Characterization of the metabolism of 5-hydroxymethylfurfural by human intestinal microflora using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry

5-Hydroxymethylfurfural (5-HMF), isolated from a wide range of heat-processed foods and medicines, exhibits a variety of pharmacological activities and biological effects. The human intestinal microbiota might have an important impact on drug metabolism and ultimately on the drug oral bioavailability. However, the interactions of this active compound with intestinal bacteria are not clear. In this work, different pure bacteria from human feces were isolated and used to investigate their conversion capability of 5-HMF compared with the mixed intestinal bacteria. The ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF/MS) technique combined with the Metabolynx™ software was applied to analyze 5-HMF and its metabolites. Compared with blank samples, the parent compound and three metabolites were detected and tentatively identified based on the characteristics of their protonated ions. The metabolites were produced by three main metabolic pathways including methylation, acetylation and glucuronidation. 5-HMF could be converted to its methylated product (M1) by the majority of the isolated intestinal bacteria and the mixed intestinal bacteria. However, acetylated 5-HMF (M2) was obtained from the minor bacterial samples like Bacteroides sp. 45 and glucuronidated 5-HMF (M3) was detected only in the sample of Escherichia sp. 88. The metabolic routes and metabolites of 5-HMF produced by human intestinal bacteria were reported for the first time. This study will be very helpful for further investigation of the pharmacokinetic research of 5-HMF in vivo.