Efficiencies of singlet oxygen production and rate constants for oxygen quenching in the S1state of dicyanonaphthalenes and related compounds

2008 ◽  
Vol 7 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Fujio Tanaka ◽  
Kazuyuki Tsumura ◽  
Tomoaki Furuta ◽  
Kenichi Iwamoto ◽  
Masami Okamoto
Keyword(s):  
Singlet Oxygen ◽  
Rate Constants ◽  
Oxygen Production ◽  
Oxygen Quenching ◽  
Related Compounds

Carotenoids, tocopherols and thiols as biological singlet molecular oxygen quenchers

1990 ◽  
Vol 18 (6) ◽  
pp. 1054-1056 ◽  
Author(s):  
PAOLO Di MASCIO ◽  
THOMAS P. A. DEVASAGAYAM ◽  
STEPHAN KAISER ◽  
HELMUT SIES
Keyword(s):  
Singlet Oxygen ◽  
Molecular Oxygen ◽  
Rate Constants ◽  
Protective Action ◽  
Biological Tissues ◽  
Oxygen Quenching ◽  
Quenching Rate ◽  
Singlet Molecular Oxygen ◽  
Singlet Oxygen Quenching ◽  
Β Carotene

Singlet molecular oxygen (1O2) has been shown to be generated in biological systems and is capable of damaging proteins, lipids and DNA. The ability of some biological antioxidants to quench 1O2 was studied by using singlet oxygen generated by the thermodissociation of the endoperoxide of 3,3′-(1,4-naphthylidene) dipropionate (NDPO2). The carotenoid lycopene was the most efficient 1O2 quencher (kq + kr = 31 × 109m-1s-1). Tocopherols and thiols were less effective. The singlet oxygen quenching ability decreased in the following order: lycopene, γ-carotene, astaxanthin, canthaxanthin, α-carotene, β-carotene, bixin, zeaxanthin, lutein, bilirubin, biliverdin, tocopherols and thiols. However, the compounds with low quenching rate constants occur at higher levels in biological tissues. Thus, carotenoids and tocopherols may contribute almost equally to the protection of tissues against the deleterious effects of 1O2. The quenching abilities of carotenoids and tocopherols were mainly due to physical quenching. In case of some thiols chemical quenching also plays a significant role. Carotenoids and tocopherols have been reported to exert a protective action against some types of cancer.

scholarly journals Effects of low temperature and cold-acclimation on photoinhibition and singlet oxygen production in four natural accessions of Arabidopsis

2019 ◽  
Author(s):  
Heta Mattila ◽  
Kumud B. Mishra ◽  
Iiris Kuusisto ◽  
Anamika Mishra ◽  
Kateřina Novotná ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Low Temperature ◽  
Singlet Oxygen ◽  
Cold Acclimation ◽  
Rate Constants ◽  
Thylakoid Membranes ◽  
Oxygen Species ◽  
Optimal Conditions ◽  
Oxygen Production ◽  
Quinone Acceptor

AbstractTo understand the effects of low temperature and cold-acclimation on reactive oxygen species and photoinhibition of photosystem II (PSII), light-induced inactivation of PSII was measured at 22 and 4 °C from four Arabidopsis thaliana accessions (Rschew, Tenela, Columbia-0 and Coimbra) grown under optimal conditions. Photoinhibition was also measured at 4 °C from plants cold-acclimated at 4 °C for two weeks. Measurements were done in the absence and presence of lincomycin that blocks PSII repair, and PSII activity was assayed with the ratio of variable to maximum chlorophyll a fluorescence (FV/FM) and with light-saturated rate of oxygen evolution using a quinone acceptor. Of the non-acclimated accessions, Rschew was the most tolerant to photoinhibition and Coimbra the least; the rate constants of photoinhibition of the most sensitive accession were 1.3-1.9 times as high as those of the tolerant ones. The damaging reaction of photoinhibition in non-acclimated plants was slower or equal at 4 °C than at 22 °C. The rate constants of photoinhibition of cold-acclimated plants, at 4 °C, were 0.55 to 1.25 times as high as those of non-acclimated plants; the protective effect of cold-acclimation on photoinhibition was consistent in Columbia-0 and Coimbra whereas Rschew and Tenela were either slightly more tolerant or susceptible, depending on the method used to assay photoinhibition. Production of singlet oxygen, measured from thylakoid membranes isolated from non-acclimated and cold-acclimated plants, did not decrease due to cold-acclimation, nor did singlet oxygen production correlate with the rate of photoinhibition or with flavonol contents of the leaves.

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