Optically Active Oligomer Units in Aggregates of a Highly Unsaturated, Optically Inactive Carotenoid Phospholipid

Foss, Bjarne A.; Sliwka, Hans‐Richard; Partali, Vassilia; Köpsel, Christian; Mayer, Bernd; Martin, H.; Zsila, Ferenc; Bikádi, Zsolt; Simonyi, Miklós

doi:10.1002/chem.200401191

Cited by 23 publications

(12 citation statements)

References 59 publications

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“…Similarly, melittin, a natural membrane opener, did not assist the sensitizers in reaching the polyene chain. [58] Thus, aggregation of 2-4, 8, and 9 could prevent unwanted premature reactions in addition to the previously observed photostability. [30] Aggregate stability was further confirmed when 4 was heated with aqueous and methanolic HCl solutions (2 %) at 65 8C.…”

Section: Wwwchemeurjorgmentioning

confidence: 96%

Electron‐ and Energy‐Transfer Properties of Hydrophilic Carotenoids

Sliwka

Melø

Foss

et al. 2007

Chemistry A European J

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The antioxidant activities-expressed as the electron-donating properties-of five hydrophilic carotenoids (carotenoid surfactants) and three related hydrophobic carotenoids were investigated by flash photolysis. The electron-transfer rates of the carotenoids to the triplet state of the sensitizer 2-nitronaphthalene and the energy transfer rates of triplet 2-nitronaphthalene to the carotenoids were determined. The results demonstrate that the electron-donating effects of the hydrophilic and hydrophobic carotenoids were comparable when evaluated in acetonitrile. In the presence of water, however, electron transfer (i.e., antioxidant efficiency) was enhanced by a factor of four for the hydrophilic carotenoids. The increased hydrophilicity of carotenoids, therefore, could expand their antioxidant properties, thus facilitating their use as aqueous-phase radical scavengers. At the same time, it was shown that supramolecular assembly ("aggregation") of the amphiphilic carotenoids prevented electron transfer, thus deactivating the antioxidant function. Modulation of the biophysical properties of carotenoids through synthetic modification is capable of increasing the biological and medical utility of this natural class of predominantly hydrophobic antioxidant compound.

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Section: Wwwchemeurjorgmentioning

confidence: 96%

Electron‐ and Energy‐Transfer Properties of Hydrophilic Carotenoids

Sliwka

Melø

Foss

et al. 2007

Chemistry A European J

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“…Sliwka et al also synthetized and studied thoroughly remarkable phospholipid derivatized carotenoids like 4 [14,15,16], and also investigated the physicochemical properties of natural hydrophilic carotenoids such as bixin and crocin [17,18,19]. Recently, they have synthetized aldoxime and ketoxime hydrochlorides from oxo carotenoids, which showed moderate water dispersibility [20].…”

Section: Hydrophilic Salts Of Carotenoid Estersmentioning

confidence: 99%

Hydrophilic Carotenoids: Recent Progress

et al. 2012

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Carotenoids are substantially hydrophobic antioxidants. Hydrophobicity is this context is rather a disadvantage, because their utilization in medicine as antioxidants or in food chemistry as colorants would require some water dispersibility for their effective uptake or use in many other ways. In the past 15 years several attempts were made to synthetize partially hydrophilic carotenoids. This review compiles the recently synthetized hydrophilic carotenoid derivatives.

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“…[4] Our own calculation of neutral carotenoids had previously pointed to important variations. [30] Cationic triphenylmethanes have only recently been studied by computational methods; the results were not convergent with the experimental data. [31] Consequently, molecular modeling of charged polyenes such as CarO 2 + should be the subject of comprehensive forthcoming investigations.…”

Section: Leuco Dye Properties Of Caromentioning

confidence: 93%