Cyclic endoperoxides of beta-carotene, potential pro-oxidants, as products of chemical quenching of singlet oxygen.

Biochim Biophys Acta

Department of Plant Physiology and Biochemistry, Faculty of Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Cracow, Poland.

Published: August 2005

Photoprotection by carotenoids is generally considered to be based on the photophysical quenching of triplets and singlet oxygen. There is also accumulating evidence of an alternative, chemical quenching of triplets and singlet oxygen by carotenoids. We report the identification of relatively stable cyclic mono- and diendoperoxides as first products of such an alternative reaction. Nevertheless, these species remain reactive and in the dark cause autooxidation of beta-carotene in our model system. Their formation could explain the intriguing pro-oxidant and cytotoxic activity of carotenoids.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbabio.2005.05.008DOI Listing

Publication Analysis

Top Keywords

singlet oxygen
12
chemical quenching
8
quenching triplets
8
triplets singlet
8
cyclic endoperoxides
4
endoperoxides beta-carotene
4
beta-carotene potential
4
potential pro-oxidants
4
pro-oxidants products
4
products chemical
4

Similar Publications

Introduction: The successful diagnosis and treatment of early-stage breast cancer enhances the quality of life of patients. As a promising alternative to recently developed magnetic resonance imaging-guided radiotherapy, we proposed fluorescence molecular imaging-guided photodynamic therapy (FMI-guided PDT), which requires no expensive equipment. In the FMI simulations, ICG-C11 which has emission peaks at near-infrared wavelengths was used as the FMI agent.

View Article and Find Full Text PDF

NIR photo-responsive injectable chitosan/hyaluronic acid hydrogels with controlled NO release for the treatment of MRSA infections.

Int J Biol Macromol

January 2025

Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning 530000, China. Electronic address:

Due to resistance to common antibiotics, methicillin-resistant Staphylococcus aureus (MRSA) infections pose a significant threat to human health. In this study, we developed an injectable, adhesive, and biocompatible hydrogel with multiple functions. Specifically, carboxymethyl chitosan (CMCS) crosslinked with hyaluronic acid (HA) forms the primary framework of the hydrogel.

View Article and Find Full Text PDF

Exploring the degradation of ofloxacin in sewer overflows by Fe(Ⅵ)/PMS, Fe(Ⅵ)/PDS, and Fe(Ⅵ)/SPC: Overlooked synergistic effect of oxidation and in-situ coagulation.

J Hazard Mater

January 2025

State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.

Sewer overflows are a potential source of emerging contaminants to urban waters, posing a threat to ecosystems and human health. Herein, the performance and mechanism of ferrate(Ⅵ) (Fe(Ⅵ))/peroxymonosulfate (PMS), Fe(Ⅵ)/peroxydisulfate (PDS), and Fe(Ⅵ)/percarbonate (SPC) for the degradation of ofloxacin (OFL) in overflows were comparatively investigated. These systems achieved efficient degradation of OFL and the removal of conventional pollutants.

View Article and Find Full Text PDF

Environmentally-friendly rGO/Mn nanocomposites for efficient removal of tetracycline and its degradation pathway.

J Environ Manage

January 2025

Fujian Province Key Laboratory of Pollution Control and Resource Reuse, College of Environmental and Resource Science, Fujian Normal University, Fuzhou, 350007, Fujian Province, China. Electronic address:

Since the widespread use of antibiotics, the residues of antibiotics have frequently been detected in various water sources, making antibiotic pollution an urgent environmental issue. In this paper, one-step green synthetic reduced graphene/manganese nanoparticles (rGO/Mn NPs) composites have been utilized as a novel environmentally-friendly catalyst for tetracycline (TC) removal. The results demonstrated that rGO/Mn NPs exhibit excellent adsorption performance for TC, and can efficiently activate sodium persulfate (PDS) to oxidize and degrade TC.

View Article and Find Full Text PDF

Nanosheet-shaped WS/ICG nanocomposite for photodynamic/photothermal synergistic bacterial clearance and cutaneous regeneration on infectious wounds.

Biomater Adv

January 2025

Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, School of Basic Medical Sciences and Life Sciences, Hainan Medical University, Haikou 571199, China. Electronic address:

Bacterial infections present a significant threat to human health, a challenge that is intensified by the slow pace of novel antibiotic development and the swift emergence of bacterial resistance. The development of novel antibacterial agents is crucial. Indocyanine green (ICG), a widely used imaging dye, efficiently generates reactive oxygen species (ROS) and heat for treating bacterial infections but suffers from aggregation and instability, limiting its efficacy.

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!