An in vitro model of thalassemia was produced by entrapment of isolated hemoglobin chains in human erythrocytes, thus subjecting the loaded cells to oxidative stress. The presence of these unpaired chains induced physico-chemical modifications at the membrane level as studied by laurdan fluorescence. The polarity of the lipid bilayer was shown to decrease with a concomitant shift towards a gel phase in alpha-loaded erythrocytes. The determination of conjugated dienes before the hemolytic event was used as an oxidation index; the results obtained demonstrate that beta thalassemia is associated with oxidative stress. Furthermore, the presence of indolinic and quinolinic nitroxide radicals, a new class of antioxidants, in suspensions of alpha-loaded erythrocytes protected the erythrocytes from the hemolytic event. However, the protective effect exerted by the nitroxide radicals is not related to effects on membrane polarity and lipid peroxidation, even though a chemiluminescence study has demonstrated the superoxide scavenging activity of these nitroxide radicals.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/s0891-5849(96)00611-9 | DOI Listing |
Chemistry
January 2025
VIT University, Materials Chemistry Division, School of Advanced Sciences, VIT University, 632014, Vellore, INDIA.
Amidines are a vital class of bioactive compounds and often necessitate multiple components for their synthesis. Therefore, exploring efficient and sustainable methodologies for their synthesis is indispensable. Herein, we disclose an alternative and greener method for synthesizing an unexplored new class of amidines through the photochemical synergistic effect of copper/nitroxyl radical catalysis.
View Article and Find Full Text PDFChem Asian J
January 2025
University of Tasmania, School of Natural Sciences - Chemistry, AUSTRALIA.
Verdazyls are a fundamental class of stable organic radicals that have been traditionally overshadowed by the more synthetically accessible stable nitroxide radicals. With the advent of enhanced synthetic routes to verdazyls, particularly in recent years, these systems are now poised to realise their potential in a range of applications across emerging technologies that will be important to addressing challenges faced by modern society. This Concept discusses the enabling properties of a selection of verdazyl-based systems that feature promising applications in energy storage, molecular electronics and magnetic molecules.
View Article and Find Full Text PDFJ Org Chem
January 2025
Laboratory of Pharmaceutical Chemistry, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto 607-8412, Japan.
A one-pot, telescoped transformation of silyl ethers into cyanides that proceeds via silyl-ether oxidation mediated by nitroxyl-radical catalyst and [bis(trifluoroacetoxy)iodo]benzene followed by an imine formation-oxidation sequence using iodine and aqueous ammonia is reported. This transformation is effective for the site-selective transformation of benzylic and allylic silyl ethers in the presence of other silyl ethers. Using an -protected oxime and a catalytic amount of triflic acid instead of iodine/aqueous ammonia is also effective for cyanation.
View Article and Find Full Text PDFActa Biomater
January 2025
Institute of Smart Biomedical Materials, School of Materials Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, PR China. Electronic address:
The U.S. Food and Drug Administration (FDA) has issued a boxed warning and mandated additional safety measures for all gadolinium-based contrast agents (GBCAs) used in clinical magnetic resonance imaging (MRI) due to their prolonged retention in the body and associated adverse health effects.
View Article and Find Full Text PDFAntioxidants (Basel)
November 2024
Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
Reactive oxygen species (ROS) are double-edged swords in biological systems-they are essential for normal cellular functions but can cause damage when accumulated due to oxidative stress. Manganese superoxide dismutase (MnSOD), located in the mitochondrial matrix, is a key enzyme that neutralizes superoxide radicals (O), maintaining cellular redox balance and integrity. This review examines the development and therapeutic potential of MnSOD mimetics-synthetic compounds designed to replicate MnSOD's antioxidant activity.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!