Alkaloid profile in Pyrolirion albicans Herb. (Amaryllidaceae), a Peruvian endemic species

The Amaryllidaceae family is widely distributed in different regions of the neotropics and temperate areas of the world. Species of the subfamily Amaryllidoideae are unique in producing the alkaloid galanthamine, which inhibits the action of acetylcholinesterase and is used for the treatment of Alzheimer's disease. In Perú, 15 genera and 68 species belonging to the Amaryllidoideae have been reported in different types of forest, ranging from wet montane to dry, as well as the sandy biomes of the Pacific coastal region, with the greatest diversity in the south. In the tribe Eustephieae, the Andean genus Pyrolirion Herb has eight species, six of which are endemic to Peru. In this work, the leaves and bulbs of Pyrolirion albicans were analyzed for their alkaloid content for the first time, using gas chromatography (GC) coupled to mass spectrometry (MS). The alkaloids determined in the leaves were galanthamine, chlidanthine, tazettine and lycorine and those in the bulbs were galanthamine, N-demethylgalanthamine, vittatine/crinine, montanine, pancracine, sternbergine, lycorine and hippeastrine. Owing to their important bioactive properties, the high quantity of montanine and galanthamine determined in the bulbs is of particular interest. Keywords Amaryllidaceae alkaloids, GC-MS, Galanthamine, Montanine, Pyrolirion albicans, Endemis

QToF exact mass and ESI fragmentation of bioactive Amaryllidaceae alkaloids

Amaryllidaceae alkaloids are a particular group of alkaloids exclusive to the Amarylloideae subfamily. Important from a biological and pharmacological point of view, they have antiparasitic, antiviral and antitumoral activities. Notably, galanthamine has been approved by the FDA as an acetylcholinesterase inhibitory drug for the treatment of Alzheimer's disease. Overall, Amaryllidaceae alkaloids are easy to analyse by GC–MS, but some are difficult to differentiate or detect. In the current study, some of these problems were resolved by applying an alternative analytical technique, high resolution ESI-MS/MS, a soft ionisation method producing different fragmentation patterns. Amongst the Amaryllidaceae alkaloids, only galanthamine has been previously analysed by high resolution ESI-MS/MS. In this work, a large number of Amaryllidaceae alkaloids were studied by high resolution ESI-MS/MS, providing important new structural information

Research in natural products: Amaryllidaceae ornamental plants as sources of bioactive compounds

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Revised NMR data for Incartine: an alkaloid from Galanthus elwesii

Phytochemical studies on Galanthus elwesii resulted in the isolation of five alkaloids: incartine, hordenine, hippeastrine, 8-O-demethylhomolycorine and lycorine. The NMR data given previously for incartine were revised and completed by two-dimensional 1H-1H and 1H-13C chemical shift correlation experiments. In vitro studies on the bioactivity of incartine were carried out

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

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

Cholinesterase Inhibition Activity, Alkaloid Profiling and Molecular Docking of Chilean Rhodophiala (Amaryllidaceae)

Amaryllidaceae plants are the commercial source of galanthamine, an alkaloid approved for the clinical treatment of Alzheimer's disease. The chemistry and bioactivity of Chilean representatives of Rhodophiala genus from the family of Amaryllidaceae have not been widely studied so far. Ten collections of five different Chilean Rhodophiala were analyzed in vitro for activity against enzymes such as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) as well as for their alkaloid composition by GC-MS. To obtain an insight into the potential AChE and BuChE inhibitory activity of the alkaloids identified in the most active samples, docking experiments were carried out. Although galanthamine was found neither in aerial parts nor in bulbs of R. splendens, these plant materials were the most active inhibitors of AChE (IC50: 5.78 and 3.62 μg/mL, respectively) and BuChE (IC50: 16.26 and 14.37 μg/mL, respectively). Some 37 known alkaloids and 40 still unidentified compounds were detected in the samples, suggesting high potential in the Chilean Amaryllidaceae plants as sources of both novel bioactive agents and new alkaloids. Keywords: AChE; BuChE; GC-MS; Rhodophiala; alkaloids; molecular docking

Alkaloid Profiling and Cholinesterase Inhibitory Potential of Crinum × amabile Donn. (Amaryllidaceae) Collected in Ecuador

Natural products are one of the main sources for developing new drugs. The alkaloids obtained from the plant family Amaryllidaceae have interesting structures and biological activities, such as acetylcholinesterase inhibition potential, which is one of the mechanisms used for the palliative treatment of Alzheimer's disease symptoms. Herein we report the alkaloidal profile of bulbs and leaves extracts of Crinum × amabile collected in Ecuador and their in vitro inhibitory activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes. Using Gas Chromatography coupled to Mass Spectrometry (GC-MS), we identified 12 Amaryllidaceae alkaloids out of 19 compounds detected in this species. The extracts from bulbs and leaves showed great inhibitory activity against AChE and BuChE, highlighting the potential of Amaryllidaceae family in the search of bioactive molecules. Keywords: Amaryllidaceae alkaloids, Crinum × amabile, AChE, BuChE, GC-M

Structural Diversity and Biological Potential of Alkaloids from the Genus Hippeastrum, Amaryllidaceae: an Update

The subfamily Amaryllidoideae, Amaryllidaceae, presents an exclusive group of structures known as Amaryllidaceae alkaloids, which have a broad spectrum of biological activities. These plants are classified into 59 genera, including Hippeastrum Herb., which comprises approximately 60 species distributed mainly in South America, being widely used as ornamental plants due to the beauty of its flowers. This review presents an update about the alkaloid profiling of Hippeastrum extracts published between 2012 and 2021, as well as an approach to the biological potential of these compounds. Supplementary information: The online version contains supplementary material available at 10.1007/s43450-021-00211-z. Keywords: Alzheimer's disease; Anti-inflammatory; Antiparasitic; Antitumoral; Cytotoxic; Isoquinoline alkaloids