Extraction of Curcuminoids and Carvacrol with Biobased Ionic Liquids—Evaluation of Anti-Cancer Properties of Curcuminoid Extracts

Six biobased ionic liquids were prepared from saturated fatty acids (octanoic, decanoic and dodecanoic acids) and choline with yields up to 90% following procedures respecting green chemistry principles. These ionic liquids were fully characterized (NMR, IR, elemental analysis, viscosimetry and TGA) and used as extraction solvents for bioactive compounds (curcuminoids and carvacrol) using classical conditions, and the ionic liquids were able to be recovered after five runs without loss of activity. The ionic liquid containing a C12 carbon chain was the best extracting solvent, extracting 95% of the total curcuminoids contained in turmeric and 69% of the total carvacrol contained in oregano, which are higher yields compared to the extraction procedures described in the literature. As C12 ionic liquids were more cytotoxic than C8 ones, the biological activity of the curcuminoids extracted with C8 ionic liquids was evaluated on a MIAPaCa-2, a pancreatic adenocarcinoma cell line for which antitumor activity of curcuminoids had previously been reported. Compared to the cytotoxicity of the commercially available extract, the cytotoxic activity of the extracts was slightly weaker.