Stereoisomers of fucoxanthin

Bernhard, Kurt; Moss, G. P.; Tóth, Gy.; Weedon, B. C. L.

doi:10.1016/s0040-4039(01)92040-4

Cited by 28 publications

(7 citation statements)

References 5 publications

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“…Da die absolute Konfiguration und, wie die hier mitgeteilten IH-NMR.-Daten zeigen, auch die Konformation der Endgruppen von 1 und 2 identisch sind, bedarf somit jede Theorie, die das CD.-Spektrum allein aus der Konfiguration des chiralen Zentrums und der Konformation der Endgruppen zu erklaren sucht [8], einer Erweiterung. Eine Vorzeichenumkehr beim Uber- gang von all-trans-zu cis-Carotinoiden wurde iibrigens schon friiher bei Fucoxanthin [19] und Violaxanthin [20] beobachtet. Demnach sind die Verhaltnisse doch komplizierter als bisher angenommen wurde.…”

Section: Circulardichroismus (Cdunclassified

¹H‐NMR.‐, ¹³C‐NMR.‐, UV.‐ und CD.‐Daten von synthetischem (3S, 3′S)‐Astaxanthin, seinem 15‐cis‐Isomeren und einigen analogen Verbindungen

Englert

Kienzle

Noack

1977

Helvetica Chimica Acta

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Herrn Professor Dr. Walter Bogurh zum 60. Geburtstag gewidmet (10.111. 77) lH-NMR., 13C-NMR., UV. and CD. spectral data of synthetic (3S, 3's)-astaxanthin, its 15-cis isomer, and some related compounds Summary 1H-NMR., 13C-NMR., UV. and CD. spectra are reported for synthetic (3 S, 3's)-astaxanthin (l), its 15-cis isomer (2), its diacetate (3), and the 15,15'-didehydro compound (5). These data prove the identity of the synthetic and the naturally occuring compound 1. A full interpretation of the lH-and 13C-NMR. spectra is given and confirms the configuration of all the double bonds. The conformation of the cyclohexene end group of all the compaunds is shown to be identical. The signs of the different CD. maxima of 15-cis-astaxanthin are found to be opposite to those of the all-trans compound.Einleitung. - Obwohl das Vorkommen von Astaxanthin sehr oft in der Literatur erwahnt wird, geschieht dessen Nachweis meist nur durch UV.-und Massen-Spektroskopie. Da haufig freies Astaxanthin und dessen Mono-und Di-ester nebeneinander anzutreffen sind, erfolgt deren gemeinsamer Nachweis in vielen Fallen spektroskopisch sogar erst

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Section: Circulardichroismus (Cdunclassified

¹H‐NMR.‐, ¹³C‐NMR.‐, UV.‐ und CD.‐Daten von synthetischem (3S, 3′S)‐Astaxanthin, seinem 15‐cis‐Isomeren und einigen analogen Verbindungen

Englert

Kienzle

Noack

1977

Helvetica Chimica Acta

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“…spectrum of 9-cis-neoxanthin and then in the CD. spectrum of some fucoxanthin stereoisomers [6]. The CD.…”

Section: Discussionmentioning

confidence: 99%

“…It has been argued here that the CD. spectrum of a carotenoid and also its remarkable sign inversion between the all-trans and the mono-cis form arises from the presence of a hindered C (6), C (7)-bond linking the optically active end-ring to the remainder of the carotenoid chain. In the carotenoids which have a 7-8 triple bond, such as asterinic acid (7,8,7', 8'-tetradehydroastaxanthin), the conjugated chain appears to be much less strongly sterically coupled to the end-ring.…”

Section: Discussionmentioning

confidence: 99%

“…The first two groups of molecules have values of D such that the double bond C(7),C(8) is lying in a range between 28" and 62" away from the s-cis position. These molecules constitute two groups because C (8) can lie either above the plane C(1), C(5), C (6) or below this plane (that is, C(8) and C(2) on the same or on the opposite sides of that plane). The two sides of this plane are non-equivalent because of the conformation of the end-ring.…”

Section: Discussionmentioning

confidence: 99%

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Conformation and Optical Activity of all‐trans, mono‐cis, and di‐cis Carotenoids: Temperature Dependent Circular Dichroism

Noack

Thomson

1979

Helvetica Chimica Acta

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SummaryThe CD. spectra of carotenoids with an asymmetric centre at C(3) have the following unusual features: 1) All-trans and di-cis compounds with two end-rings, at least one of which possesses an asymmetric C-atom, have very similar CD. spectra, whereas the corresponding mono-cis compounds give mirror-image CD. spectra; 2) In carotenoids or apocarotenoids with only one end-ring all-trans and mono-cis compounds have the same CD. spectra; 3) The CD. spectra of such carotenoids are strongly temperature dependent either increasing in magnitude or completely changing in sign upon cooling.These properties have been rationalized with the aid of a model with takes the total chromophore of the carotenoid as being intrinsically chiral with symmetry C, . It seems that the chirality arises not only from the presence of the hydroxyl group of an asymmetric carbon atom, C (3), which occupies an equatorial position thereby locking the conformation of the end-ring, but also from the steric hindrance across the formal single bond C(6),C(7), linking the end-ring to tlhe chain and thus creating a chiral n-system. (The twist about the C(6),C(7)-bond acquires a handedness because of the predominance of one conformational form of the end-ring. In this way, the double bonds of the end-ring become: twisted out of the plane of the chain with one hand predominating. Thus the whole conjugated system becomes chiral). The reversal of sign between the trans (and dii-cis) and mono-cis compounds is due to a tilt of the 2-fold symmetry axis and thereby a change of chirality. The temperature dependence stems from the varying population of forms of different twist of the end-group relative to the chain.Compounds with 7,8-triple bonds also show distinct CD. spectra and a sign change between all-trans and mono-cis isomers in addition to temperature dependence. The latter property demonstrates that some steric hindrance between the end-ring and the main chain is present in these compounds.Some suggestions for the origins of the sign patterns and band intensities of the CD. and absorption spectra are included.

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“…In 1967 József Szabolcs led the carotenoid research group in Pécs. The group continued fruitful collaboration with a research group in London [45][46][47][48]. As a result of this important cooperation, a basic article about Optical Rotatory Dispersion of Carotenoids was published in 1969 [49], which allowed the determination of the absolute configuration of carotenoids.…”

Section: Open-column Chromatographymentioning

confidence: 99%

Isolation and Analysis of Carotenoids in Hungary from Zechmeister until Today

et al. 2022

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László Zechmeister, one of the most important pioneers of carotenoid chemistry, died 50 years ago. He founded a carotenoid research group in Pécs (Hungary), which is the only place in the world where carotenoid research has been conducted continuously over the past 95 years. This review presents the life of Zechmeister and gives a summary about the evolution of the methods of analysis, isolation, and structure elucidation of carotenoids from the 1930s until today, based on the results of the research group founded by Zechmeister.

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Stereoisomers of fucoxanthin

Cited by 28 publications

References 5 publications

¹H‐NMR.‐, ¹³C‐NMR.‐, UV.‐ und CD.‐Daten von synthetischem (3S, 3′S)‐Astaxanthin, seinem 15‐cis‐Isomeren und einigen analogen Verbindungen

¹H‐NMR.‐, ¹³C‐NMR.‐, UV.‐ und CD.‐Daten von synthetischem (3S, 3′S)‐Astaxanthin, seinem 15‐cis‐Isomeren und einigen analogen Verbindungen

Conformation and Optical Activity of all‐trans, mono‐cis, and di‐cis Carotenoids: Temperature Dependent Circular Dichroism

Isolation and Analysis of Carotenoids in Hungary from Zechmeister until Today

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Stereoisomers of fucoxanthin

Cited by 28 publications

References 5 publications

1H‐NMR.‐, 13C‐NMR.‐, UV.‐ und CD.‐Daten von synthetischem (3S, 3′S)‐Astaxanthin, seinem 15‐cis‐Isomeren und einigen analogen Verbindungen

1H‐NMR.‐, 13C‐NMR.‐, UV.‐ und CD.‐Daten von synthetischem (3S, 3′S)‐Astaxanthin, seinem 15‐cis‐Isomeren und einigen analogen Verbindungen

Conformation and Optical Activity of all‐trans, mono‐cis, and di‐cis Carotenoids: Temperature Dependent Circular Dichroism

Isolation and Analysis of Carotenoids in Hungary from Zechmeister until Today

Contact Info

Product

Resources

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¹H‐NMR.‐, ¹³C‐NMR.‐, UV.‐ und CD.‐Daten von synthetischem (3S, 3′S)‐Astaxanthin, seinem 15‐cis‐Isomeren und einigen analogen Verbindungen

¹H‐NMR.‐, ¹³C‐NMR.‐, UV.‐ und CD.‐Daten von synthetischem (3S, 3′S)‐Astaxanthin, seinem 15‐cis‐Isomeren und einigen analogen Verbindungen