Improved extraction of the natural anticancerigen pristimerin from Mortonia greggii root bark using green solvents and aqueous two-phase systems

Two green and sustainable strategies for pristimerin recovery from Mortonia greggii (Celastraceae) root bark were assayed using ionic liquids and ethanol-phosphate biphasic systems. The yields of pristimerin extraction with ionic liquids (1-ethyl-3-methylimidazolium acetate (EMIMAc) and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4)) were lower than those obtained through a traditional solvent extraction method. Even more, the implantation of a BMIMBF4-phosphate Aqueous Two-Phase System (ATPS) did not improve the pristimerin recovery yield. Therefore, extractions in ATPS using mixtures of ethanol and phosphate salts considering as factors the extraction time and the number of extraction steps were performed. The obtained extract on the ethanol-rich phase showed a comparable pristimerin yield (7.16 ± 0.09 mg/g) and twice the purity (12.82 ± 0.42 mg/g) to that obtained in traditional solvent extraction (30 min) with a shorter (15 min) extraction time. The proposed methodology represents a feasible, scalable and environmentally-friendly procedure to obtain sufficient amounts of this natural anticarcinogenic compound for in vivo bioactivity assays.