Antioxidative Activities of Algal Keto Carotenoids Acting as Antioxidative Protectants in the Chloroplast. (26th February 2014)

• Record Type: Journal Article
• Authors: Dambeck, Michael; Sandmann, Gerhard
• Is Part Of: Photochemistry and photobiology. Volume 90:Number 4(2014:Jul./Aug.)
• Page Start: 814
• Page End: 819
• Publication Date: 2014-02-26
• Subjects: Photochemistry -- Periodicals; Light -- Physiological effect -- Periodicals; 541.35
• DOI: 10.1111/php.12249
• Languages: English
• ISSNs: 0031-8655

Abstract

<abstract abstract-type="main" id="php12249-abs-0001"> <title>Abstract</title> <p>Very diverse carotenoid structures exist in the photosynthesis apparatus of different algae. Among them, the keto derivatives are regarded the most antioxidative. Therefore, four different keto carotenoids, peridinin, fucoxanthin, siphonaxanthin and astaxanthin fatty acid monoesters, were isolated and purified from <italic>Amphidinium carterae</italic>, <italic> Phaeodactylum tricornutum, Caulerpa taxifolia</italic> and <italic>Haematococcus pluvialis</italic>, respectively. The carotenoids were assayed as inhibitors of photosensitizer initiated reactions or scavengers of radicals in the early events generating reactive oxygen species as starters for peroxidation and as protectants against the whole reaction chain finally leading to lipid peroxidation. These <italic>in vitro</italic> studies demonstrated the substantial antioxidative properties as indicated by the IC<sub>50</sub> values of all four keto carotenoids with superior protection by astaxanthin fatty acid monoesters which were as effective as free astaxanthin and of peridinin against radicals. As an example, the <italic>in vivo</italic> relevance of fucoxanthin for protection of photosynthesis from excess light and from peroxidative agents was evaluated with intact cells. Cultures of <italic>P. tricornutum</italic> with decreased fucoxanthin content generated by inhibitor treatment were exposed to strong light or cumene hydroperoxyde. In each case, oxidation of chlorophyll as marker for damaging of the photosynthesis apparatus was less severe when the fucoxanthin was at maximum level.</p> </abstract>