Planta Med 2025; 91(08): 440-450
DOI: 10.1055/a-2563-7599
Original Papers

Recovery techniques for Hydroxynaphthoquinone Enantiomers of Alkanna tinctoria (L.) from Natural Deep Eutectic Solvents: A Comparative Analysis

Authors

  • Elodie Bossard

    Division of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
  • Nikolaos Tsafantakis

    Division of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
  • Nektarios Aligiannis

    Division of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
  • Ioanna Chinou

    Division of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
  • Nikolas Fokialakis

    Division of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece

This research was funded by the European Commission through the EU H2020-ITN-MICROMETABOLITE project (Grant No. 721635).

Abstract

A natural deep eutectic solvent (NaDES) composed of levulinic acid and glucose using a molar ratio of 5 : 1 (molHBA:molHBD) and 20% of water (w/w) (LeG_5_20) was found as a great alternative to the commonly used organic solvents for the extraction of hydroxynaphthoquinone enantiomers (HNQs) from Alkanna tinctoria (L.) Tausch roots. In the present work, a comparative investigation of recovery methods for HNQs, such as solid-phase extraction, macroporous resin, and water as an anti-solvent, was performed to face the main disadvantage of NaDES: the inability to be evaporated. The highest recovery of HNQs was recorded using the solid-phase extraction on a reversed-phase C8 cartridge with a total hydroxynaphthoquinone content (TNC) of 46.79 ± 0.952 mg/g of dry weight (DW). In addition, a great recovery of HNQs was also reported for the macroporous resin Amberlite XAD 4 with a TNC value of 37.21 ± 1.789 mg/g DW, while the precipitation of HNQs by using water as an anti-solvent (1 : 5, v/v) offered a TNC value of 28.68 ± 0.023 mg/g DW. The macroporous resin Amberlite XAD also showed a great potential for larger-scale applications. In fact, the developed scale-up process, involving Amberlite XAD 4, showed a great recovery efficiency for HNQs (34.126 ± 1.093 mg/g DW), an acceptable robustness (RSD < 15%), and the possibility of recycling LeG_5_20 with a recovery greater than 50%; therefore, it is an excellent green alternative extraction procedure for HNQs.



Publication History

Received: 11 January 2025

Accepted after revision: 20 March 2025

Accepted Manuscript online:
20 March 2025

Article published online:
17 April 2025

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