Quenching singlet-oxygen

Characterization and singlet oxygen quenching ability of spray-dried microcapsules of edible biopolymers containing antioxidant molecules. Journal of Agricultural and Food Chemistry, Vol. 58, No.l3, (June 2010), pp. 8004-8011, ISSN 0021-8561. 

Montenegro, M.A. Nazareno, M.A Durantini, E.N. Borsarelli, G.D. (2002). Singlet oxygen quenching ability of carotenoids in a reverse micelle membrane mimetic system. Photochemistry and Photobiology, Vol. 75, No. 4, (April 2002), pp.353-361, ISSN 0031-8655... 

Mercadante, A.Z. Alvarez, R.M.S. Borsarelli, G.D. (2009). Singlet oxygen quenching and radical scavenging capacities of structurally related flavonoids present in Zuccagnia punctata Gav. Free Radical Research, Vol.43, No.6, (January 2009), pp. 553-564, ISSN 1071-5762... 

The ability of carotenoids to act as antioxidants is closely related to their long-chain conjugated polyene structures (see Section 2.2 in Chapter 2). Two main types of antioxidant actions can be distinguished singlet oxygen quenching and reactions with radicals. The first mechanism occurs in vivo in plants and has been extensively studied in vitro. Reactions with radicals of different types have also been extensively studied in vitro under different conditions but their occurrence in vivo is still a matter of discussion. 

Di Mascio, R, Kaiser, S., and Sies, H., Lycopene as the most efficient biological carotenoid singlet oxygen quencher. Arch. Biochem. Biophys., 274, 532, 1989. Cantrell, A. et ah. Singlet oxygen quenching by dietary carotenoids in a model membrane environment. Arch. Biochem. Biophys., 412, 47, 2003. 

Cantrell, A. et al., Singlet oxygen quenching by dietary carotenoids in a model membrane environment, Arch. Biochem. Biophys., 412, 47, 2003. 

Kobayashi, M. and Sakamoto, Y., Singlet oxygen quenching ability of astaxanthin esters from the green alga Haematococcus pluvialis, Biotechnol. Lett., 21, 265, 1999. 

Baltschun, D., S. Beutner, K. Briviba et al. 1997. Singlet oxygen quenching abilities of carotenoids. Liebigs Ann. Recueil. 1887-1893. 

The observation that lutein in the retina is converted to (meso)-zeaxanthin appears to be physiologically plausible due to the presence of, in comparison to lutein, one additional conjugated double bond, it has a stronger singlet oxygen quenching capability (Cantrell et al. 2003). Furthermore, it has been reported that (meso)-zeaxanthin provides a somewhat better protection against the oxidation... 

Singlet Oxygen Quenching Rate Constants for Carotenoids in Benzene... 

Figure 14.4 shows that 3-CRYP (like all carotenoids in homogeneous solution and all except ZEA in liposomes) exhibits a linear plot with the quenching of 02 increasing as the concentration of the carotenoid increases. While ZEA shows a bell-shaped plot and zero singlet oxygen quenching at concentrations >70 d,M (see Figure 14.5). Such behavior of ZEA is symptomatic of its unique...

Stahl, W., Nicolai, S., Briviba, K., Hanusch, M., Broszeit,G., Peters, M., Martin, H.D., Sies, H., 1997. Biological activities of natural and synthetic carotenoids Induction of gap junctional communication and singlet oxygen quenching. Carcinogenesis. 18, 89-92. 

Fig. 34 Photosensitized singlet oxygen production 1/ r is the general (radiative and non-radiative) rate constant of the transition Si So fcsi is the rate constant of singlet-triplet conversion tt is the lifetime of the triplet, T1, electronic state of PS kj is the second-order rate constant of singlet oxygen quenching of the Ti state of PS tl and nr are the radiative lifetime and rate constant of all intramolecular nonradiative energy relaxation processes of O2 ( Ag)...

Scurlock R, Rougee M, Bensasson RV. 1990. Redox properties of phenols, their relationships to singlet oxygen quenching and to their inhibitory effects on benzo(a)-pyrene-induced neoplasia. Free Radic Res Commun 8 251-258. 

Lycopene, the predominant carotenoid in tomatoes (Solatium lycopersicum), exhibits the highest antioxidant activity and singlet oxygen quenching ability of all dietary... 

Awareness of lycopene as a potentially beneficial carotenoid in the nutritional and medical sciences is less than 10 years old. Therefore, comparatively few scientific data are available from animal and human studies. But in this short time, a number of features of lycopene have emerged that are unique among the common carotenoids, quite apart from its exceptionally high singlet oxygen quenching capacity in vitro. The most obvious distinction is that unlike the other hydrocarbon carotenoids, a- and P-carotene, lycopene has no provitamin A activity. 

Juan C, Stefflova K, Niedre K, et al. Protease-triggered photosensitizing beacon based on singlet oxygen quenching and activation. J Am Chem Soc 2004 126 11450-1. 

Zheng G, Chen J, Stefflova K, Jarvi M, Li H, Wilson BC. Photodynamic molecular beacon as an activatable photosensitizer based on protease-controlled singlet oxygen quenching and activation. Proc Natl Acad Sci USA 2007 104 8989-94. 

Pyrene can sensitize the photooxidation of 1,3-diphenylisobenzofuran (72) in DTAC micellar solutions 61>. The reaction involves sensitization of singlet oxygen by pyrene which diffuses into another micelle and reacts with (72). Indole and tryptophan, which also react with singlet oxygen, quench the above reaction in ethanol solutions. However, in micellar systems they enhance the rate of reaction. Because of the high local concentrations of the quencher, the pyrene excited state is quenched by indole and tryptophan which leads to the photooxidation of (72) by a Type I process. 

Metal chelation Oxygen scavenging and reducing agents Singlet oxygen quenching Cirtic, Malic, Succinic and Tartaric acids Ethylenediaminetetraacetic acid, Phosphates Ascorbic acid, Ascorbyl palmitate, Erythorbic acid. Sodium erythorbate. Sulfites Carotenoids (p-Carotene, Lycopene and Lutein)... 

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