Recovery of phorbol esters from pressed jatropha seeds by surfactant extraction and cloud-point separation

Phorbol esters (PEs) are effective bio-pesticides and potentially applied in lymphocyte disease treatment. Generally, PEs can be extracted from pressed Jatropha curcas L. seeds (PJS) using methanol; however, this approach has safety and health concerns. Thus, surfactants were introduced as alternative solvents for extraction and recovery processes. The extraction conditions were optimized by a central composite rotatable design (CCRD). Nonionic surfactants had higher PE extraction efficiencies than anionic surfactants. The optimal extraction conditions consisted of 9.4% Dehydol LS12, 51.4 min of extraction time at 1:10 g mL−1, and agitation at 1000 rpm, which resulted in an 84% PEs extraction efficiency and 90% of the crude protein remaining in the residual. For PE recovery, cloud-point separation was selected to concentrate the PEs in the nonionic surfactant-rich phase with 5.9% (w/v) Na2SO4. A total of 91.4% of the PEs in the surfactant-rich phase were separated from the solution and analyzed by HPLC-UV.