Resonance Raman spectra and excitation profiles of tetradesmethyl‐β‐Carotene

Okamoto, Hiromi; Saito, Shigeki; Hamaguchi, Hiro‐o; Tasumi, Mitsuo; Eugster, C. H.

doi:10.1002/jrs.1250150508

Cited by 46 publications

(40 citation statements)

References 24 publications

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“…The series of bands observed between 1486 and 1569 cm 1 can be assigned to a series of polyenic molecules lacking methyl groups. 12,15,27 The fact that methyl groups are not present is confirmed by results concerning the position of the pigments 2 vibration (see below). Thus, we suggest that the pigment in pearls from mollusk H. cumingi certainly contain long polyenic chains, with no methyl groups attached to the chain.…”

Section: Discussionsupporting

confidence: 56%

“…Raman spectra recorded over a wider wavenumber region exhibit the bands in the overtone and combination spectral range as was previously observed by others for pigments containing polyenic chains. 12,21,25,27 However, these peaks are weaker than the fundamental ones; hence, they are of limited interest for our purpose. Luminescence is observed in the green and blue ranges (Figs 2-3) for some colored samples.…”

Section: Resultsmentioning

confidence: 99%

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Determination by Raman scattering of the nature of pigments in cultured freshwater pearls from the mollusk Hyriopsis cumingi

Karampelas¹,

Fritsch²,

Mevellec³

et al. 2006

J Raman Spectroscopy

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The nature of pigments in naturally colored pearls is still under discussion. For this study, Raman scattering measurements were obtained for 30 untreated freshwater cultured pearls from the mollusk Hyriopsis cumingi covering their typical range of colors. The originality of this work is that seven different excitation wavelengths (1064 nm, 676.44 nm, 647.14 nm, 514.53 nm, 487.98 nm, 457.94 nm, 363.80 nm) are used for the same samples at the highest possible resolution. All colored pearls show the two major Raman features of polyenic compounds assigned to double carbon-carbon (C C) -at about 1500 cm −1 -and single carbon-carbon (C-C) -at about 1130 cm −1 -bond stretching mode, regardless of their specific hue. These peaks are not detected in the corresponding white pearls, and therefore seem directly related to the major cause of body color. Additionally, the exact position of C C stretching vibration shows that these compounds are not members of the carotenoid family. Moreover, some changes are observed in intensities, shape and positions of the two main characteristic polyenic peaks from one sample to the next. Similar changes are observed also using several excitation wavelengths for the same point of the same pearl. The exact position of C-C stretching vibration of polyenic molecules depends strongly on the number of double bonds (N) contained in their polyenic chain. Hence, using a constrained decomposition of this band for different excitation wavelengths, up to nine different pigments may be detected in the same pearl. Their general chemical formula is R-(-CH CH-) N -R with N = 6-14. All our colored samples contained at least four pigments (N = 8-11). Different colors are explained by different mixtures, not by a simple change of pigment. The chemical nature of the chain ends is still unknown, because it cannot be detected with Raman scattering. However, it is possible that these polyenes are complexed with carbonate molecules of the nacre. Similar coloration mechanisms are found in products from other living organisms (e.g. parrots feathers). Moreover, it seems that a similar series of pigments is found in other pearls also, as well as in some marine animals living in similar environments (e.g. corals).

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Section: Discussionsupporting

confidence: 56%

Section: Resultsmentioning

confidence: 99%

Determination by Raman scattering of the nature of pigments in cultured freshwater pearls from the mollusk Hyriopsis cumingi

Karampelas¹,

Fritsch²,

Mevellec³

et al. 2006

J Raman Spectroscopy

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“…This is the third line that is enhanced by the resonance effect and is still relatively intense in the spectra of methylated polyenes. The 3 line is significantly decreased in intensity in the spectrum of 20-noraxanthin and is absent in the spectrum of tetradesmethylcarotenoids 36 which positively confirms the assignment and which also demonstrates that this mode is quite pure. 3 rock is weakly coupled to the C(12)OC(13), C(12Ј)OC(13Ј), and C(13Ј)OC(14Ј) stretch vibrations.…”

supporting

confidence: 77%

“…23 This corroborates the fact that for polyacetylenic molecules, and desmethylcarotenes, where methyl groups are lacking, the 2 line is generally 20 cm Ϫ1 lower than for carotenoids of the same chain length. 31,32,35,36 In the spectrum of 20-norastaxanthin the intense 1142 cm Ϫ1 line can be tentatively assigned to a COH bend while the small shoulder at 1162 cm Ϫ1 can contain a significant contribution of demethylated COC stretches.…”

mentioning

confidence: 98%

“…These bands are absent in the spectra of demethylated carotenoids. 36 The intensity of this line has been used to monitor the deviation from planarity of the polyenic chain in carotenoids 38 and in retinals. 27 In this light it is interesting to note that the intensity of these hydrogen out-of-plane STUDIES OF CAROTENOIDS modes is clearly decreased in the spectrum of 20-norastaxanthin, which can be reconciled with an asymmetric structure which is closer to planarity in one half of the molecule than in the other half.…”

mentioning

confidence: 99%

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Semiempirical and Raman spectroscopic studies of carotenoids

et al. 1999

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Analysis of polyethylene wear debris using micro-Raman spectroscopy: A report on the presence of beta-carotene

Hahn

Wolfarth

Parks

1997

J. Biomed. Mater. Res.

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This paper describes micro-Raman spectroscopy of ultra-high molecular weight polyethylene wear debris isolated from revised knee replacements. The novel application of micro-Raman spectroscopy to the analysis of in vivo-generated wear debris was used to evaluate the chemical nature of individual, retrieved polyethylene particles. The analysis revealed the presence of beta-carotene on particles from both synovial fluid and tissue samples. Raman analysis of retrieved polyethylene tibial inserts also revealed localized beta-carotene signals within the primary wear region. In this paper, a mechanism is suggested that may account for the coupling of beta-carotene and polyethylene wear debris. We also discuss the origin of beta-carotene within the implanted joint and the implications that beta-carotene, an anti-oxidant, has for the overall host response to polyethylene orthopedic components.

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Resonance Raman spectra and excitation profiles of tetradesmethyl‐β‐Carotene

Cited by 46 publications

References 24 publications

Determination by Raman scattering of the nature of pigments in cultured freshwater pearls from the mollusk Hyriopsis cumingi

Determination by Raman scattering of the nature of pigments in cultured freshwater pearls from the mollusk Hyriopsis cumingi

Semiempirical and Raman spectroscopic studies of carotenoids

Analysis of polyethylene wear debris using micro-Raman spectroscopy: A report on the presence of beta-carotene

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