Optimization of extraction for diterpenoids from Euphorbia fischeriana Steud using response surface methodology and structure identification by UPLC-Q-TOF-MS.

Jolkinolide A, jolkinolide B, 17-hydroxyjolkinolide A and 17-hydroxyjolkinolide B are abundant constitutes in Euphorbia Fischeriana Steud and exhibit profound bioactivities. In this study, they were selected as quality control to optimize the extraction of E. fischeriana. Response surface methodology employing Box-Behnken design was applied to test the optimal conditions for the extraction. The optimized conditions for the simultaneous extraction of four diterpenoids from E. fischeriana were: ethanol concentration 100%, extraction temperature 74 °C and extraction time 2.0 h. The extraction contents for jolkinolide A, jolkinolide B, 17-hydroxyjolkinolide A and 17-hydroxyjolkinolide B were 0.1763, 0.9643, 0.4245 and 2.8189 mg/g. The extract obtained under the optimal conditions was injected into UPLC-Q-TOF-MS system. Fifty-one peaks were identified. Two peaks were tentatively identified as new compounds. The compounds were diterpenoids, fatty oil, phenolics and others.