Abstract
Abstract
The isolation of a compound from a natural source involves many organic and mostly toxic solvents for extraction and purification. Natural deep eutectic solvents have been shown to be
efficient options for the extraction of natural products. They have the advantage of being composed of abundantly available common primary metabolites, being nontoxic and environmentally
safe solvents. The aim of this study was to develop a natural deep eutectic solvent-based extraction method for galanthamine, an important therapeutic agent for the treatment of Alzheimerʼs
disease. This alkaloid can be produced by synthesis or by extraction from
Narcissus
bulbs. To develop an efficient extraction method, a number of different natural deep eutectic
solvents was first tested for their solubilization capacity of galanthamine bromide salt. Promising results were obtained for ionic liquids, as well as some amphoteric and acidic natural
deep eutectic solvents. In a two-cycle extraction process, the best solvents were tested for the extraction of galanthamine from bulbs. The ionic liquids produced poor yields, and the best
results were obtained with some acid and sugar mixtures, among which malic acid-sucrose-water (1 : 1 : 5) proved to be the best, showing similar yields to that of the exhaustive Soxhlet
extraction with methanol. Furthermore, the natural deep eutectic solvent was more selective for galanthamine.