Alkaloids of (Kunth) J.F. Macbr. and Meerow (Amaryllidaceae) from Ecuador and its cholinesterase-inhibitory activity.

Alzheimer's disease is considered the most common cause of dementia and, in an increasingly aging population worldwide, the quest for treatment is a priority. Amaryllidaceae alkaloids are of main interest because of their cholinesterase inhibition potential, which is the main palliative treatment available for this disease. We evaluated the alkaloidal profile and the inhibitory activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) of bulb alkaloid extract of and collected in Ecuador. Using gas chromatography coupled to mass spectrometry (GC-MS), we identified typical Amaryllidaceae alkaloids in these species, highlighting the presence of lycorine-type alkaloids in and haemanthamine/crinine-type in . The species and showed inhibitory activities against AChE (IC values of 25.48 ± 0.39 and 3.45 ± 0.29 μg.mL, respectively) and BuChE (IC values of 114.96 ± 4.94 and 58.89 ± 0.55 μg.mL, respectively). Computational experiments allowed us to understand the interactions of the alkaloids identified in these samples toward the active sites of AChE and BuChE. , some alkaloids detected in these Amaryllidaceae species presented higher estimated binding free energy toward BuChE than galanthamine. This is the first study about the alkaloid profile and biological potential of species.