Metabolomic profiles of A-type procyanidin dimer and trimer with gut microbiota in vitro
Wanbing Chen, Zhang Li, Li Zhao, Fangfang Yan, Xiaoling Zhu, Qun Lu, Rui Liu
Abstract
Although intestinal microbiota plays an important role in the metabolism of procyanidins, the microbial metabolic pathway of A-type procyanidins remains elusive. In this study, A-type dimer procyanidin A1 [EC-(2β-O-7,4β-8)-C] and trimer PPD [EC-(4β-6)-EC-(2β-O-7,4β-8)-C] were incubated with rat faecal microbiota in vitro, and their metabolomic profiles were analyzed by UPLC-QTOF/MS. Multivariate statistical analysis identified 24 and 30 discriminant metabolites for A1 and PPD, respectively. The C-ring opened catabolites of procyanidin A1 and PPD and the typical phenolic acid metabolites were identified, including phenylacetic acid, (4′-hydroxyphenyl)acetic acid, 3-phenylpropanoic acid, 3-(4′-hydroxyphenyl)propanoic acid, 3-(3′,4′-dihydroxyphenyl)propanoic acid, and 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone. Notably, procyanidin A1 and (epi)catechin were identified from the metabolites of PPD; however, no (epi)catechin was found in the metabolites of procyanidin A1, indicating that the faecal microbiota can destroy B-type linkage (C4-C6 interflavan bond) but not A-type linkage (C4-C8 and additional C2-O-C7 interflavan bond) in the metabolism of A-type procyanidins.