Sustainable Extraction of Alkaloids from Worsleya procera: Improving the Method with Green Chemistry

Green chemistry seeks to develop safer, more efficient, and environmentally sustainable processes, particularly for the extraction of bioactive compounds from natural sources. In this study, Worsleya procera, a chemically underexplored species of the Amaryllidaceae family, was investigated as a source of alkaloids with therapeutic potential. To the best of our knowledge, this work represents the first systematic comparison of multiple traditional and green extraction workflows applied to this species. Several protocols were evaluated using conventional solvents (methanol, hexane) and greener alternatives (ethanol, heptane), with or without modifications in the extraction steps. The optimized protocol reduced solvent use by ∼46.5% and simplified the workflow while maintaining extraction efficiency. A total of 27 alkaloids were detected, and 15 compounds belonging to the licorine, homolicorine, and tazettine subtypes were annotated. Bioaffinity chromatography revealed that extracts obtained with greener solvents showed selective inhibition of butyrylcholinesterase (76.9 ± 5.0%) compared to conventional methods (56.0 ± 6.3%), while acetylcholinesterase inhibition remained similar (26.3 ± 2.2% vs 25.7 ± 0.8%). Galantamine, used as a positive control, inhibited both enzymes by >97%, validating the bioassay. These findings demonstrate that greener extraction strategies not only reduce environmental impact but also preserve biological activity, positioning the proposed methodology as a sustainable alternative for natural product research.