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Vermaak, I., Hamman, J.H., Viljoen A.M. 2010. High performance thin layer chromatography as a method to authenticate Hoodia gordonii raw material and products. South African Journal of Botany 76: 119-124.

Hoodia gordonii which contains the perceived active molecule, P57, is a plant used in many weight loss products that are highly susceptible to adulteration due to increased public demand and limited availability.  Rapid and simple methods for authentication and confirmation of the presence of P57 are desirable for the quality control of H. gordonii raw material and products.  High performance thin layer chromatography (HPTLC) analysis of several H. gordonii raw material samples collected from different locations as well as weight loss products was carried out on silica gel plates and developed in a mobile phase of toluene:chloroform:ethanol (40:40:12.5 v/v/v).  Liebermann-Burchard (LB) reagent was used as derivatising agent since it is specific for glycosides and triterpenes (such as P57) and the plates were viewed under UV light at 365 nm.  This method produced good separation of the compounds in complex mixtures with well-defined bands including that of the P57 band (Rf 0.42), which was confirmed by liquid chromatography coupled to mass spectrometry (LC-MS) after preparative thin layer chromatography (TLC).  All the HPTLC results obtained for the H. gordonii raw materials and products were confirmed with quantitative LC-MS analyses, which confirmed the qualitative reliability of the HPTLC method.  The HPTLC method was used successfully to develop a chemical fingerprint for authentication and reliable confirmation of the presence of P57 in H. gordonii raw material and products. 

Hoodia gordonii | Apocynaceae | cross section of stem | botanical - Botha Ave, Cresta, Gauteng, South Africa [2009 ©]