Chemical Fingerprinting and Quantitative Determination of P57 in Hoodia Species and Dietary Supplements Claiming to Contain H. gordonii by UPLC-PDA/MS

Abstract

Hoodia gordonii, Family Asclepiadaceae, is a succulent plant and is traditionally used in South Africa for its appetite suppressant properties [1]. A UPLC method with UV/MS detection for analysis of eleven oxypregnane glycosides and P57 from Hoodia species has been developed. Chromatographic separation and quantitative determination of P57 in Hoodia species were accomplished on a C18 column using a gradient mobile phase of water and acetonitrile, both containing 0.05% formic acid. Flow rate, detection wavelength and temperature were adjusted to 0.35 mL/min, 220 nm and 40°C, respectively. The limits of detection by LC-MS method was found to be 1 ng/mL and by LC-UV method to be 0.3 µg/mL. LC-mass spectrometry coupled with electrospray ionization (ESI) interface method is described for the identification of P57 in various plant samples. This method involved the use of the [M+Na]+ ions of P57 in the positive ion mode with selective ion monitoring (SIM). The developed method was validated for P57 and successfully applied to the identification of twelve oxypregnane glycosides in four different species of Hoodia, 23 related genera and thirty-five (35) dietary supplements which claim to contain H. gordonii. The UPLC profiles of various plant samples were compared for the presence of oxypregnane glycosides. All four species of Hoodia and nine (9) dietary supplements were found to contain P57. Different sample matrixes were successfully analyzed, providing the wide range of applicability of this method, including the analyses of gels, capsules, tablets, sprays, tea bags, snack bars, powders and juices. Acknowledgements: This research is funded in part by “Science Based Authentication of Dietary Supplements” funded by the Food and Drug Administration grant number 2 U01 FD 002071-07.