Cyclic and square wave voltammetry of chitooligosaccharides modified by osmium(VI) tetramethylethylenediamine.

Bioelectrochemistry

Institute of Biophysics, The Czech Academy of Sciences, Královopolská 135, 61265 Brno, Czech Republic. Electronic address:

Published: June 2020

Compounds containing vicinal diol (glycol) groups, including saccharides, could be modified with sixvalent osmium complexes with nitrogenous ligands, particularly with N,N,N',N'-tetramethylethylenediamine (Os(VI)tem). The modification products are electrochemically active. Here we show that aminosaccharides can also be modified by Os(VI)tem. We studied chitosan oligosaccharides in their acetylated and deacetylated form in 0.2 M Na-phosphate, pH 6.9. Deacetylated chitosan oligosaccharides with free amino groups modified by Os(VI)tem yielded two peaks (peak I' at -0.15 V and peak II' at about -0.38 V) despite the fact that these oligomers contain only one glycol group on the non-reducing end of the molecule. The electrochemical behavior of Os(VI)tem modified deacetylated chitosan oligomers differs from Os(VI)tem modified simple saccharides, containing only glycol groups, predominantly in peak I'. Our results suggest that free amino groups are involved in Os(VI)tem modification of chitosan oligomers.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bioelechem.2020.107494DOI Listing

Publication Analysis

Top Keywords

glycol groups
8
osvitem modification
8
modified osvitem
8
chitosan oligosaccharides
8
deacetylated chitosan
8
free amino
8
amino groups
8
osvitem modified
8
chitosan oligomers
8
modified
6

Similar Publications

In this study, polyethylene glycol (PEG) and dextran (Dex) were chemically modified to obtain amino-functionalized PEG (PEG-(NH)) and oxidized dextran (ODex). They were subsequently reacted via -NH and -CHO groups to synthesize a macromolecular Schiff base particle. The structures, morphologies, and thermal properties of the macromolecular Schiff base particle were characterized using Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and thermogravimetry analysis (TGA).

View Article and Find Full Text PDF

Chlorhexidine-loaded microneedles for treatment of oral diseases.

Int J Pharm

December 2024

Department of Pharmaceutical Engineering, Azrieli College of Engineering Jerusalem, Jerusalem 9103501, Israel. Electronic address:

Chlorhexidine (CHX) is a gold standard therapeutic agent against clinical oral pathogens. However, its oral use is limited due to unpleasant taste, alteration in taste buds, staining of teeth and mucous membranes. Therefore, CHX-loaded PLGA microneedles (MNs) were fabricated for local and controlled release in the oral cavity, using a casting mold method.

View Article and Find Full Text PDF

Maintaining hexagonal structures through interfacial positioning of crosslinkers for nanofiltration.

J Colloid Interface Sci

December 2024

Institute for Frontier Materials, Deakin University, Geelong VIC 3216, Australia. Electronic address:

Hypothesis: Optimizing interfacial positioning of crosslinkers within a reactive self-assembled hexagonal lyotropic liquid crystals (HLLC) system could assist in retaining the hexagonal structure during polymerization and thereby improving water filtration performances of the as-synthesized nanofiltration membranes.

Experiments: The positioning of the hydrophilic crosslinker, poly (ethylene glycol) diacrylate (PEGDA), within the reactive HLLC system was systematically investigated using H and C solid nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. The structural variation and water filtration performances of these HLLC systems with/without crosslinkers after polymerization were further studied using grazing incidence SAXS (GISAXS) and crossflow filtration tests, respectively.

View Article and Find Full Text PDF

Objective: To analyze the efficacy and tolerability of aceclofenac in the treatment of patients with acute non-specific musculoskeletal pain in the lower back (ANBP) compared with other NSAIDs (dexketoprofen, nimesulide and lornoxicam), as well as to assess the impact of NSAIDs therapy on the relative risk of recurrence and chronicity of this pathology.

Material And Methods: The study involved 80 patients (47 women and 33 men), average age 52.6 [47.

View Article and Find Full Text PDF

Significance: Artificial tears remain the cornerstone for managing dry eye disease. The current study's real-world efficacy test of carboxymethylcellulose (CMC), polyethylene glycol (PEG) 400, or sodium hyaluronate (SH)-based lubricants highlights their similar effects on noninvasive tear film parameters over the short term. However, patients reported better relief with SH-based lubricants.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!