Supercritical extraction of main alkaloids from Galanthus elwesii

Supercritical fluid extraction (SFE) can be used for a wide range of chemical components, including alkaloids. Using pure CO₂ is not sufficient for the extraction of polar components, adding a small amount of polar modifier increases the effectiveness of the method [1]. In this study, the effect of carbon-dioxide density with the use of methanol as modifier, basic plant material treatment and temperature were evaluated from Galanthus elwesii L., an ornamental member of the Amaryllidaceae family. Galanthamine is used in the treatment of Alzheimer's disease as an inhibitor of acetyl-cholinesterase, while lycorine's antitumor activity has been demonstrated both in vivo and in vitro [2].

Quantitative determination of alkaloids was performed by HPLC. Samples were taken at temperatures 40 °C, 50 °C and 60 °C, pressures of 100 bar, 200 bar and 300 bar were used with methanol modifier (Jasco Laboratory SFE system). The highest quantity of galanthamine was obtained at 40 °C, 100 bar, the highest quantity of lycorine was found at 60 °C, 300 bar. Galanthamine: lycorine ratio changes at 60 °C, 300 bar. At low CO₂ density the extraction ratio of galanthamine is higher than at high density where the yield does not differ from each other compared to the density value change. For galanthamine, the best extraction value is at low, for lycorine at high density.

References:

[1] Rachmaniah O, Choi YH, Arruabarrena I, Vermeulen B, van Spronsen J, Verpoorte R, Witkamp, GJ. Environmentally benign supercritical CO₂ extraction of galanthamine from floricultural crop waste of Narcissus pseudonarcissus. J Supercrit Fluid 2014; 93: 7 – 19

[2] Bastida J, Berkov S, Torras L, Pigni NB, De Andrade JP, Martinez V, Codina C, Viladomat F. Chemical and biological aspects of Amaryllidaceae alkaloids. In: Munoz-Torrero D, editor. Recent Advances in Pharmaceutical Sciences 2011; 65 – 100