Recent research raises the prospect that such activity should be taken into account in order to better tailor therapies.
Image credit: ScienceSource/Dennis Kunkel Microscopy.
New Research In
Physical Sciences
Featured Portals
Articles by Topic
Biological Sciences
Featured Portals
Articles by Topic
Edited by Barbara J. Finlayson-Pitts, University of California, Irvine, CA, and approved January 22, 2020 (received for review November 25, 2019)
Significance
Autoxidation leads to the slow persistent destruction of organic molecules causing oxidative stress and associated disease. The prevailing autoxidation mechanism of unsaturated lipids involves chain reactions initiated and propagated by H-atom abstraction, mediated by peroxy radicals and other reactive oxygen species. Here we report experimental evidence for an autoxidation mechanism initiated by OH, which is unanticipated and proceeds by OH addition followed by pathways involving Criegee intermediates (CIs). Although CIs are routinely encountered in atmospheric and synthetic organic chemistry, their role in autoxidation is unexpected. Our results suggest that in all likelihood these exotic species play a much more prominent and general role in the chemistry of cells, food, petrochemicals, and the environment beyond what is currently believed.
Abstract
Autoxidation is an autocatalytic free-radical chain reaction responsible for the oxidative destruction of organic molecules in biological cells, foods, plastics, petrochemicals, fuels, and the environment. In cellular membranes, lipid autoxidation (peroxidation) is linked with oxidative stress, age-related diseases, and cancers. The established mechanism of autoxidation proceeds via H-atom abstraction through a cyclic network of peroxy–hydroperoxide-mediated free-radical chain reactions. For a series of model unsaturated lipids, we present evidence for an autoxidation mechanism, initiated by hydroxyl radical (OH) addition to C=C bonds and propagated by chain reactions involving Criegee intermediates (CIs). This mechanism leads to unexpectedly rapid autoxidation even in the presence of water, implying that as reactive intermediates, CI could play a much more prominent role in chemistries beyond the atmosphere.
Footnotes
- ↵1To whom correspondence may be addressed. Email: KRWilson{at}lbl.gov.
Author contributions: M.Z. and K.R.W. designed research; M.Z. and N.H. performed research; M.Z. analyzed data; and M.Z., N.H., and K.R.W. wrote the paper.
The authors declare no competing interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at https://www.pnas.org/lookup/suppl/doi:10.1073/pnas.1920765117/-/DCSupplemental.
Published under the PNAS license.
Log in using your username and password
Purchase access
You may purchase access to this article. This will require you to create an account if you don't already have one.
Evidence that Criegee intermediates drive autoxidation in unsaturated lipids
Sign up for Article Alerts
Article Classifications
- Physical Sciences
- Chemistry
- Biological Sciences
- Environmental Sciences
Jump to section
You May Also be Interested in
A multitude of approaches are promising new ways to store, create, and deliver blood’s component parts to patients in need.
Image credit: Shutterstock/Shawn Goldberg.
Researchers report methane emissions from a natural gas well blowout in Ohio using measurements from a satellite-based instrument.
Image credit: National Institute for Occupational Safety and Health.
Field trials of engineered poplars suggest that suppression of isoprene, required for protection from climate stress but deleterious to air quality, does not significantly affect photosynthesis.
Image credit: Wikimedia/Iftikhor.
A study reports recent declines in mayfly emergence over major North American waterways.
Image credit: Phillip M. Stepanian.