Chlorophyll breakdown in senescent banana leaves: catabolism reprogrammed for biosynthesis of persistent blue fluorescent tetrapyrroles.
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.
Affiliation: Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck (Austria).Show MeSH
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Mentions: ESI-MS spectra of both, Ma-FCC-63 and Ma-FCC-64, indicated pseudo-molecular ions [M+H]+ at m/z 807.2, consistent with a (common) molecular formula of C41H50N4O13. Loss of up to three water molecules was observed at m/z 789.3, 771.3 and 753.3. A fragment at m/z 654.3 indicated loss of ring B. 1H NMR spectra (600 MHz) of Ma-FCC-63, as well as of Ma-FCC-64, in CD3CN/D2O 9:1 (v/v) at 10 °C showed each a set of the characteristic signals of the tetrapyrrole moiety, among them signals at low field due to a formyl and a vinyl group, three singlets and one doublet of four methyl groups at high field, as well as a sharp singlet of the methyl ester group at 3.65 ppm (Figure 5).
Affiliation: Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck (Austria).