ABSTRACT
A water-free, ternary solvent mixture consisting of a natural deep eutectic solvent (NADES), ethanol, and triacetin was investigated concerning its ability to dissolve and extract curcumin from Curcuma longa L. To this purpose, 11 NADES based on choline chloride, acetylcholine, and proline were screened using UV-vis measurements. A ternary phase diagram with a particularly promising NADES, based on choline chloride and levulinic acid was recorded and the solubility domains of the monophasic region were examined and correlated with the system's structuring via light scattering experiments. At the optimum composition, close to the critical point, the solubility of curcumin could be enhanced by a factor of >1.5 with respect to acetone. In extraction experiments, conducted at the points of highest solubility and evaluated via HPLC, a total yield of ~84% curcuminoids per rhizome could be reached. Through multiple extraction cycles, reusing the extraction solvent, an enrichment of curcuminoids could be achieved while altering the solution. When counteracting the solvent change, even higher concentrated extracts can be obtained.
Subject(s)
Curcuma/chemistry , Curcumin/chemistry , Curcumin/isolation & purification , Ethanol/chemistry , Triacetin/chemistry , Acetylcholine/chemistry , Choline/chemistry , Proline/chemistry , SolubilityABSTRACT
A choline chloride + lactic acid (1:1) natural deep eutectic solvent (NADES) is used as an adjuvant to ethanol/triacetin mixtures to solubilize and extract curcumin from Curcuma Longa. The obtained NADES/ethanol/triacetin mixtures are homogeneous, transparent and of low viscosity even in the absence of water. Dynamic light scattering revealed significant nanostructures, typical of surfactant-free microemulsions. A twofold increase of curcumin solubility and remarkable extraction power (yield of ~90%) can be achieved in the ternary system including the NADES, although curcumin is hydrophobic and the used NADES are very polar. Due to the elevated solubility of curcumin, more extraction cycles can be made than in the previously published aqueous systems with the same amount of solution. As a result, less solvent is required to achieve the same extraction yield.
Subject(s)
Curcuma/chemistry , Curcumin/chemistry , Plant Extracts/chemistry , Dynamic Light Scattering , Hydrophobic and Hydrophilic Interactions , Solubility , Solvents/chemistry , Surface-Active Agents/chemistry , ViscosityABSTRACT
Fatty acid composition of dietary fat is one of the detrimental factors in colon cancer development. Fats containing omega 6-polyunsaturated fatty acids (e.g. corn oil) enhance and omega 3-polyunsaturated fatty acids (e.g. fish oil) reduce chemically-induced colon cancer in animal studies. The purpose of this study is to investigate the effects of dietary mustard oil (containing omega 3-polyunsaturated fatty acid) on azoxymethane-induced colon cancer in rats and compare with corn and fish oil treated groups. Colon tumor incidence and multiplicity were found to be 90, 75, and 50% and 1.7, 0.8, and 0.4 tumors/rat in corn, fish and mustard oil treated groups respectively. Omega-3 polyunsaturated fatty acid levels were highest in serum and colon microsomal fractions of the fish oil group followed by the mustard oil group. Corn oil group had the highest level of omega 6-polyunsaturated fatty acid levels in serum and colon microsomal fractions. The results indicate that dietary mustard oil is more effective in preventing colon cancer in rats than dietary fish oil.
