singlet oxygen


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sin·glet ox·y·gen

an excited or higher-energy form of oxygen characterized by the spin of a pair of electrons in opposite directions, whereas electron spin is unidirectional in normal molecular oxygen Because of its great reactivity, singlet oxygen is a probable intermediate in most photooxidation reactions. Although it exists for no more than 0.1 second, it may react with atmospheric pollutants to foster smog formation and may have harmful biologic effects.

singlet oxygen

A highly active form of oxygen produced during reactions of hydrogen peroxide with superoxide and hypochlorite ions. It is believed that this free radical is bactericidal.
See also: oxygen
References in periodicals archive ?
Xanthohumol showed the highest activity in total oxygen radical absorbance capacity as well as singlet oxygen absorbance capacity.
Buettner, "Molecular targets of photosensitization--some biological chemistry of singlet oxygen," in Photobiology Sciences on Line, K.
Singlet oxygen is one of the strongest reactive oxygen species (ROS) that damages biological lipids, proteins and DNA.
The resulting oxidant injury is not thought to be mediated by singlet oxygen (Chiarpotto et al.
An activated LS11 molecule results in the production of singlet oxygen molecules, which can kill target tissues with minimal side effects through vascular closure and apoptosis, or "programmed cell death.
Singlet oxygen is known to oxidize bacterial proteins or lipids, thereby causing the death of affected bacteria.
Their role is probably to filter out phototoxic blue light and to quench singlet oxygen.
In 2003, Brunswick Laboratories received a Small Business Innovation Research (SBIR) grant from the USDA to develop ORAC assays for singlet oxygen, hydroperoxide and superoxide anion.
Reduced glutathione, which is a substrate for glutathione peroxidase, neutralizes hydroxyl radicals and singlet oxygen.
It is known that oxygen reactive species (subperoxide, perhydroxide, hydrogen peroxide, hydoxyl, singlet oxygen, peroxyl) and also nitrogen reactive species play key roles in skin disorders, including cancer, psoriasis and photoaging.
Although [beta]-carotene is an excellent quencher of singlet oxygen photogenerated in plants and certain bacteria, we were intrigued how [beta]-carotene might function as an antioxidant in mammalian cells.