Isolation and identification of the metabolites of paeonol in human urine.
Paeonol, a major component of Paeonia suffruticosa Andrews, is used in clinical situations in China as a natural anti-inflammatory agent. The aim of the present study is to investigate the metabolism of paeonol in humans.        Six metabolites were isolated from human urine after oral administration of paeonol, and their structures were elucidated as resacetophenone (M1), resacetophenone-2-O-sulfate (M2), 2-hydroxy-4-methoxyacetophenone-5-O-sulfate(M3), 2-hydroxy-4-methoxyacetophenone-5-O-glucopyranuronoside (M4), 2-hydroxyacetophenone-4-O-glucopyranuronoside (M5) and 2,5-dihydroxy-4-methoxyacetophenone(M6) by a series of analyses involving mass spectrometry, (1)H NMR, (13)C NMR and NOESY spectra.        In addition, three more metabolites 2,4-dihydroxyacetophenone-5-O-sulfate (M7), paeonol-2-O-glucopyranuronoside (M8) and paeonol-2-O-sulfate (M9), were identified in human urine by using a UPLC/Q-TOF-MS/MS method.        This is the first study of paeonol metabolism in humans. Based on the identified metabolites, possible metabolic pathways of paeonol in humans are proposed. Paeonol is metabolized mainly by hydroxylation and demethylation to give the corresponding phase I metabolites, M1, M6 and 2,4,5-trihydroxyacetophenone, and which then underwent conjugation with glucuronic acid or sulfuric acid to form phase II metabolites.
Department of Natural Products Chemistry, Shenyang Pharmaceutical University, Shenyang, People's Republic of China.
Liqin
L
Ding
Zhaoxi
Z
Liu
Feng
F
Zhao
Gang
G
Bai
Lixia
L
Chen
Xinsheng
X
Yao
Feng
F
Qiu
D000098:Acetophenones / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism / Q000652:urine*; D000328:Adult; D002851:Chromatography, High Pressure Liquid; D020719:Glucuronides / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D013058:Mass Spectrometry; D053858:Metabolic Networks and Pathways; D013431:Sulfates / Q000378:metabolism; D055815:Young Adult
D000098:Acetophenones; D020719:Glucuronides; D013431:Sulfates; C013638:paeonol