Alkaloid Composition and Biological Activities of the Amaryllidaceae Species Ismene amancaes (Ker Gawl.) Herb

Abstract

Natural products have always played a significant role in the search for new drugs. One of the most relevant alkaloid-containing plant groups is the Amaryllidaceae family, a source of exclusive structures with a wide variety of pharmacological activities. The aim of this work was to determine the alkaloid composition and biological potential of an extract from the bulbs of an endemic Peruvian Amaryllidaceae species Ismene amancaes (Ker Gawl.) Herb. The alkaloid profiling was carried out by GC-MS, which revealed the presence of 13 compounds, 2 of them unidentified. The plant extract was found to contain high amounts of lycoramine, a galanthamine-type alkaloid. The extract also presented low inhibitory potential against the enzymes AChE and BuChE, with IC₅₀ values of 14.6 ± 0.6 and 37.6 ± 1.4 μg·mL^-1, respectively, and good to moderate inhibitory activity against the protozoan Plasmodium falciparum strain FCR-3 (chloroquine-resistant), with IC₅₀ values of 3.78 ± 0.3 μg·mL^-1. This is the first report of the alkaloid profile of a plant of the Ismene genus, which could be an interesting source of bioactive compounds.

Keywords: Alzheimer’s disease; Amaryllidaceae; Ismene amancaes; Plasmodium falciparum; alkaloids; malaria.

Figure 1

Amaryllidaceae alkaloids identified in Ismene amancaes bulbs by GC-MS.

Figure 2

AChE and BuChE inhibitory activity of Ismene amancaes. Sample: alkaloid extract of I. amancaes bulbs; Gal: galanthamine (reference compound).

Figure 3

In vitro antiplasmodial activity of the alkaloid extract from bulbs of Ismene amancaes.