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Chlorophyll breakdown in senescent banana leaves: catabolism reprogrammed for biosynthesis of persistent blue fluorescent tetrapyrroles.

Vergeiner C, Banala S, Kräutler B - Chemistry (2013)

Bottom Line: Amazingly, in the leaves of banana plants, persistent hmFCCs were identified that accounted for about 80 % of the chlorophyll broken down, and yellow leaves of M. acuminata display a strong blue luminescence.The structures of eight hmFCCs from banana leaves were analyzed by spectroscopic means.As expressed earlier in related studies, the present findings call for attention, as to still elusive biological roles of these linear tetrapyrroles.

View Article: PubMed Central - PubMed

Affiliation: Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck (Austria).

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NMR analysis of the sugar ester moieties at the propionic acid side chain of: A) Ma-FCC-64, B) Ma-FCC-63, and C) Ma-FCC-69 (R=(3,4-dihydroxyphenyl)-ethyl group) based on 2D correlations (600 MHz, CD3CN/D2O 9:1 (v/v) or CD3CN (Ma-FCC-69), 10 °C). Left: Graphical representations of assigned 1H NMR signals and of homonuclear 1H,1H correlations: bold lines refer to COSY spectra, arrows to ROESY spectra. Right: Assigned signals of 13C atoms from heteronuclear 1H,13C correlations; shadowed boxes indicate 13C assignments from direct correlations (HSQC spectra), arrows point to 13C assignments from long-range couplings with H atoms, as seen in HMBC spectra.
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fig06: NMR analysis of the sugar ester moieties at the propionic acid side chain of: A) Ma-FCC-64, B) Ma-FCC-63, and C) Ma-FCC-69 (R=(3,4-dihydroxyphenyl)-ethyl group) based on 2D correlations (600 MHz, CD3CN/D2O 9:1 (v/v) or CD3CN (Ma-FCC-69), 10 °C). Left: Graphical representations of assigned 1H NMR signals and of homonuclear 1H,1H correlations: bold lines refer to COSY spectra, arrows to ROESY spectra. Right: Assigned signals of 13C atoms from heteronuclear 1H,13C correlations; shadowed boxes indicate 13C assignments from direct correlations (HSQC spectra), arrows point to 13C assignments from long-range couplings with H atoms, as seen in HMBC spectra.

Mentions: The sugar moieties of Ma-FCC-63 and Ma-FCC-64 were further characterized as glucopyranose units, based on analysis of the values of the 1H,1H coupling constants within the two pyranose units, NOE correlations from 1H,1H ROESY spectra and of the 1H and 13C chemical shift data (Figure 6), and comparison with those of reference compounds.[33–36] Indeed, these two (slowly interconverting) FCCs were thus deduced to differ only by the stereochemistry at their anomeric centers. Accordingly, Ma-FCC-63 was identified as a 31,32-didehydro-82-hydroxy-132-(methoxycarbonyl)-173-(6′-β-glucopyranosyl)-1,4,5,10,17,18,20,22-octahydro-4,5-seco-(22H)-phytoporphyrin, and Ma-FCC-64 as the 173-(6′-α-glucopyranosyl) anomer.


Chlorophyll breakdown in senescent banana leaves: catabolism reprogrammed for biosynthesis of persistent blue fluorescent tetrapyrroles.

Vergeiner C, Banala S, Kräutler B - Chemistry (2013)

NMR analysis of the sugar ester moieties at the propionic acid side chain of: A) Ma-FCC-64, B) Ma-FCC-63, and C) Ma-FCC-69 (R=(3,4-dihydroxyphenyl)-ethyl group) based on 2D correlations (600 MHz, CD3CN/D2O 9:1 (v/v) or CD3CN (Ma-FCC-69), 10 °C). Left: Graphical representations of assigned 1H NMR signals and of homonuclear 1H,1H correlations: bold lines refer to COSY spectra, arrows to ROESY spectra. Right: Assigned signals of 13C atoms from heteronuclear 1H,13C correlations; shadowed boxes indicate 13C assignments from direct correlations (HSQC spectra), arrows point to 13C assignments from long-range couplings with H atoms, as seen in HMBC spectra.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC3814416&req=5

fig06: NMR analysis of the sugar ester moieties at the propionic acid side chain of: A) Ma-FCC-64, B) Ma-FCC-63, and C) Ma-FCC-69 (R=(3,4-dihydroxyphenyl)-ethyl group) based on 2D correlations (600 MHz, CD3CN/D2O 9:1 (v/v) or CD3CN (Ma-FCC-69), 10 °C). Left: Graphical representations of assigned 1H NMR signals and of homonuclear 1H,1H correlations: bold lines refer to COSY spectra, arrows to ROESY spectra. Right: Assigned signals of 13C atoms from heteronuclear 1H,13C correlations; shadowed boxes indicate 13C assignments from direct correlations (HSQC spectra), arrows point to 13C assignments from long-range couplings with H atoms, as seen in HMBC spectra.
Mentions: The sugar moieties of Ma-FCC-63 and Ma-FCC-64 were further characterized as glucopyranose units, based on analysis of the values of the 1H,1H coupling constants within the two pyranose units, NOE correlations from 1H,1H ROESY spectra and of the 1H and 13C chemical shift data (Figure 6), and comparison with those of reference compounds.[33–36] Indeed, these two (slowly interconverting) FCCs were thus deduced to differ only by the stereochemistry at their anomeric centers. Accordingly, Ma-FCC-63 was identified as a 31,32-didehydro-82-hydroxy-132-(methoxycarbonyl)-173-(6′-β-glucopyranosyl)-1,4,5,10,17,18,20,22-octahydro-4,5-seco-(22H)-phytoporphyrin, and Ma-FCC-64 as the 173-(6′-α-glucopyranosyl) anomer.

Bottom Line: Amazingly, in the leaves of banana plants, persistent hmFCCs were identified that accounted for about 80 % of the chlorophyll broken down, and yellow leaves of M. acuminata display a strong blue luminescence.The structures of eight hmFCCs from banana leaves were analyzed by spectroscopic means.As expressed earlier in related studies, the present findings call for attention, as to still elusive biological roles of these linear tetrapyrroles.

View Article: PubMed Central - PubMed

Affiliation: Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck (Austria).

Show MeSH
Related in: MedlinePlus