title: Analysis of the metabolites of isorhamnetin 3-O-glucoside produced by human intestinal flora in vitro by applying ultraperformance liquid chromatography/quadrupole time-of-flight mass spectrometry.
abstract: Isorhamnetin 3-O-glucoside, which is widely contained in many vegetables and rice, is expected to be metabolized by intestinal microbiota after digestion, which brings about the profile of its pharmacological effect. However, little is known about the interactions between this active ingredient and the intestinal flora. In this study, the preculture bacteria and GAM (general anaerobic medium) broth with isorhamnetin 3-O-glucoside were mixed for 48 h of incubation. Ultraperformance liquid chromatography/quadrupole time-of-flight mass spectrometry was used for analysis of the metabolites of isorhamnetin 3-O-glucoside in the corresponding supernatants of fermentation. The parent and five metabolites were found and preliminarily identified on the basis of the chromatograms and characteristics of their protonated ions. Four main metabolic pathways, including deglycosylation, demethoxylation, dehydroxylation, and acetylation, were summarized to explain how the metabolites were converted. Acetylated isorhamnetin 3-O-glucoside and kaempferol 3-O-glucoside were detected only in the sample of Escherichia sp. 12, and quercetin existed only in the sample of Escherichia sp. 4. However, the majority of bacteria could metabolize isorhamnetin 3-O-glucoside to its aglycon isorhamnetin, and then isorhamnetin was degraded to kaempferol. The metabolic pathway and the metabolites of isorhamnetin 3-O-glucoside yielded by different isolated human intestinal bacteria were investigated for the first time. The results probably provided useful information for further in vivo metabolism and active mechanism research on isorhamnetin 3-O-glucoside.
authors.affiliation: Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine , 138 Xianlin Road, Nanjing 210023, People's Republic of China.
authors.forename: Le-yue
authors.initials: LY
authors.lastname: Du
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.forename: Da-wei
authors.initials: DW
authors.lastname: Qian
authors.forename: Shu
authors.initials: S
authors.lastname: Jiang
authors.forename: Er-xin
authors.initials: EX
authors.lastname: Shang
authors.forename: Jian-ming
authors.initials: JM
authors.lastname: Guo
authors.forename: Jin-ao
authors.initials: JA
authors.lastname: Duan
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid; D044948:Flavonols / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000382:microbiology*; D013058:Mass Spectrometry; D064307:Microbiota
chemical_list: D044948:Flavonols; C432511:isorhamnetin 3-O-glucoside