CuII Pyrazolyl-Benzimidazole Dinuclear Complexes with Remarkable Antioxidant Activity.

Three dinuclear coordination complexes generated from 1-n-butyl-2-((5-methyl-1H-pyrazole-3-yl)methyl)-1H-benzimidazole (L), have been synthesized and characterized spectroscopically and structurally by single crystal X-ray diffraction analysis. Reaction with iron(II) chloride and then copper(II) nitrate led to a co-crystal containing 78 % of [Cu(NO3 )(µ-Cl)(L')]2 (C1 ) and 22 % of [Cu(NO3 )(µ-NO3 )(L')]2 (C2 ), where L was oxidized to a new ligand L' . A mechanism is provided. Reaction with copper chloride led to the dinuclear complex [Cu(Cl)(µ-Cl)(L)]2 (C3 ). The presence of N-H⋅⋅⋅O and C-H⋅⋅⋅O intermolecular interactions in the crystal structure of C1 and C2 , and C-H⋅⋅⋅N and C-H⋅⋅⋅Cl hydrogen bonding in the crystal structure of C3 led to supramolecular structures that were confirmed by Hirshfeld surface analysis. The ligands and their complexes were tested for free radical scavenging activity and ferric reducing antioxidant power. The complex C1 /C2 shows remarkable antioxidant activities as compared to the ligand L and reference compounds.

Coordination complexes constructed from pyrazole-acetamide and pyrazole-quinoxaline: effect of hydrogen bonding on the self-assembly process and antibacterial activity.

Two mononuclear coordination complexes of N-(2-aminophenyl)-2-(5-methyl-1H-pyrazol-3-yl)acetamide (L1), namely [Cd(L1)2Cl2] (C1) and [Cu(L1)2(C2H5OH)2](NO3)2 (C2) and one mononuclear complex [Fe(L2)2(H2O)2](NO3)2·2H2O (C3), obtained after in situ oxidation of L1, have been synthesized and characterized spectroscopically. As revealed by single-crystal X-ray diffraction, each coordination sphere made of two heterocycles is completed either by two chloride anions (in C1), two ethanol molecules (in C2) or two water molecules (in C3). The crystal packing analysis of C1, C2 and C3, revealed 1D and 2D supramolecular architectures, respectively, via various hydrogen bonding interactions, which are discussed in detail. Furthermore, evaluation in vitro of the ligands and their metal complexes for their antibacterial activity against Escherichia coli (ATCC 4157), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923) and Streptococcus fasciens (ATCC 29212) strains of bacteria, revealed outstanding results compared to chloramphenicol, a well-known antibiotic, with a normalized minimum inhibitory concentration as low as 5 µg mL-1.

Intelligent food packaging film containing lignin and cellulose nanocrystals for shelf life extension of food.

The UV-protection films based on renewable materials extracted from natural sources are being one of the most interesting targets for the packaging industry. In this paper, the UV-protection films were produced based on modified lignin and cellulose nanocrystals, both were extracted from the Argania nutshell. The lignin was extracted via the alkylation process followed by chemical modification using epichlorohydrin. The chemical modification and the in-use temperature range of the films were investigated via FTIR and TGA, where the chemical modification of lignin improves the thermal property which is an essential parameter during the thermo-sealing of food packaging. On the other hand, the CNCs were extracted via acid hydrolysis treatment with the smallest size around 300 nm generating smooth texture of films. Finally, the produced films were shown a maximum absorption of the UV light in the range of 450-200 nm and great results in food packaging.

Synthesis of Surfactants Derived from 2-Mercaptobenzimidazole and Study of Their Acute Toxicity and Analgesic and Psychotropic Activities.

The aim of the present study is to synthesize cationic salts from a relatively toxic compound named 2-mercaptobenzimidazole and to evaluate some of their pharmacological properties. The acute toxicity of these salts is evaluated according to OECD 423 Guidelines at the doses of 300 and 2000 mg/kg; their peripheral analgesic effect is studied using the Koster test at the therapeutic dose of 200 mg/kg and their sedative action is evaluated using Traction, Chimney, Hole-board, and Rotarod tests at the doses of 200 and 400 mg/kg. All synthesized molecules show no acute toxicity according to OECD Code 423 guidelines at doses ranging from 300 to 2000 mg/kg and do not cause any obesity or anorexia. Also, the results of the Koster test show that the studied compounds have an average analgesic effect at the dose of 200 mg/kg compared to acetylsalicylic acid. In addition, the elaborated compounds have shown a moderate sedative effect at the dose of 400 mg/kg, in comparison to 2-mercaptobenzimidazole (400 mg/kg) and Bromazepam (20 mg/kg). These compounds have no cataleptic and hypnotic effects on the central nervous system at the doses of 200 and 400 mg/kg. These results argue in favor of a possible integration of the most active salts tested in the pharmaceutical industry owing to their analgesic and sedative effects.