Development and Application of an Extraction and Quantitative HPLC Method for Sulforaphene in Radish

Sulforaphene, an isothiocyanate generated by the conversion of glucoraphenin in radish (Raphanus sativus L.), plays an important role in plants as a defensive compound and has been shown to have anti-cancer properties. However, a reliable method for the determination of sulforaphene in radish has not yet been established. In the present study, the enzymolysis conditions, extraction solvent and extraction conditions employed to obtain sulforaphene from radish were all optimized using single factor experiments and orthogonal testing. During these trials, sulforaphene was separated and quantified using reverse phase C18 high performance liquid chromatography (HPLC), employing methanol:water (3:7 ν/ν) as the mobile phase at a flow rate of 0.3 mL · min−1 together with a detection wavelength of 245 nm. Evaluation of this newly established method showed good linearity between the sulforaphene concentration and the characteristic peak area over the range of 5 to 200 μg · mL−1 (R2 = 0.9996). This method was thus found to be precise. It was established that sulforaphene was extracted from radish with 95.48% efficiency (RSD = 0.94%) using the optimized conditions. This same technique was successfully applied to the quantification of sulforaphene in the fleshy roots of different radish germplasms as a means of selecting the germplasms with the highest sulforaphene levels.