Determination of Singlet Oxygen-Specific versus Radical-Mediated Lipid Peroxidation in Photosensitized Oxidation of Lipid Bilayers:  Effect of β-Carotene and α-Tocopherol†

Biochemistry ◽  
1997 ◽  
Vol 36 (42) ◽  
pp. 12911-12920 ◽  
Author(s):  
Steven P. Stratton ◽  
Daniel C. Liebler
2004 ◽  
Vol 37 (11) ◽  
pp. 1854-1863 ◽  
Author(s):  
Noriko Bando ◽  
Hiroki Hayashi ◽  
Saori Wakamatsu ◽  
Takahiro Inakuma ◽  
Mariko Miyoshi ◽  
...  

2014 ◽  
Vol 84 (Supplement 1) ◽  
pp. 25-29 ◽  
Author(s):  
Guangwen Tang

Humans need vitamin A and obtain essential vitamin A by conversion of plant foods rich in provitamin A and/or absorption of preformed vitamin A from foods of animal origin. The determination of the vitamin A value of plant foods rich in provitamin A is important but has challenges. The aim of this paper is to review the progress over last 80 years following the discovery on the conversion of β-carotene to vitamin A and the various techniques including stable isotope technologies that have been developed to determine vitamin A values of plant provitamin A (mainly β-carotene). These include applications from using radioactive β-carotene and vitamin A, depletion-repletion with vitamin A and β-carotene, and measuring postprandial chylomicron fractions after feeding a β-carotene rich diet, to using stable isotopes as tracers to follow the absorption and conversion of plant food provitamin A carotenoids (mainly β-carotene) in humans. These approaches have greatly promoted our understanding of the absorption and conversion of β-carotene to vitamin A. Stable isotope labeled plant foods are useful for determining the overall bioavailability of provitamin A carotenoids from specific foods. Locally obtained plant foods can provide vitamin A and prevent deficiency of vitamin A, a remaining worldwide concern.


2017 ◽  
Vol 61 (4) ◽  
pp. 53-58
Author(s):  
I. Strapáč ◽  
M. Kuruc ◽  
M. Baranová

AbstractExtracts of the fruiting bodies of the Oyster mushroom (Pleurotus ostreatus) grown on wood substrates (beech, oak, linden, walnut, poplar) and extracts of the fruiting bodies of the Oyster mushroom (Pleurotus pulmonarius) grown in nature on aspen wood were used to determine the total phenols, total flavonoids, lycopene and β-carotene. The content of individual antioxidants varies considerably depending, not only on the substrate, but also on the extracting agents. The highest content of total phenols and total flavonoids was found in methanol and water extracts of the fruiting bodies of the Oyster mushrooms grown on oak and linden substrates. The maximum content of lycopene and β-carotene was determined in acetone and n-hexane (ratio 4 : 6) extracts of the fruiting bodies of the Oyster mushroom grown on an oak block. The results obtained in this study demonstrated that the quantitative and also probably the qualitative composition of the antioxidants in the fruiting bodies of Oyster mushrooms depended considerably on the substrate composition.


2007 ◽  
Vol 2 ◽  
pp. 117739010700200 ◽  
Author(s):  
Tamara Zoltan ◽  
Franklin Vargas ◽  
Carla Izzo

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.


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