Determination of St. John's wort components in dietary supplements and functional foods by liquid chromatography.
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.
Ang
Catharina Y W
CY
U.S. Food and Drug Administration, National Center for Toxicological Research, Division of Chemistry, Jefferson, AR 72079, USA. cang@nctr.fda.gov
Cui
Yanyan
Y
Chang
Hebron C
HC
Luo
Wenhong
W
Heinze
Thomas M
TM
Lin
Lawrence J
LJ
Mattia
Antonia
A
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
D007202:Indicators and Reagents; D012996:Solutions