scholarly journals Singlet Oxygen Is the Major Reactive Oxygen Species Involved in Photooxidative Damage to Plants

2008 ◽  
Vol 148 (2) ◽  
pp. 960-968 ◽  
Author(s):  
Christian Triantaphylidès ◽  
Markus Krischke ◽  
Frank Alfons Hoeberichts ◽  
Brigitte Ksas ◽  
Gabriele Gresser ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Singlet Oxygen ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Photooxidative Damage

UV-Vis Spectrophotometrical and Analytical Methodology for the Determination of Singlet Oxygen in New Antibacterials Drugs

2007 ◽  
Vol 2 ◽  
pp. 117739010700200 ◽  
Author(s):  
Tamara Zoltan ◽  
Franklin Vargas ◽  
Carla Izzo
Keyword(s):  
Reactive Oxygen Species ◽  
Singlet Oxygen ◽  
Nalidixic Acid ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Inexpensive Method ◽  
Analytical Methodology ◽  
First Time

We have determined and quantified spectrophotometrically the capacity of producing reactive oxygen species (ROS) as 1O2 during the photolysis with UV-A light of 5 new synthesized naphthyl ester derivates of well-known quinolone antibacterials (nalidixic acid (1), cinoxacin (2), norfloxacin (3), ciprofloxacin (4) and enoxacin (5)). The ability of the naphthyl ester derivatives (6-10) to generate singlet oxygen were detecting and for the first time quantified by the histidine assay, a sensitive, fast and inexpensive method. The following tendency of generation of singlet oxygen was observed: compounds 7 >10 > 6 > 8 > 9 >> parent drugs 1-5.

scholarly journals Reactivity of Several Reactive Oxygen Species (ROS) with the Sesquiterpene Cacalol

2008 ◽  
Vol 3 (4) ◽  
pp. 1934578X0800300
Author(s):  
Manuel Jiménez-Estrada ◽  
Ricardo Reyes-Chilpa ◽  
Arturo Navarro-Ocaña ◽  
Daniel Arrieta-Báez
Keyword(s):  
Reactive Oxygen Species ◽  
Hydroxyl Radical ◽  
Singlet Oxygen ◽  
Furan Ring ◽  
Reactive Oxygen ◽  
Antioxidant Effect ◽  
Oxygen Species ◽  
Site Reaction ◽  
Hexanedioic Acid ◽  
Antioxidant Effects

To analyze the antioxidant effects of cacalol we determined its reactivity with different reactive oxygen species (ROS). Cacalol gave rise to cacalone by a specific site reaction with a hydroxyl radical. Singlet oxygen reacted only with the double bond of the furan ring, causing its rupture. On the other hand, ozone reacted with all double bonds in cacalol affording 2-methyl-hexanedioic acid as an end product. No reaction was observed with either superoxide or hydrogen peroxide. The potential antioxidant effect of cacalol as a scavenger of hydroxyl radical and singlet oxygen could be related to its function in the plant roots.

scholarly journals Reactivity of graphene oxide with reactive oxygen species (hydroxyl radical, singlet oxygen, and superoxide anion)

2019 ◽  
Vol 6 (12) ◽  
pp. 3734-3744 ◽  
Author(s):  
Hsin-Se Hsieh ◽  
Richard G. Zepp
Keyword(s):  
Reactive Oxygen Species ◽  
Graphene Oxide ◽  
Hydroxyl Radical ◽  
Singlet Oxygen ◽  
Superoxide Anion ◽  
Reactive Oxygen ◽  
Toxic Effects ◽  
Oxygen Species ◽  
Ecological Risks

Increases in the production and applications of graphene oxide (GO), coupled with reports of its toxic effects, are raising concerns about its health and ecological risks.

Exploring environment-dependent effects of Pd nanostructures on reactive oxygen species (ROS) using electron spin resonance (ESR) technique: implications for biomedical applications

2015 ◽  
Vol 17 (38) ◽  
pp. 24937-24943 ◽  
Author(s):  
Tao Wen ◽  
Weiwei He ◽  
Yu Chong ◽  
Yi Liu ◽  
Jun-Jie Yin ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Electron Spin Resonance ◽  
Singlet Oxygen ◽  
Electron Spin ◽  
Biomedical Applications ◽  
Reactive Oxygen ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Spin Resonance ◽  
Ph Dependent

Pd nanostructures can promote the decomposition of H2O2 in a pH-dependent manner and scavenge superoxide and singlet oxygen.

scholarly journals Endophytic Bacterium-Triggered Reactive Oxygen Species Directly Increase Oxygenous Sesquiterpenoid Content and Diversity in Atractylodes lancea

2015 ◽  
Vol 82 (5) ◽  
pp. 1577-1585 ◽  
Author(s):  
Jia-Yu Zhou ◽  
Jie Yuan ◽  
Xia Li ◽  
Yi-Fan Ning ◽  
Chuan-Chao Dai
Keyword(s):  
Reactive Oxygen Species ◽  
Singlet Oxygen ◽  
Oxidative Burst ◽  
Reactive Oxygen ◽  
Endophytic Bacterium ◽  
Enzymatic Oxidation ◽  
Oxygen Species ◽  
Oxidation Reactions ◽  
In Planta ◽  
Content Type

ABSTRACTOxygenous terpenoids are active components of many medicinal plants. However, current studies that have focused on enzymatic oxidation reactions cannot comprehensively clarify the mechanisms of oxygenous terpenoid synthesis and diversity. This study shows that an endophytic bacterium can trigger the generation of reactive oxygen species (ROS) that directly increase oxygenous sesquiterpenoid content and diversity inAtractylodes lancea.A. lanceais a famous but endangered Chinese medicinal plant that contains abundant oxygenous sesquiterpenoids. Geo-authenticA. lanceaproduces a wider range and a greater abundance of oxygenous sesquiterpenoids than the cultivated herb. Our previous studies have shown the mechanisms behind endophytic promotion of the production of sesquiterpenoid hydrocarbon scaffolds; however, how endophytes promote the formation of oxygenous sesquiterpenoids and their diversity is unclear. After colonization byPseudomonas fluorescensALEB7B, oxidative burst and oxygenous sesquiterpenoid accumulation inA. lanceaoccur synchronously. Treatment with exogenous hydrogen peroxide (H2O2) or singlet oxygen induces oxidative burst and promotes oxygenous sesquiterpenoid accumulationin planta. Conversely, pretreatment of plantlets with the ROS scavenger ascorbic acid significantly inhibits the oxidative burst and oxygenous sesquiterpenoid accumulation induced byP. fluorescensALEB7B. Furtherin vitrooxidation experiments show that several oxygenous sesquiterpenoids can be obtained from direct oxidation caused by H2O2or singlet oxygen. In summary, this study demonstrates that endophytic bacterium-triggered ROS can directly oxidize oxygen-free sesquiterpenoids and increase the oxygenous sesquiterpenoid content and diversity inA. lancea, providing a novel explanation of the mechanisms of oxygenous terpenoid synthesisin plantaand an essential complementarity to enzymatic oxidation reactions.

scholarly journals Proteins Needed to Activate a Transcriptional Response to the Reactive Oxygen Species Singlet Oxygen

mBio ◽  
2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Tae-Wook Nam ◽  
Eva C. Ziegelhoffer ◽  
Rachelle A. S. Lemke ◽  
Timothy J. Donohue
Keyword(s):  
Reactive Oxygen Species ◽  
Stress Response ◽  
Singlet Oxygen ◽  
Rhodobacter Sphaeroides ◽  
Transcriptional Response ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Wild Type ◽  
Content Type ◽  
Σ Factor

ABSTRACT Singlet oxygen (1O2) is a reactive oxygen species generated by energy transfer from one or more excited donors to molecular oxygen. Many biomolecules are prone to oxidation by 1O2, and cells have evolved systems to protect themselves from damage caused by this compound. One way that the photosynthetic bacterium Rhodobacter sphaeroides protects itself from 1O2 is by inducing a transcriptional response controlled by ChrR, an anti-σ factor which releases an alternative sigma factor, σE, in the presence of 1O2. Here we report that induction of σE-dependent gene transcription is decreased in the presence of 1O2 when two conserved genes in the σE regulon are deleted, including one encoding a cyclopropane fatty acid synthase homologue (RSP2144) or one encoding a protein of unknown function (RSP1091). Thus, we conclude that RSP2144 and RSP1091 are each necessary to increase σE activity in the presence of 1O2. In addition, we found that unlike in wild-type cells, where ChrR is rapidly degraded when 1O2 is generated, turnover of this anti-σ factor is slowed when cells lacking RSP2144, RSP1091, or both of these proteins are exposed to 1O2. Further, we demonstrate that the organic hydroperoxide tert-butyl hydroperoxide promotes ChrR turnover in both wild-type cells and mutants lacking RSP2144 or RSP1091, suggesting differences in the ways different types of oxidants increase σE activity. IMPORTANCE Oxygen serves many crucial functions on Earth; it is produced during photosynthesis and needed for other pathways. While oxygen is relatively inert, it can be converted to reactive oxygen species (ROS) that destroy biomolecules, cause disease, or kill cells. When energy is transferred to oxygen, the ROS singlet oxygen is generated. To understand how singlet oxygen impacts cells, we study the stress response to this ROS in Rhodobacter sphaeroides, a bacterium that, like plants, generates this compound as a consequence of photosynthesis. This paper identifies proteins that activate a stress response to singlet oxygen and shows that they act in a specific response to this ROS. The identified proteins are found in many free-living, symbiotic, or pathogenic bacteria that can encounter singlet oxygen in nature. Thus, our findings provide new information about a stress response to a ROS of broad biological, agricultural, and biomedical importance.

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