Geometrical isomerization of carotenoids in dichloromethane

Jeevarajan, A. S.; Wei, C. C.; Kispert, Lowell D.

doi:10.1039/p29940000861

Cited by 32 publications

(33 citation statements)

References 22 publications

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“…However, this picture is contrary to other reports, which have identified two all-trans b-carotene molecules via extraction and purification of the carotenoids from D1-D2-Cyt b 559 preparations (Fujiwara et al 1987;Yruela et al 1998). Previous studies have shown, however, that the manner in which the sample is handled can lead to isomerization of the b-carotene isolated from the PS II RC (Jeevarajan et al 1994;Bialek-Bylka et al 1995). Therefore, a definite conclusion on the b-carotene configuration may not be made from these extraction studies.…”

Section: Introductioncontrasting

confidence: 73%

Resonance Raman spectroscopy of carotenoids in Photosystem II core complexes

et al. 2005

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Resonance Raman (RR) spectroscopy has been used to examine the configuration of the carotenoids bound to Synechocystis PCC 6803 Photosystem II (PS II) core complexes. The excitation wavelengths used (514.5, 488.0, 476.5 and 457.9 nm) span the absorption bands of all of the approximately 12-17 neutral carotenoids in the PS II core complex. The RR spectra of the two carotenoids associated with the D1-D2 polypeptides (Car507 and Car489) of the reaction center are extracted via light versus dark difference experiments measured at 20 K. The RR results are consistent with all-trans configurations for both Car507 and Car489 and indicate that majority of the other carotenoids in the PS II core complex must also be in the all-trans configuration. The configuration of beta-carotene is relevant to its proposed function as a molecular wire in the secondary electron-transfer reactions of PS II.

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Section: Introductioncontrasting

confidence: 73%

Resonance Raman spectroscopy of carotenoids in Photosystem II core complexes

et al. 2005

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“…Since color conversion was not observed in acetone, MeOH and MeCN, traces of HCl in CH 2 Cl 2 or CDCl 3initially present or formed and increased during spectra re- cording [5] -are likely to initiate the reaction. Incomplete conversion gave green solutions resulting from mixing yellow CarO 3 and blue Car*.…”

Section: Resultsmentioning

confidence: 99%

“…Yellow CarO 3 reacted analogous to polymethine carbinols, allylic and benzylic alcohols: the tert-OH groups in these derivatives are removed by silica gel, traces of HCl (in chlorinated solvents), hydrolysis, Lewis acids such as FeCl 3 or light. [5,11,12,[21][22][23][24][25][26][27] Irradiation of CarO 3 , however, led to bleaching. FeCl 3 removed the hydroxy group in CarO 3 exclusively as Lewis acid and occurred not as electron acceptor, since variation in spectra and reactions were not noticed.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of a Highly Unsaturated, Stable Hydroxy Peroxide: A Yellow [lrarr2] Blue Color‐Changing Carotenoid Oxidation Product with Leuco Dye Properties

Rebmann

Øpstad

et al. 2010

Eur J Org Chem

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“…Ursache dafür ist der höhere Fruchtsäuregehalt der Tomaten. Aus Modelluntersuchungen ist bekannt, dass Säure die Carotinoidisomerisierung begünstigt (Jeevarajan et al 1994). Getrocknet wird pflanzliches Material in der Regel bei Temperaturen unter 80°C, so dass Isomerisierung bzw.…”

Section: Bedeutung Für Die Lycopinbioverfügbarkeitunclassified

Aspekte der Herstellung haltbarer, lycopinreicher Gemüse- und Obstprodukte

Mayer-Miebach

Behsnilian

2009

J. Verbr. Lebensm.

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Zusammenfassung Lycopin, ein Carotinoid, dem heute gesundheitsfördernde Eigenschaften zugeschrieben werden, ist aus frischen, nicht verarbeiteten Tomaten und anderen lycopinreichen Gemüse-und Obstarten für den menschlichen Organismus nur begrenzt bioverfügbar. Aus haltbaren Tomatenprodukten wird Lycopin dagegen verstärkt aufgenommen. Insbesondere thermische Verarbeitungsmethoden können einerseits die Lycopinbioverfügbarkeit erhöhen, andererseits bedingen sie gleichzeitig den Abbau des Lycopins. Ziel der vorliegenden Arbeit ist es daher, den aktuellen Kenntnisstand zum Einfluss häufig angewendeter verfahrenstechnischer Grundoperationen auf Lycopinstabilität und -bioverfügbarkeit zusammenzustellen und insbesondere im Hinblick auf die ernährungsphysiologische Bedeutung zu bewerten.Abstract Lycopene, actually assumed to be a health promoting carotenoid, is only poorly absorbed by humans from fresh and unprocessed tomatoes and other lycopene rich fruit and vegetables. In contrast, absorption is higher from processed foods such as tomato paste. Thermal processing, in particular, increases lycopene bioavailability, but at the same time promotes lycopene degradation. The aim of the present review is to summarize actual knowledge on the influence of unit operations often used on lycopene stability and bioavailability and to evaluate its nutritional impact.

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Geometrical isomerization of carotenoids in dichloromethane

Cited by 32 publications

References 22 publications

Resonance Raman spectroscopy of carotenoids in Photosystem II core complexes

Resonance Raman spectroscopy of carotenoids in Photosystem II core complexes

Synthesis of a Highly Unsaturated, Stable Hydroxy Peroxide: A Yellow [lrarr2] Blue Color‐Changing Carotenoid Oxidation Product with Leuco Dye Properties

Aspekte der Herstellung haltbarer, lycopinreicher Gemüse- und Obstprodukte

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