Ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry for determination of avicularin metabolites produced by a human intestinal bacterium

• Published in: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences Analytical technologies in the biomedical and life sciences, 2014-02, Vol.949-950, p.30-36
• Main Authors: Zhao, Min, Xu, Jun, Qian, Dawei, Guo, Jianming, Jiang, Shu, Shang, Er-xin, Duan, Jin-ao, Yang, Jing, Du, Le-yue
• Format: Article
• Language: English
• Subjects: 16S rRNA; Avicularin; Bacillus; Bacillus - isolation & purification; Bacillus - metabolism; Bacillus sp. 46; Bacteria; Chromatography, High Pressure Liquid - methods; Feces - microbiology; Flavonoids - analysis; Flavonoids - metabolism; Human; Humans; Liquid chromatography; Mass spectrometry; Metabolism; Metabolites; Microbiota; Strain; Tandem Mass Spectrometry - methods; UPLC/Q-TOF-MS
• ISSN: 1570-0232; 1873-376X
• DOI: 10.1016/j.jchromb.2014.01.005

•A human intestinal bacterium could metabolize avicularin.•UPLC/Q-TOF-MS was used for identification of avicularin metabolites.•Bacillus sp. 46 was identified by 16S rRNA gene sequencing.•Bacillus sp. 46 could metabolize avicularin to quercetin and quercetin glycosides. Intestinal bacteria from human were screened to isolate the specific bacteria involved in the metabolism of avicularin. A Gram-positive anaerobic bacterium, strain 46, capable of metabolizing avicularin (quercetin-3-O-arabinoside) was isolated for the first time. Its 16S rRNA gene sequence showed 99% similarity with that of Bacillus. Then strain 46 was identified as a species of the genus Bacillus, and was named to be Bacillus sp. 46. Additionally, the metabolites were analyzed by ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS) technique combined with Metabolynx™ software. The structure of these metabolites were proposed and confirmed by comparing the UPLC retention time and MS/MS spectrum with that of authentic standards. Parent compound and six metabolites were detected in the isolated bacterial samples compared with blank samples. Avicularin (M1) was anaerobic metabolized to its aglycone quercetin (M2) and methoxylated avicularin (M3, M4), then quercetin was converted to quercetin glycosides: quercetin-3-O-rhamnoside (M5), quercetin-3-O-glucoside (M6) and quercetin-7-O-glucoside (M7) by Bacillus sp. 46. The metabolic pathway and metabolites of avicularin by the intestinal bacterium Bacillus sp. 46 were reported for the first time.