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  • 1975-1979  (6)
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  • 1
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Search for the Presence in Egg Yolk, in Flowers of Caltha palustris and in Autumn Leaves of 3′-Epilutein ( =(3R,3′S,6′R)-β,ε-Carotene-3,3′-diol) and 3′,O-Didehydrolutein ( =(3R,6′R)-3-Hydroxy-β,ε-carotene-3′-one)3′.O-Didehydrolutein ( =(3R, 6′R)-3-hydroxy-β,ε-carotene-3′-one; 2) has been detected in egg yolk and in flowers of Caltha palustris. This is the first record for its occurrence in a plant. The compound shows a remarkable lability towards base; therefore, it may have been overlooked til now, because it is destroyed under the usual conditions of saponification of the carotenoid-esters. One of the many products formed from 2 with 1% KOH in methanol has been purified and identified as the diketone 3 ( =(3R)-3-hydroxy-4′, 12′-retro-β,β-carotene-3′,12′-dione). The identification of this transformation product from lutein might throw a new light on the metabolism of this important carotenoid in green plants.3′-Epilutein ( =(3R,3′S,6′R)-β,ε-carotene-3,3′-diol; 1) was not detected in egg yolk, but is present besides lutein in flowers of C. palustris, thus confirming an earlier report of the occurrence of an isomeric (possibly epimeric) lutein (‘calthaxanthin’) in that plant [21].We were not able to detect even traces of 1 or 2 in the carotenoid fraction from autumn leaves of Prunus avium (cherry), Parrotia persica, Acer montanum (maple) and yellow needles of Larix europaea (larch).α-Cryptoxanthin (4), a very rare carotenoid, was isolated in considerable quantity for the first time from flowers of C. palustris.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 2780-2788 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carotenoids from Marine Sponges (Porifera): Isolation and Structure of the Seven Main Carotenoids from Agelas schmidtiiThe following carotenoids were identified in the marine sponge Agelas schmidtii: α-carotene ((6′R)-β, ε-carotene (1)), isorenieratene (ϕ,ϕ-carotene (2)), trikentriorhodin (3,8-dihydroxy-κ,χ-caroten-6-one (3)) and zeaxanthin ((3R, 3′R)-β, β-carotene-3, 3′-diol (4)). In addition, three previously unknown carotenoids called agelaxanthin A, B and C were isolated. Spectroscopical and chemical structure elucidation showed agelaxanthin A to be (3 R)-β, ϕ-caroten-3-ol (6) and agelaxanthin C to be a methoxy-19,3′,8′-trihydroxy-7,8-didehydro-β, κ-caroten-6′-one (7) with the methoxy group at C (2), C (3) or C (4). The limited data on age-laxanthin B were compatible with the structure of a 19-O-methyl derivative of agelaxanthin C.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 58 (1975), S. 89-95 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The conversion of the allenic end group 1 on HCl/CHCl3 treatment to the acetylenic 2 resp. to the chlorinated end group 3 previously reported has been confirmed using neoxanthin (4a) and its diacetate (4b). Analogous HBr treatment provided the corresponding brominated end group. Chemical and spectroscopical evidence for the position of the halogen atom at C(7) is given.Transformation to allenic anhydro products and acetylenic products on treatment of neoxanthin diacetate (4b) with phosphorous oxychloride in pyridine, as well as dehydration and chlorine substitution of neoxanthin (4a) are reported. These results are consistent with previous observations on related carotenoids.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 1962-1968 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Absolute Configuration of α-Doradexanthin and of Fritschiellaxanthin, a New Carotenoid from Fritschiella tuberosa IYENG.Fritschiellaxanthin, a new oxocarotenoid produced by the green alga Fritschiella tuberosa, in a nitrogen-deficient medium is now shown to be (3 S, 3′ R, 6′ R)-3, 3′-dihydroxy-β, ∊-caroten-4-one (4b). It is not identical with α-Doradexanthin (5b) previously found in goldfish (Carassius auratus) and to which we assign the (3 S, 3′ S, 6′ R)-chirality. Consequently, fritschiellaxanthin and α-Doradexanthin are C(3′)-epimers of lutein-4-on. Furthermore, the so-called ′lutein′ from goldfish has now been found to be identical with 3′-epilutein (3). Therefore, fritschiellaxanthin is probably biogenetically derived from lutein (2), whereas α-Doradexanthin is formed from 3′-epilutein (3) with 3, O-didehydrolutein (=(3R, 6′R)-3-hydroxy-β, ∊-caroten-3′-one10) as a precursor. For comparison, optically active 10 and 3 have been prepared from lutein (2) and are fully characterised.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1754-1757 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carotenoids in petals of Rosa foetidaThe petals of Rosa foetida, HERRM., a species of prime importance in the history of breeding true yellow garden roses, have been analysed for carotenoids for the first time. The following components were identified: β-carotene (1, 4,5%), lutein (2, 8%), zeaxanthin (3, 17,4%), auroxanthin (4, 30,8%), luteoxanthin (5, 21,9%), violaxanthin (6, 9,2%) and neochrome (7, 4,1%). Not identified carotenoids (4,1%) contained probably mutatoxanthin, antheraxanthin and apocarotenals. Thus the brillant yellow colour of R. foetida flowers is due mainly to carotenoid epoxides.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Überprüfung einiger Originalpräparate von Taraxanthin.Das von R. Kuhn & E. Lederer 1931 entdeckte und seither in zahlreichen höheren Pflanzen nachgewiesene Taraxanthin wird anhand von Originalpräparaten aus Impatiens nolitangere L., Ranunculus acer L. sowie durch erneute Isolierung aus Taraxacum officinale L. mit modernen Methoden untersucht. Taraxanthin erweist sich als Gemisch von Xanthophyll-epoxid (= Lutein-epoxid; 2) oder dessen Umlagerungsprodukten und O4-Carotinoiden bekannter Struktur. Das aus Taraxacum erhaltene Präparat setzt sich aus 2 (73%), Flavoxanthin (4, 13%) und Chrysanthemaxanthin (4 (C(8)-Epimer), 14%) zusammen. Nicht identifizierte Carotinoide in den untersuchten Präparaten betragen weniger als 3,5%. Ein in kleiner Menge in R. acer nachgewiesenes Carotinoid ist wahrscheinlich 5,6-Dihydroxy-5,6-dihydrolutein (6).Der Name Taraxanthin als Bezeichnung für ein einheitliches Carotinoid soll aufgegeben werden.
    Type of Medium: Electronic Resource
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