Iridoid and phenylethanoid glycosides were used as compounds to monitor the quality of Devil’s Claw (Harpagophytum procumbens) based products in this investigation. A HPLC-DAD method was developed for the determination of the phenylethanoid glycoside isoacteoside and the iridoid glycoside harpagoside in commercially available Devil’s Claw products. The limits of detection (LOD) obtained were 1.08 μg/ml for harpagoside and 1.70 μg/ml for
isoacteoside. Limits of quantification (LOQ) of harpagoside and isoacteoside were 3.59 μg/ml and 5.65 μg/ml respectively. The harpagoside and isoacteoside contents in the ethanol extracts of the commercial products were found to be in the range of 2.2 % - 3.9 % and 0.22 % - 0.50 % respectively. 

Keywords: Harpagophytum procumbens, phenylethanoid glycosides, iridoid glycosides, harpagoside, HPLC-DAD profiles