Analysis and determination of diterpenoids in unprocessed and processed Euphorbia lathyris seeds by HPLC–ESI-MS.

Abstract: Euphorbia lathyris (Caper spurge) is a toxic and potent Chinese materia medica (T/PCMM). This study sought a method for identifying five diterpenoids (Euphorbia factors L₁−L₃, L_7a and L₈) with the spectra of UV and mass, quantifying three diterpenoids L₁, L₂, and L₈ in crude extracts of unprocessed and processed E. lathyris seeds by liquid chromatography/electrospray ionization mass spectrometry (LC–ESI-MS). The analysis was achieved on an Agilent Eclipse XDB-C18 column (4.6mm×150mm i.d., 5μm) with an isocratic elution with a mobile phase consisting of water and acetonitrile at a flow rate of 0.25mL/min at column temperature of 30°C and UV detection was set at 272nm. An ESI source was used with a positive ionization mode. The calibration curve was linear in the ranges of 9.9–79μg/mL for Euphorbia factor L₁, 3.8–30.5μg/mL for Euphorbia factor L₂, and 1.0–20.6μg/mL for Euphorbia factor L₈. The average recoveries (n=6) of three diterpenoids were 98.39%, 91.10% and 96.94%, respectively, with RSD of 2.5%, 2.4% and 2.1%, respectively. The contents of the three diterpenoids in processed E. lathyris seeds were 3.435, 1.367 and 0.286mg/g, respectively, which decreased more sharply than those in unprocessed E. lathyris seeds which were 4.915, 1.944 and 0.425mg/g, respectively. The method is simple, accurate, reliable and reproducible, and it can be applied to control the quality of unprocessed and processed E. lathyris seeds. [Copyright &y& Elsevier]