Separation and purification of curcumin using novel aqueous two-phase micellar systems composed of amphiphilic copolymer and cholinium ionic liquids

• Published in: Separation and purification technology 2020-11, Vol.250, p.117262, Article 117262
• Main Authors: Kurnik, Isabelle S., Noronha, Mariana A., Câmara, Mayra C.C., Mazzola, Priscila G., Vicente, António A., Pereira, Jorge F.B., Lopes, André M.
• Format: Article
• Language: English
• Subjects: aqueous two-phase micellar systems (ATPMS); curcumin (CCM); ionic liquids (ILs); Pluronic F68; polymeric micelles (PMs); Science & Technology; separation
• ISSN: 1383-5866; 1873-3794; 1383-5866
• DOI: 10.1016/j.seppur.2020.117262

[Display omitted] •Partition of curcumin (CCM) using ATPMS composed of Pluronic F68 + ILs was studied.•Cholinium ILs decreased the phase separation temperature of Pluronic F68/buffer.•The phase separation decreased with the increase of the IL anion hydrophobicity.•CCM was preferentially partitioned into polymeric micelles (PMs)-rich phase.•ILs-based ATPMS were very selective to recover CCM from crude extract of C. longa L. Novel aqueous two-phase micellar systems (ATPMS) composed of Pluronic F68, a triblock amphiphilic copolymer, and cholinium-based ionic liquids (ILs) were formulated and applied for separation/purification of curcumin (CCM). CCM stability in the presence of ATPMS components was also evaluated. CCM is stable up to 24 h in copolymer (1.0 – 10.0 wt%) and ILs (0.1 – 3.0 M) aqueous solutions. Very mild phase separation conditions (close to room temperature) were achieved by adding cholinium ILs to the Pluronic F68 + McIlvaine buffer at pH 6.0 solution. The decrease of cloud-point temperature is dependent on the relative hydrophobicity of IL anion, [Hex]− > [But]− > [Pro]− > [Ac]− > Cl−. ATPMS composed of more hydrophobic ILs ([Ch][Hex] > [Ch][But] > [Ch][Pro]) are most efficient in the partition of commercial CCM into polymeric micelles (PMs)-rich phase. The best ATPMS (0.70 M [Ch][But] and 0.60 M [Ch][Hex]-based ATPMS) were then used to purify CCM from a crude extract of Curcuma longa L. Both systems were very selective to separate CCM from protein-based contaminants (selectivity values ≥ 25; purification yields ≥ 12-fold). Pluronic F68-based ATPMS are promising for selective separation of hydrophobic biomolecules by using cholinium-based ILs as adjuvants to adjust phase separation temperatures and biomolecules’ partition.