Vibrational Spectroscopy as a Tool to Investigate Carotenoids

Dobrowolski, Jan Cz.

doi:10.1002/9781118622223.ch6

Cited by 9 publications

(4 citation statements)

References 143 publications

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“…This effect should be significantly more pronounced for longer polyene chains. Obviously, the presence of trans- or cis- isomers have a large impact on the degree of electron delocalization [ 6 , 10 , 11 , 14 – 16 ]. As a result, all-trans polyenes are significantly better electrical current conductors than their all-cis counterparts [ 11 , 15 , 17 ].…”

Section: Introductionmentioning

confidence: 99%

DFT studies on the structural and vibrational properties of polyenes

et al. 2016

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Detailed density functional theory (DFT) calculations on the structure and harmonic frequencies of model all-trans and all-cis polyenes were undertaken. For the first time, we report on the convergence of selected B3LYP/6-311++G** and BLYP/6-311++G** calculated structural parameters resulting from a systematic increase in polyene size (chains containing 2 to 14 C = C units). The limiting values of the structural parameters for very long chains were estimated using simple three-parameter empirical formulae. BLYP/6-311++G** calculated ν(C = C) and ν(C–C) frequencies for all-trans and all-cis polyenes containing up to 14 carbon–carbon double bonds were used to estimate these values for very long chains. Correction of raw, unscaled vibrational data was performed by comparing theoretical and experimental wavenumbers for polyenes chains containing 3 to 12 conjugated C = C units with both ends substituted by tert-butyl groups. The corrected ν(C = C) and ν(C–C) wavenumbers for all-trans molecules were used to estimate the presence of 9 – 12 C = C units in all-trans polyene pigment in red coral.Graphical abstractDetailed density functional theory (DFT) calculations on the structure and harmonic frequencies of model all-trans and all-cis polyenes were undertaken. For the first time, we report on the convergence of selected B3LYP/6-311++G** and BLYP/6-311++G** calculated structural parameters resulting from a systematic increase in polyene size (chains containing 2 to 14 C=C units). The limiting values of the structural parameters for very long chains were estimated using simple three-parameter empirical formulae.Electronic supplementary materialThe online version of this article (doi:10.1007/s00894-016-2969-1) contains supplementary material, which is available to authorized users.

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Section: Introductionmentioning

confidence: 99%

DFT studies on the structural and vibrational properties of polyenes

et al. 2016

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“…TheECD spectrum reveals quite strong negative-positive bands (from longer to shorter wavelengths), known as bisignate Cotton effects,w ith ac learly accentuated vibrational structure,which was also seen in the UV/Vis spectrum and is typical for carotenoids without conjugated carbonyl groups (such as bC). [30,31] In addition, the RROA shoulder at 967 cm À1 is associated with the symmetric C À H and Cout-of-plane wagging, [32] with asmall contribution due to the b-ring deformations [31] and the CÀCs tretching vibrations. [29] We observed characteristic RROA bands due to typical carotenoid vibrations,namely, n 1 at 1519 cm À1 , n 2 at 1159 cm À1 , n 3 at 1009 cm À1 , and n 4 at 956 cm À1 ,which were assigned to the C=Cstretching, the CÀCs tretching, the in-plane CH 3 rocking,a nd the CÀH out-of-plane wagging motions coupled with the C = Co ut-ofplane torsion modes,respectively.…”

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confidence: 99%

“…[29] We observed characteristic RROA bands due to typical carotenoid vibrations,namely, n 1 at 1519 cm À1 , n 2 at 1159 cm À1 , n 3 at 1009 cm À1 , and n 4 at 956 cm À1 ,which were assigned to the C=Cstretching, the CÀCs tretching, the in-plane CH 3 rocking,a nd the CÀH out-of-plane wagging motions coupled with the C = Co ut-ofplane torsion modes,respectively. [30,31] In addition, the RROA shoulder at 967 cm À1 is associated with the symmetric C À H and Cout-of-plane wagging, [32] with asmall contribution due to the b-ring deformations [31] and the CÀCs tretching vibrations. [33] ARaman imaging study reported that the position of the n 1 band at 1519 cm À1 ,a swell as the n 1 /n 2 ratio of integral intensities (1.005), is specific for the helical crystalline aggregates and the presence of bCi nt he crystal.…”

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confidence: 99%

Chiral Amplification in Nature: Studying Cell‐Extracted Chiral Carotenoid Microcrystals via the Resonance Raman Optical Activity of Model Systems

et al. 2019

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Carotenoid microcrystals,e xtracted from cells of carrot roots and consisting of 95 %o fa chiral b-carotene, exhibit avery intense chiroptical (ECD and ROA) signal. The preferential chirality of crystalline aggregates that consist mostly of achiral building blocks is an ewly observed phenomenon in nature,a nd may be related to asymmetric information transfer from the chiral seeds (small amount of a-carotene or lutein) present in carrot cells.T oc onfirm this hypothesis,w es ynthesized several model aggregates from various achiral and chiral carotenoids.Because of the sergeantand-soldier behavior,asmall number of chiral sergeants (a-carotene or astaxanthin) force the achiral soldier molecules (b-o r1 1,11'-[D 2 ]-b-carotene) to jointly form supramolecular assemblies of induced chirality.T he chiral amplification observed in these model systems confirmed that chiral microcrystals appearing in nature might consist predominantly of achiral building blocks and their supramolecular chirality might result from the co-crystallization of chiral and achiral analogues.

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“…The largest group of conjugated polyenes is the carotenoids, which number over 400 occurring naturally. These have been extensively studied by several chromatographic and spectroscopic techniques, however, the selectivity of Raman spectroscopy towards these conjugated systems has greatly contributed to the identification of carotenoids occurring in marine and terrestrial organisms [3–5,88–95] . In contrast, the chemical structures of the conjugated polyenals have been identified exclusively by Raman spectroscopy, from the earliest studies carried out with octocorals, [3] pearls [3] and parrots’ feathers [5] .…”

Section: Raman Spectroscopy Applied To the Identification Of Polyenesmentioning

confidence: 99%

The Diversity of Linear Conjugated Polyenes and Colours in Nature: Raman Spectroscopy as a Diagnostic Tool

et al. 2020

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This review is centered on the linear conjugated polyenes, which encompasses chromatic biomolecules, such as carotenoids, polyunsaturated aldehydes and polyolefinic fatty acids. The linear extension of the conjugated double bonds in these molecules is the main feature that determines the spectroscopic properties as light‐absorbing. These classes of compounds are responsible for the yellow, orange, red and purple colors which are observed in their parent flora and fauna in nature. Raman spectroscopy has been used as analytical tool for the characterization of these molecules, mainly due to the strong light scattering produced by the delocalized pi electrons in the carbon chain. In addition, conjugated polyenes are one of the main target molecular species for astrobiology, and we also present a brief discussion of the use of Raman spectroscopy as one of the main analytical tools for the detection of polyenes extra‐terrestrially.

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Vibrational Spectroscopy as a Tool to Investigate Carotenoids

Cited by 9 publications

References 143 publications

DFT studies on the structural and vibrational properties of polyenes

DFT studies on the structural and vibrational properties of polyenes

Chiral Amplification in Nature: Studying Cell‐Extracted Chiral Carotenoid Microcrystals via the Resonance Raman Optical Activity of Model Systems

The Diversity of Linear Conjugated Polyenes and Colours in Nature: Raman Spectroscopy as a Diagnostic Tool

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