title: Determination of St. John's wort components in dietary supplements and functional foods by liquid chromatography.
abstract: St. John's wort (Hypericum perforatum L.) preparations, a top-selling botanical dietary supplement used primarily as an antidepressant, has recently been used as an ingredient in some food products sold as functional foods. A rapid extraction technique followed by a liquid chromatographic (LC) method was developed to determine 4 characteristic bioactive compounds (pseudohypericin, hypericin, hyperforin, and adhyperforin) from St. John's wort in dietary supplements and functional foods to which it was added. Solid samples, including dried leaf/flower mixture, dietary supplement capsules, tea bags, puff and snack bar, were extracted with methanol by sonication. Noncarbonated, fruit-flavored drinks were centrifuged and mixed with methanol. Compounds were then determined by isocratic, reversed-phase LC with UV detection at 2 wavelengths and further identified or confirmed by photodiode array spectra and LC/mass spectrometry. Within-laboratory method variations (% RSD) were satisfactory. Very low amounts, if any, of the 4 components were found in drink and puff samples, and none was found in the snack bar. The methods developed provide a useful means for the determination of St. John's wort components in dietary supplements and functional foods.
authors.affiliation: U.S. Food and Drug Administration, National Center for Toxicological Research, Division of Chemistry, Jefferson, AR 72079, USA. cang@nctr.fda.gov
authors.forename: Catharina Y W
authors.initials: CY
authors.lastname: Ang
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Cui
authors.forename: Hebron C
authors.initials: HC
authors.lastname: Chang
authors.forename: Wenhong
authors.initials: W
authors.lastname: Luo
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Heinze
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Lin
authors.forename: Antonia
authors.initials: A
authors.lastname: Mattia
mesh_terms: D000465:Algorithms; D001628:Beverages / Q000032:analysis; D002138:Calibration; D002853:Chromatography, Liquid; D019587:Dietary Supplements / Q000032:analysis*; D035264:Flowers / Q000737:chemistry; D020902:Hypericum / Q000737:chemistry*; D007202:Indicators and Reagents; D018515:Plant Leaves / Q000737:chemistry; D012015:Reference Standards; D012996:Solutions
chemical_list: D007202:Indicators and Reagents; D012996:Solutions