Chemistry of singlet oxygen. XI. Cis-trans isomerization of carotenoids by single oxygen and a probable quenching mechanism

Foote, Christopher S.; Chang, Yew C.; Denny, Robert W.

doi:10.1021/ja00720a037

Cited by 104 publications

(38 citation statements)

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“…In this study, the major change in the ability of carotenoid pigments to protect against chlorophyll photobleaching occurred in the pigments containing between five and seven 655 double bonds and indicated that the carotenoid with seven double bonds was effective in this process (81). 1 Another possibility for carotenoid quenching of o 2 has been raised by Foote et al (82). Their suggestion involved reversible electron transfer from carotene to lo 2 whic~could also be dependent on the polyene chain length.…”

Section: Mechanisms Of Carotenoid Protection Against 1 Omentioning

confidence: 62%

Carotenoid protection against oxidation

Krinsky¹

1979

Pure and Applied Chemistry

379

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Based on experimental observations made in photosynthetic organisms which lacked colored carotenoid pigments, a hypothesis was developed that these pigments could serve as protective agents against photosensitized oxidations. Over the last 20 years, many workers have confirmed this hypothesis and have extended the observations to non-photosynthetic bacteria, plants and animals. It has also been possible to demoostrate carotenoid protection in in vitro systems. This article reviews the major mechanisms whereby carotenoid pigments protect cells against harmful photosensitized oxidations. The mechanisms include:

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Section: Mechanisms Of Carotenoid Protection Against 1 Omentioning

confidence: 62%

Carotenoid protection against oxidation

Krinsky¹

1979

Pure and Applied Chemistry

379

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“…Due to their triplet energy levels lying close to that of 1 O 2 (1274 nm, 7849 cm −1 or 93.9 kJ/mole vs . 1380 nm, 7250 cm −1 or 86.7 kJ/mol for β-carotene, respectively [2,85]), they belong to the most efficient physical quenchers of 1 O 2 , both in vitro and in vivo [4,86,87]. The process of 1 O 2 quenching has been shown to be very efficient, especially for Crts having 11 conjugated double bonds (≈10 10 M −1 ·s −1 ) [77], though their protective behavior was demonstrated to be strongly medium-dependent [88,89].…”

Section: Carotenoids: Ros Interactionsmentioning

confidence: 99%

Potential Role of Carotenoids as Antioxidants in Human Health and Disease

2014

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Carotenoids constitute a ubiquitous group of isoprenoid pigments. They are very efficient physical quenchers of singlet oxygen and scavengers of other reactive oxygen species. Carotenoids can also act as chemical quenchers undergoing irreversible oxygenation. The molecular mechanisms underlying these reactions are still not fully understood, especially in the context of the anti- and pro-oxidant activity of carotenoids, which, although not synthesized by humans and animals, are also present in their blood and tissues, contributing to a number of biochemical processes. The antioxidant potential of carotenoids is of particular significance to human health, due to the fact that losing antioxidant-reactive oxygen species balance results in “oxidative stress”, a critical factor of the pathogenic processes of various chronic disorders. Data coming from epidemiological studies and clinical trials strongly support the observation that adequate carotenoid supplementation may significantly reduce the risk of several disorders mediated by reactive oxygen species. Here, we would like to highlight the beneficial (protective) effects of dietary carotenoid intake in exemplary widespread modern civilization diseases, i.e., cancer, cardiovascular or photosensitivity disorders, in the context of carotenoids’ unique antioxidative properties.

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“…In solution, ␤-carotene (Car) (1 in Scheme 1) very efficiently quenches chlorophyll a fluorescence at rates near to the diffusion limit and is able to protect chlorophylls from photobleaching (19,20). With its triplet energy lying below that of 1 O 2 , Car and other carotenoids are excellent physical quenchers of singlet oxygen ( 1 ⌬ g ) (13,16,21,22).…”

Section: Introductionmentioning

confidence: 99%

Photodynamics of the Bacteriochlorophyll-Carotenoid System. 1. Bacteriochlorophyll-photosensitized Oxygenation of β-Carotene in Acetone¶

Fiedor¹,

Fiedor²,

Winkler³

et al. 2007

Photochemistry and Photobiology

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Carotenoids are well-known physical quenchers of chlorophyll excited states and reactive oxygen species both in vivo and in vitro. They may also be involved in chemical quenching undergoing, e.g. isomerizations or oxidations. We have found that ␤-carotene (Car) in aerobic acetone is rapidly oxygenated under strong illumination with red light ( exc Ն 630 nm) in the presence of bacteriopheophytin a. At the same time the photosensitizer undergoes only slight (Ͻ10%) photodegradation. By preparative high-performance liquid chromatography as many as seven major products of oxygen attachment to Car have been isolated. Their molecular masses show that Car sequentially accumulates up to six oxygen atoms while its C 40 -skeleton remains intact.

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Chemistry of singlet oxygen. XI. Cis-trans isomerization of carotenoids by single oxygen and a probable quenching mechanism

Cited by 104 publications

References 1 publication

Carotenoid protection against oxidation

Carotenoid protection against oxidation

Potential Role of Carotenoids as Antioxidants in Human Health and Disease

Photodynamics of the Bacteriochlorophyll-Carotenoid System. 1. Bacteriochlorophyll-photosensitized Oxygenation of β-Carotene in Acetone¶

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