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Three new copper(II) complexes, [Cu(1,10‐Phen)(L)] (1), [Cu(2,2′‐Bpy)(L)] (2) and [Cu(3,4‐Lut)(L)] (3), where H2L=2‐[(2,4‐dihydroxyphenyl)methylidene]‐N‐(prop‐2‐en‐1‐yl)hydrazine‐1‐carbothioamide, 1,10‐Phen=1,10‐phenanthroline, 2,2′‐Bpy=2,2′‐bipyridine, 3,4‐Lut=3,4‐lutidine, have been synthesized and characterized by elemental analysis, FTIR spectroscopy and single crystal X‐ray crystallography (1, 2). All compounds are mononuclear. The introduction of a monodentate N‐heteroaromatic base (3,4‐dimethylpyridine) has led to a significant increase of antimicrobial activity against Gram‐negative Escherichia coli and antifungal activity against Candida albicans compared to the pro‐ligand and the precursor complex [Cu(L)H2O]. The introduction of bidentate N‐heteroaromatic bases did not lead to such increase of antimicrobial and antifungal activities. Moreover, complex 3 surpasses the inhibitory activity of tetracycline toward Enterobacter cloacae and the inhibitory activity of fluconazole toward Candida parapsilosis and Cryptococcus neoformans. The study of antioxidant activity against cation radicals ABTS⋅+ showed that complexes 1–3 are more active than Trolox, but only introduction of the monodentate N‐heteroaromatic base (3,4‐dimethylpyridine) led to the increase of antioxidant properties compared to the precursor complex. [ABSTRACT FROM AUTHOR]

The aim of this study was to synthesize silver nanoparticles (AgNPs) using cellulose derivatives and to evaluate their antimicrobial potential. As effective reducing and stabilizing agents for AgNPs, cellulose derivatives, such as hydroxypropyl cellulose (HPC), methylcellulose (MC), ethylcellulose (EC), and cellulose acetate (CA), were used. Their ability to reduce silver ions as well as the size of the resulting AgNPs were compared. The formation and stability of the reduced AgNPs in the solution were monitored using UV-Vis analysis. The size, morphology, and charge of the AgNPs were evaluated. We found that, when using cellulosic derivatives, AgNPs with sizes ranging from 17 to 89 nm and different stabilities were obtained. The parameters, such as size and ζ potential indicate the stability of AgNPs, with AgNPs-CA and AgNPs-HPC being considered more stable than AgNPs-EC and AgNPs-MC since they show higher ζ potential values. In addition, the AgNPs showed antimicrobial activity against all reference strains and clinical isolates. MIC values between 0.0312 and 0.125 mM had a bactericidal effect on both Gram-positive and Gram-negative bacteria. The fungicidal effect was obtained at a MIC value of 0.125 mM. These results may provide rational support in the design of medical gauze products, including gauze pads, rolls, and sponges. [ABSTRACT FROM AUTHOR]

New zinc (II), copper (II), nickel (II) and cobalt (III) complexes, [Zn (HL)2]I2(1), [Cu (HL)Cl2] (2), [Cu (HL)Br2] (3), [Cu (HL)(H2O)2](ClO4)2(4), [Ni (HL)2]I2·H2O (5), [Co(L)2]Cl (6), [Co(L)2]NO3(7), [Co(L)2]I·[Co(L)2](I3) (8) were obtained with 2‐formylpyridine 4‐allyl‐S‐methylisothiosemicarbazone (HL). The isothiosemicarbazone ligand was characterized by NMR (1H and 13C), IR spectroscopy and X‐ray diffraction. All the complexes were characterized by elemental analysis, IR, UV–Vis, ESI‐MS spectroscopy, molar conductivity, magnetic susceptibility measurements. X‐ray diffraction analysis on the monocrystal and powder elucidated the structure of the complexes 1, 5, 7 and 8. The ligand and the complexes were tested for their antioxidant and antimicrobial activity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Candida albicans. Also, the antiproliferative properties of these compounds on human leukemia HL‐60, human cervical epithelial HeLa, human epithelial pancreatic adenocarcinoma BxPC‐3, human muscle rhabdomyosarcoma spindle, large multinucleated RD cells and normal MDCK cells have been investigated. The nickel complex 5 and cobalt complexes 6, 7 showed promising antiproliferative activity and low toxicity. [ABSTRACT FROM AUTHOR]