DETERMINATION OF HARPAGIDE, 8-PARA-COUMAROYL HARPAGIDE, AND HARPAGOSIDE BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY IN HARPAGOPHYTUM-PROCUMBENS DRUGS AND IN A COMMERCIAL EXTRACT

A selective method for the determination of HARPAGIDE (HG), 8-para-coumaroyl HARPAGIDE (8PCHG) and HARPAGOSIDE (HS) is described. HS and 8PCHG are the two main compounds extracted from commercial dry extract of Harpagophytum secondary roots. Analysis of iridoids was performed using a linear gradient system of methanol/water as mobile phase, on RP 18 column. For HG Light-Scattering and UV detection were used for the quantification. Assays were linear in the concentration ranges studied. Statistic evaluation of the method was also realised to improve its security. In a total run time of 60 mn this procedure permitted to quantify simultaneously these three iridoids in the drug including HG for the first time in HPLC.