HPLC-DAD analysis of 15 monoterpene glycosides in oil peony seed cakes sourced from different cultivation areas in China

The oil peony seed cake, one of the most important by-products during the seed oil preparation, contains numerous monoterpene glycosides. The development and optimization of a simple and reproducible method for simultaneous qualitative and quantitative determination of monoterpene glycosides from oil peony seed cakes would be a valuable work for its further utilization. In this study, an HPLC method using DAD detector was developed to analyse fifteen monoterpene glycosides in oil peony seed cakes. The optimum resolution of the fifteen monoterpene glycosides was achieved on an ODS-AQ column. Acetonitrile (solvent A) and 0.5% potassium dihydrogen phosphate solution (pH 2.8) (solvent B) were used as the mobile phase by a gradient elution. Paeoniflorin showed the highest content amongst 15 monoterpene glycosides. It accounted for more than half of the total content of the fifteen monoterpene glycosides (TCFMG) in oil peony seed cake, followed by oxypaeonifiorin and albiflorin. The samples of different cultivation areas contain the different contents of monoterpene glycosides, mainly determined by their geographical variation. The higher level contents of monoterpene glycoside are believed to have more potential in medicinal application. The method thus could be used to control the quality of products from oil peony seed cakes.