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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N-oxide alkaloids from Crinum amabile (Amaryllidaceae)

Natural products play an important role in the development of new drugs. In this context, the Amaryllidaceae alkaloids have attracted considerable attention in view of their unique structural features and various biological activities. In this study, twenty-three alkaloids were identified from Crinum amabile by GC-MS and two new structures (augustine N-oxide and buphanisine N-oxide) were structurally elucidated by NMR. Anti-parasitic and cholinesterase (AChE and BuChE) inhibitory activities of six alkaloids isolated from this species, including the two new compounds, are described herein. None of the alkaloids isolated from C. amabile gave better results than the reference drugs, so it was possible to conclude that the N-oxide group does not increase their therapeutic potential

Amaryllidaceae alkaloids with anti-Trypanosoma cruzi activity

Background: Chagas disease, caused by the protozoan Trypanosoma cruzi, is a neglected disease that afects ~7 million people worldwide. Development of new drugs to treat the infection remains a priority since those currently available have frequent side efects and limited efcacy at the chronic stage. Natural products provide a pool of diver sity structures to lead the chemical synthesis of novel molecules for this purpose. Herein we analyzed the anti-T. cruzi activity of nine alkaloids derived from plants of the family Amaryllidaceae. Methods: The activity of each alkaloid was assessed by means of an anti-T. cruzi phenotypic assay. We further evalu ated the compounds that inhibited parasite growth on two distinct cytotoxicity assays to discard those that were toxic to host cells and assure parasite selectivity. Results: We identifed a single compound (hippeastrine) that was selectively active against the parasite yielding selectivity indexes of 12.7 and 35.2 against Vero and HepG2 cells, respectively. Moreover, it showed specifc activity against the amastigote stage (IC50=3.31 μM). Conclusions: Results reported here suggest that natural products are an interesting source of new compounds for the development of drugs against Chagas disease. Keywords: Chagas disease, Trypanosoma cruzi, Alkaloids, Amaryllidaceae, Hippeastrine, Phenotypic assays, Cytotoxicit

N-oxide alkaloids from Crinum amabile (Amaryllidaceae)

Natural products play an important role in the development of new drugs. In this context, the Amaryllidaceae alkaloids have attracted considerable attention in view of their unique structural features and various biological activities. In this study, twenty-three alkaloids were identified from Crinum amabile by GC-MS and two new structures (augustine N-oxide and buphanisine N-oxide) were structurally elucidated by NMR. Anti-parasitic and cholinesterase (AChE and BuChE) inhibitory activities of six alkaloids isolated from this species, including the two new compounds, are described herein. None of the alkaloids isolated from C. amabile gave better results than the reference drugs, so it was possible to conclude that the N-oxide group does not increase their therapeutic potential

Chemical and biological aspects of different species of the genus Clinanthus Herb. (Amaryllidaceae) from South America

The genus Clinanthus Herb. is found in the Andes Region (South America), mainly in Peru, Ecuador, and Bolivia. These plants belong to the Amaryllidaceae family, specifically the Amaryllidoideae subfamily, which presents an exclusive group of alkaloids known as Amaryllidaceae alkaloids that show important structural diversity and pharmacological properties. It is possible to find some publications in the literature regarding the botanical aspects of Clinanthus species, although there is little information available about their chemical and biological activities. The aim of this work was to obtain the alkaloid profile and the anti-cholinesterase activity of four different samples of Clinanthus collected in South America: Clinanthus sp., Clinanthus incarnatus, and Clinanthus variegatus. The alkaloid extract of each sample was analyzed by gas chromatography coupled with mass spectrometry (GC-MS), and their potential against the enzymes acetyl- and butyrylcholinesterase were evaluated. Thirteen alkaloids have been identified among these species, while six unidentified structures have also been detected in these plants. The alkaloid extract of the C. variegatus samples showed the highest structural diversity as well as the best activity against AChE, which was likely due to the presence of the alkaloid sanguinine. The results suggest this genus as a possible interesting new source of Amaryllidaceae alkaloids, which could contribute to the development of new medicines. Keywords: Alzheimer’s disease; Amaryllidaceae alkaloids; Clinanthus incarnatus; Clinanthus sp.; Clinanthus variegatus; alkaloid profiling

The Anti-Cholinesterase Potential of Fifteen Different Species of Narcissus L. (Amaryllidaceae) Collected in Spain

Narcissus L. is a renowned plant genus with a notable center of diversity and is primarily located in the Mediterranean region. These plants are widely recognized for their ornamental value, owing to the beauty of their flowers; nonetheless, they also hold pharmacological importance. In Europe, pharmaceutical companies usually use the bulbs of Narcissus pseudonarcissus cv. Carlton to extract galanthamine, which is one of the few medications approved by the FDA for the palliative treatment of mild-to-moderate symptoms of Alzheimer’s disease. The purpose of this study was to evaluate the potential of these plants in Alzheimer’s disease. The alkaloid extract from the leaves of different species of Narcissus was obtained by an acid-base extraction work-up -procedure. The biological potential of the samples was carried out by evaluating their ability to inhibit the enzymes acetyl- and butyrylcholinesterase (AChE and BuChE, respectively). The species N. jacetanus exhibited the best inhibition values against AChE, with IC50 values of 0.75 ± 0.03 µg·mL−1, while N. jonquilla was the most active against BuChE, with IC50 values of 11.72 ± 1.15 µg·mL−1.Programa Iberoamericano de Ciencia y Tecnologia para el Desarrollo (CYTED, 223RT0140)

N-oxide alkaloids from Crinum amabile (Amaryllidaceae)

Natural products play an important role in the development of new drugs. In this context, the Amaryllidaceae alkaloids have attracted considerable attention in view of their unique structural features and various biological activities. In this study, twenty-three alkaloids were identified from; Crinum amabile; by GC-MS and two new structures (augustine; N; -oxide and buphanisine; N; -oxide) were structurally elucidated by NMR. Anti-parasitic and cholinesterase (AChE and BuChE) inhibitory activities of six alkaloids isolated from this species, including the two new compounds, are described herein. None of the alkaloids isolated from; C. amabile; gave better results than the reference drugs, so it was possible to conclude that the; N; -oxide group does not increase their therapeutic potential

The brazilian Amaryllidaceae as a source of acetylcholinesterase inhibitory alkaloids

Nine Brazilian Amaryllidaceae species were studied for their alkaloid composition and acetylcholinesterase (AChE) inhibitory activity via GC-MS and a modified Ellman assay, respectively. A total of thirty-six alkaloids were identified in these plants, of which Hippeastrum papilio and H. glau-cescens exhibited the highest galanthamine content and the best IC50 values against AChE. Furthermore, Hippeastrum vittatum and Rhodophiala bifida also showed notable AChE inhibitory effects. X-ray crys-tallographic data for four galanthamine-type com-pounds revealed significant differences in the orientation of theN-methyl group, which are shown to be related to AChE inhibition