Planta Med 2015; 81 - PX50
DOI: 10.1055/s-0035-1556494

Recovery of metabolites from natural deep eutectic solvent matrices by countercurrent separation

Y Liu 1, J Garzon 1, JB Friesen 1, 2, DC Lankin 1, JB McAlpine 1, SN Chen 1, GF Pauli 1
  • 1UIC/NIH Center for Botanical Dietary Supplements Research, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, USA
  • 2Physical Sciences Department, Rosary College of Arts and Sciences, Dominican University, River Forest, Illinois 60305, USA

NAtural Deep Eutectic Solvents (NADES) were discovered in 2011 as being mixtures of polar “primary metabolites” that exhibit unexpected solubilizing and stabilizing abilities for hydrophobic and/or bioactive ingredients. However, due to the inherent low vapor pressure of NADES, it is challenging to recover analytes such as “secondary” metabolites from a NADES-analyte(s) matrix by conventional liquid chromatography. The present study shows that countercurrent separation (CCS) can perform this task successfully. The resolution capability of CCS depends on the differential distribution coefficients (K values) of the analytes. Compared to most bioactive constituents, the NADES components have extreme K values (close to 0 or ∞, in RP or NP, resp.) because of their high polarity. Glucose-choline chloride-water (2:5:5, mole/mole) with rutin, quercetin, kaempferol, or daidzein were chosen as the test matrices. The CCS fraction analysis by UV-UHPLC and qHNMR showed that CCS can recover the target analyte completely from the NADES-analyte matrix, and at the same time yield the NADES quantitatively, allowing further study of “primary” NADES vs. bioactive “secondary” metabolites in botanical extracts.

*represents equal contribution to this work