High-performance liquid chromatographic separation and isolation of the methanolic allomerization products of chlorophyll a

Kuronen, Pirjo; Hyvärinen, Kristiina; Hynninen, Paavo H.; Kilpeläinen, Ilkka

doi:10.1016/0021-9673(93)83068-4

Cited by 39 publications

(41 citation statements)

References 40 publications

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“…In fact, the common technique to produce the 13 2 -hydroxy chlorophyll-a and -b used for MS analyses is the methanolic allomerization [21][22][23][24], which leads to non-specific oxidation and calls for large volumes of initial substrates, because the hydroxyl derivatives are produced in minor amounts. Coming to the oxidation to lactone group, traditional methods including exposing chlorophyll solutions in methanol to air [22][23][24][25][26] or exceptionally alkaline treatment [27] can only guarantee the yield of 15 1 -methoxy-lactone chlorophyll but not 15 1 -hydroxy-lactone counterpart, which is the particular compound present in natural food resources or physiological tissues. Considering the lack of protocols to produce conveniently, the natural chlorophyll derivatives with hydroxyl function at C13 2 or at C15 1 (lactone chlorophyll derivatives), it is of great importance to establish specific reactions pathways to produce a concrete oxidation and to develop new methods to obtain specific chlorophyll derivative standards.…”

Section: Introductionmentioning

confidence: 99%

Development of an accurate and high-throughput methodology for structural comprehension of chlorophylls derivatives. (I) Phytylated derivatives

Chen

Ríos

Pérez‐Gálvez

et al. 2015

Journal of Chromatography A

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Phytylated chlorophyll derivatives undergo specific oxidative reactions through the natural metabolism or during food processing or storage, and consequently pyro-, 13(2)-hydroxy-, 15(1)-hydroxy-lactone chlorophylls, and pheophytins (a and b) are originated. New analytical procedures have been developed here to reproduce controlled oxidation reactions that specifically, and in reasonable amounts, produce those natural target standards. At the same time and under the same conditions, 16 natural chlorophyll derivatives have been analyzed by APCI-HPLC-hrMS(2) and most of them by the first time. The combination of the high-resolution MS mode with powerful post-processing software has allowed the identification of new fragmentation patterns, characterizing specific product ions for some particular standards. In addition, new hypotheses and reaction mechanisms for the established MS(2)-based reactions have been proposed. As a general rule, the main product ions involve the phytyl and the propionic chains but the introduction of oxygenated functional groups at the isocyclic ring produces new and specific productions and at the same time inhibits some particular fragmentations. It is noteworthy that all b derivatives, except 15(1)-hydroxy-lactone compounds, undergo specific CO losses. We propose a new reaction mechanism based in the structural configuration of a and b chlorophyll derivatives that explain the exclusive CO fragmentation in all b series except for 15(1)-hydroxy-lactone b and all a series compounds.

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Section: Introductionmentioning

confidence: 99%

Development of an accurate and high-throughput methodology for structural comprehension of chlorophylls derivatives. (I) Phytylated derivatives

Chen

Ríos

Pérez‐Gálvez

et al. 2015

Journal of Chromatography A

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“…1) autoxidation products, however, 13 2 ‐hydroxychlorophyll a (13 2 ‐HO‐chl a ; 1 a (i) and (ii)), 13 2 ‐methoxychlorophyll a (13 2 ‐MeO‐chl a ; 1 a (iii) and (iv)), 15 1 ‐methoxylactonechlorophyll a (15 1 ‐MeO‐lact‐chl a ; 2 b (i) and (ii)) and Mg‐purpurin‐7 dimethyl phytyl ester ( 1 c (i)), formed in methanolic solution, have only been elucidated more recently. 2 15 1 ‐MeO‐lact‐chl a , 13 2 ‐MeO‐chl a 2,3 and 13 2 ‐HO‐chl a 3–5 exist as two diastereomers differing at position C‐13 2 or C‐15 1 . Recently, full spectral assignment including the designation of the stereochemical configurations of three pairs of diastereomers has been achieved by complete assignment of the 1 H and 13 C nuclear magnetic resonance (NMR) and 2D ROESY spectra 6.…”

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confidence: 99%

Identification of diastereomeric chlorophyll allomers by atmospheric pressure chemical ionisation liquid chromatography/tandem mass spectrometry

Walker¹,

Chi²,

Keely³

2003

Rapid Comm Mass Spectrometry

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Atmospheric pressure chemical ionisation liquid chromatography/mass spectrometry (APCI-LC/MS) has been used for identification of the epimers of hydroxy, methoxy and methoxylactone allomers of chlorophyll a (13(2)-HO-chl a, 13(2)-MeO-chl a and 15(1)-MeO-lact-chl a), the hydroxy allomer of bacteriochlorophyll a (13(2)-HO-bchl a) and the hydroxy and methoxylactone allomers of bacterioviridin a (13(2)-HO-bvir a and 15(1)-MeO-lact-bvir a). The APCI mass spectra show that facile fragmentations involve the methoxyl or hydroxyl groups at the C-13(2) or C-15(1) chiral centres. Losses involving the C-13(2) or C-15(1) hydroxyl or methoxyl groups occur more easily from the S-epimer than from the R-epimer due to the greater relief of the steric strain associated with interaction with the bulky C-17 substituent. The differences in mass spectrometric fragmentation can be used as a diagnostic tool for the assignment of the stereochemical configuration at the C-13(2) or C-15(1) chiral centres.

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“…Chlorophyll allomers have been characterised in previous papers. 11,15,23,24 The next phase is to scale the data as described above, and then perform PCA, retaining the three most significant principal components. Three-dimensional (3-D) plots of scores and loadings were generated, and rotated to emphasise the most important features.…”

Section: Resultsmentioning

confidence: 99%

Principal components scores and loadings plots for visualisation of the electrospray ionisation liquid chromatography mass spectra of a mixture of chlorophyll degradation products at different cone voltages

Zissis

Brereton

Dunkerley

1999

Rapid Commun. Mass Spectrom.

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Positive ion electrospray liquid chromatography mass spectrometry was performed on a mixture of allomers obtained from the degradation of chlorophyll a, at three cone voltages. An approach is described for obtaining principal components loadings and scores plots, involving mass selection, normalisation and standardisation of the data, principal components analysis and three dimensional projections. The loadings plots group ions which are assigned to five major compounds in the mixture by reference to the scores. At higher cone voltage fragmentation and differentiation between compounds with identical molecular weights is observed.

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High-performance liquid chromatographic separation and isolation of the methanolic allomerization products of chlorophyll a

Cited by 39 publications

References 40 publications

Development of an accurate and high-throughput methodology for structural comprehension of chlorophylls derivatives. (I) Phytylated derivatives

Development of an accurate and high-throughput methodology for structural comprehension of chlorophylls derivatives. (I) Phytylated derivatives

Identification of diastereomeric chlorophyll allomers by atmospheric pressure chemical ionisation liquid chromatography/tandem mass spectrometry

Principal components scores and loadings plots for visualisation of the electrospray ionisation liquid chromatography mass spectra of a mixture of chlorophyll degradation products at different cone voltages

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