Estudio acerca de la presencia de alcaloides en especies de la flora de Cataluña

[spa] El presente trabajo pretende enmarcarse en el espíritu de estudio sistemático de la flora con relación a la presencia de alcaloides. Hemos elegido los alcaloides para limitarnos a un tipo concreto de productos naturales y por ser uno de los grupos de principios activos de mayor variedad y potencial farmacológica. Se ha adoptada para ello un criterio de selección ("screening"), respecto a la presencia o ausencia de alcaloides como paso previo para realizar con posterioridad estudios más profundos con las especies que consideremos alcaloidicas. Hemos aplicado este criterio a una serie limitada de especies vegetales, recogidas al azar en distintas comarcas de Cataluña. La búsqueda de plantas alcaloidicas constituye un área de trabajo reciente en nuestro laboratorio, y éste es uno de los trabajos iniciales de la nueva línea, lo que representa enfrentarse con una serie de problemas típicos de la falta de experiencia en un determinado tipo de trabajo. La resolución de estos problemas iniciales facilitará la realización de posteriores trabajos. En un futuro pretendemos ampliar progresivamente el espectro de especies examinadas, así como profundizar simultáneamente en el estudio de las especies positivas hasta el nivel que nuestros medios nos permitan, intentando en lo posible la colaboración de expertos en diferentes especialidades

Evolució històrica de l'ús dels alcaloides com agents terapèutics

Les relacions de l'home amb el medi vegetal, en aquest cas amb finalitats curatives, té una llarga història i forces perspectives de futu

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

Podeu consultar el llibre complet a: http://hdl.handle.net/2445/12071

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

Potencial biotecnològic del cultiu de cèl·lules vegetals per a l'obtenció de productes farmacèutics

Plants produce a peculiar group of natural products, particular to the plant kingdom, the secondary metabolites, which are very numerous and structurally diverse. Provided that plant cells can grow 'in vitro', their culture offers the possibility of producing some of these compounds of pharmaceutical interest in large quantities. Alkaloids, steroids, cardiotonic glycosides, quinones and terpens, for example. are produced by either cell suspension cultures or immobilized cells; sometimes at a higher rate than in the whole plant. These systems are also used to yield several substances by means of a given biotransformation reaction which cannot be achieved in any other way. The use of cell cultures in pharmaceutical industry is just one of the many sides of plant biotechnology, which is proving to become an indispensable technique soon in the future

Plant sources of galanthamine: phytochemical and biotechnological aspects.

Galanthamine, an Amaryllidaceae type alkaloid, is an AChE inhibitor marketed as a hydrobromide salt for the treatment of Alzheimer's disease, poliomyelitis and other neurological diseases. Although the chemical synthesis of galanthamine has been successfully performed, plants are the main source of its production. The phytochemical and biotechnological aspects of plants currently used for galanthamine production, namely Leucojum aestivum, Narcissus ssp. Ungernia victoris and Lycoris radiata, are summarized in the present paper

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

Alkaloid constituents of the Amaryllidaceae plant Amaryllis belladonna L.

The plant family Amaryllidaceae is well-known for its unique alkaloid constituents, which exhibit a wide range of biological activities. Its representative, Amaryllis belladonna, has a geographical distribution covering mainly southern Africa, where it has significant usage in the traditional medicine of the native people. In this study, A. belladonna samples collected in Brazil were examined for alkaloid content. Alkaloid profiles of A. belladonna bulbs were generated by a combination of chromatographic, spectroscopic and spectrometric methods, including GC-MS and 2D NMR. In vitro screening against four different parasitic protozoa (Trypanosoma cruzi, T. brucei rhodesiense, Leishmania donovani and Plasmodium falciparum) was carried out using the A. belladonna crude methanol extract, as well as three of its alkaloid isolates. Twenty-six different Amaryllidaceae alkaloids were identified in the A. belladonna bulb samples, and three of them were isolated. Evidence for their respective biosynthetic pathways was afforded via their mass-spectral fragmentation data. Improved data for 1-O-acetylcaranine was provided by 2D NMR experiments, together with new 1H-NMR data for buphanamine. The crude extract and 3-O-acetylhamayne exhibited good antiprotozoal activity in vitro, although both with a high cytotoxic index