Forskning
August 17, 2018
In vitro gut metabolism of [U-13 C]-quinic , the other hydrolosis product of chlorogenic acid
M N Pinta et al, 2018. In vitro gut metabolism of [U-13 C]-quinic , the other hydrolosis product of chlorogenic acid, Mol Nutr Food Research, published online.
ABSTRACT:
SCOPE: Quinic acid in its free form is broadly abundant in plants, and can accumulate in copious amounts in coffee, tea and certain fruits. However, it has been mostly studied as chlorogenic acid, an ester of caffeic and quinic acids. When chlorogenic acid reaches the colon, it is hydrolysed by microbial esterases releasing caffeic and quinic acids. While biotransformation of chlorogenic and caffeic acids have been elucidated by in vitro and in vivo studies, the gut metabolism of quinic acid has been so far overlooked.
METHODS AND RESULTS: In this study, [U-13 C]-quinic acid was submitted to a colonic model using human faecal microbiota for assessing its metabolic fate. The metabolite profiles formed along microbial biotransformation were monitored by a combined metabolomics approach, using both two-dimensional gas chromatography- and ultra-high performance liquid chromatography- mass spectrometry. Six metabolic intermediates were identified by incorporation of isotopic label.
CONCLUSION: Two parallel degradation pathways could be proposed: i/ an oxidative route, leading to aromatization and accumulation of protocatechuic acid, and a ii/ a reductive route, including dehydroxylation to cyclohexane carboxylic acid. Elucidating the biotransformation of food bioactives by the gut microbiota is of relevance for understanding nutrition, inter-individual variability and potential effects on human metabolism.
