title: Development of a simple HPLC method for determination of paeoniflorin-metabolizing activity of intestinal bacteria in rat feces.
abstract: A simple and reproducible HPLC method for the determination of paeoniflorin (PF)-metabolizing activity of intestinal bacteria in rat feces was developed and validated. Orally administered PF, a major active constituent of Paeoniae Radix, is metabolized into a bioactive compound, paeonimetabolin I (PM-I) by intestinal bacteria. Direct determination of the PF-metabolizing rate into PM-I is hard to achieve by HPLC due to the lack of intense chromophore in PM-I. However, when PF was incubated with Lactobacillus brevis, an intestinal bacterium, in the presence of phenylmercaptan, the metabolizing rate of PF into 8-phenylthio-paeonimetabolin I (PT-PM-I) was found to be equivalent to that of PF into PM-I. Thus, the PF-metabolizing activity of intestinal bacteria in rat feces was determined by measuring the rate of biotransformation of PF into PT-PM-I, which was detected by HPLC at 255 nm. This method can be utilized in the biopharmaceutical study of traditional Chinese formulations containing Paeoniae Radix.
authors.affiliation: Institute of Natural Medicine, Toyama Medical and Pharmaceutical University, Japan.
authors.forename: Ju-Xiu
authors.initials: JX
authors.lastname: He
authors.forename: Teruaki
authors.initials: T
authors.lastname: Akao
authors.forename: Tadato
authors.initials: T
authors.lastname: Tani
mesh_terms: D000818:Animals; D001419:Bacteria / Q000378:metabolism*; D001565:Benzoates / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics; D001711:Biotransformation; D001952:Bridged-Ring Compounds / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003720:Densitometry; D005243:Feces / Q000382:microbiology*; D005960:Glucosides / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics; D007422:Intestines / Q000382:microbiology*; D007778:Lactobacillus / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D039821:Monoterpenes; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet; D006027:Glycosides
chemical_list: D001565:Benzoates; D001952:Bridged-Ring Compounds; D005960:Glucosides; D039821:Monoterpenes; C015423:peoniflorin; D006027:Glycosides; C106915:paeonimetabolin I