Intestinal Metabolism of Two A-type Procyanidins Using the Pig Cecum Model: Detailed Structure Elucidation of Unknown Catabolites with Fourier Transform Mass Spectrometry (FTMS)

NRW Graduate School of Chemistry, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 10, 48149 Münster, Germany.
Journal of Agricultural and Food Chemistry (Impact Factor: 2.91). 12/2011; 60(3):749-57. DOI: 10.1021/jf203927g
Source: PubMed


Procyanidins, as important secondary plant metabolites in fruits, berries, and beverages such as cacao and tea, are supposed to have positive health impacts, although their bioavailability is yet not clear. One important aspect for bioavailability is intestinal metabolism. The investigation of the microbial catabolism of A-type procyanidins is of great importance due to their more complex structure in comparison to B-type procyanidins. A-type procyanidins exhibit an additional ether linkage between the flavan-3-ol monomers. In this study two A-type procyanidins, procyanidin A2 and cinnamtannin B1, were incubated in the pig cecum model to mimic the degradation caused by the microbiota. Both A-type procyanidins were degraded by the microbiota. Procyanidin A2 as a dimer was degraded by about 80% and cinnamtannin B1 as a trimer by about 40% within 8 h of incubation. Hydroxylated phenolic compounds were quantified as degradation products. In addition, two yet unknown catabolites were identified, and the structures were elucidated by Fourier transform mass spectrometry.

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    • "In cases where only low amounts of intermediates were secreted by the mutant strains, HPLC, in combination with FTMS/MS fragmentation, was used for unequivocal structure elucidation. Previous studies of Engemann et al. could show that this is a good tool for structure elucidation (Engemann et al., 2012). As expected, Dfus1 and Dfus2-9 deletion mutants that have lost the PKS/NRPS-encoding gene fus1 or all cluster genes except for fus1, respectively, did not produce any fusarin C "
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