Search

Pectin is widely used in food and pharmaceutical industries. However, due to its polysaccharide nature it lacks antimicrobial activity. In the current work, new pectin derivatives with interesting optical and antimicrobial properties were prepared via supramolecular chemistry utilizing Fe- or Cu-terpyridine (Tpy-Fe and Tpy-Cu) motifs. To proof derivatization of pectin, ultraviolet-visible spectroscopy (UV-Vis) and Fourier Transform infrared (FTIR) were used. In addition, the prepared pectin derivatives retained the known emulsification activity of the non-modified sugar beet pectin as seen from the particle size analysis of oil-in-water emulsions. The prepared derivatives showed antibacterial activity toward selected Gram-positive and Gram-negative bacteria. In addition, cytotoxicity test showed that the Tpy-Fe-pectin derivative was non-toxic to cells of human hepatocarcinoma, breast adenocarcinoma MCF7, and colorectal carcinoma cells at concentrations up to 100 μg/ml, while Tpy-Cu-pectin had moderate toxicity toward the aforementioned cells at the same concentration levels. The prepared derivatives could have potential applications in emulsions with antibacterial activity., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Bionanocomposites were developed by casting/evaporation of wheat gluten (WG), cellulose nanocrystals (CNC), and TiO2 nanoparticles. The effect of addition of different percentages of CNC, and TiO2 on tensile strength (TS), Young's modulus and water sensitivity was studied. A significant improvement in the studied properties is observed when 7.5% CNC and 0.6% TiO2 is added to WG. WG/CNC 7.5%/0.6% TiO2 blend suspension was chosen to coat commercial packaging unbleached kraft paper sheets via 1, 2 and 3 coating layers. A significant enhancement of 56% and 53% in breaking length and burst index, respectively, was achieved for 3 layers coated paper. The antimicrobial activity of the coated papers, against Saccharomyces cervisiae, Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus, was investigated and expressed in terms of reduction % of surviving number (CFU) of the tested organisms. More than 98.5% reduction in CFU was observed against the organisms compared to TiO2-free coated paper., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Preparation of a new water-soluble, cellulose derivative via a supramolecular route is presented. In a one-step procedure, carboxymethyl cellulose (CMC) was reacted with the Cu(BF4)2 complex of 4'-chloro[2,2':6',2″]terpyridine to generate the desired CMC-Cu(II)-terpyridine derivative. This polymeric salt was characterized by elemental analysis, ultraviolet-visible spectroscopy (UV-visible), Fourier transform infrared (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), rheological properties measurements, thermogravimetric analysis (TGA), dynamic mechanical thermal analysis (DMTA), and tensile strength properties testing. In addition, antimicrobial properties were demonstrated against Gram-positive bacteria (Staphylococcus aureus and Streptococcus thermophilus), Gram-negative bacteria (Escherichia coli), and yeast (Saccharomyces cervisiae). The minimum inhibitory concentration of the prepared metallo-terpyridine CMC derivative against the studied microorganisms ranged from 6 to 8 mg/L to achieve ≥90% of microbial growth inhibition., (Copyright © 2014 Elsevier Ltd. All rights reserved.)