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

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,L7a 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 (4.6 mm × 150 mm i.d.,5 μm) with an isocratic elution with a mobile phase consisting of water and acetonitrile at a flow rate of 0.25 mL/min at column temperature of 30 ℃ and UV detection was set at 272 nm.An ESI source was used with a positive ionization mode.The calibration curve was linear in the ranges of 9.9-79 μg/mL for Euphorbia factor L1,3.8-30.5 μg/mL for Euphorbia factor L2,and 1.0-20.6 μg/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 0.286 mg/g,respectively,which decreased more sharply than those in unprocessed E.lathyris seeds which were 4.915,1.944 and 0.425 mg/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.