbon atoms appear at 125.8, 122.6, and 119.4 ppm (Figure 2b).…”

“…were obtained on a Bruker Avance 300 NMR and a Bruker Avance 400 NMR spectrometers, respectively, under proton coupled mode using deuterated DMSO as a solvent. 13 C NMR (101 MHz) spectra were acquired on a Bruker Avance 400 NMR spectrometer in the proton decoupled mode at 20 °C in deuterated DMSO as solvent, unless otherwise stated. Chemical shifts are given in δ (parts per million) and the coupling constants (J) in hertz.…”

“…Other interesting applications of benzimidazoles include their used as ionic liquids [7] and N-heterocyclic carbine precursors [8,9]. Guanidine-containing organic compounds such as 2aminobenzimidazole [10,11] present a wide spectrum of applications in the field of pharmaceutical and biological drug design, being the activity against multidrug resistant bacteria the most notable example (Scheme 1) [12][13][14][15]. More recently, chiral 2aminobenzimidazoles have been successfully used as bifunctional Brønsted base/hydrogen bonding organocatalysts [16][17][18][19][20].…”

Biomimetic complexes‐graphene composites for redox processes

“…Biomimicry, learning from biological living, processes, and ecosystems, as the highest efficiency alternative approach to sustainability is the biggest innovation of the 21 st century. This high‐tech assistive technology expanded a new outlook for the preparation of the synthetic materials or machines that inspired by biological and nature patterns . Biomimetic chemistry is a term that was defined for the first time in 1972 to introduced chemistry that is inspired by natural processes .…”