Biomedical subjects

Jaume Bastida

Publications and source records attributed to Jaume Bastida.

24 records · Page 2Linked to original sources

PubMed2002

Acetylcholinesterase inhibitory activity of some Amaryllidaceae alkaloids and Narcissus extracts.

Amaryllidaceous plants produce pharmacologically active alkaloids, galanthamine being the most interesting for its use in the treatment of Alzheimer's disease as a cholinesterase inhibitor. The aim of this work was to test 23 pure Amaryllidaceae alkaloids and 26 extracts from different species of the genus Narcissus for their acetylcholinesterase inhibitory activity using galanthamine as a reference. Only seven alkaloids, belonging to the galanthamine and lycorine skeleton types, exhibited such an effect, sanguinine being the most active, even more than galanthamine. All the extracts with the highest acetylcholinesterase inhibitory activity contained galanthamine except that of N. assoanus, a lycorine type alkaloid-bearing species.

Alkaloids↗

PubMed2002

Biodiversity of mannose-specific lectins within Narcissus species.

Mannose-specific lectins (MSLs) were isolated from the bulbs of 27 species of wild Spanish Narcissi and compared to the commercially available MSL from daffodil (Narcissus pseudonarcissus, NPA). Molecular weight analysis showed the monomers of all the MSLs were at, or around, 12.5 kD. Haemagglutination assays showed that the MSLs exhibited activities at up to four times greater than that displayed by NPA and other MSLs derived from other species such as Galanthus nivalus (snowdrop) and Allium ursinum (ramson). Elution profiles from ion exchange chromatography exhibited similarities for species within the same taxonomic section suggesting that this method could aid in species classification. Further analysis by isoelectric focusing showed many isolectins are present in vivo and that even within a single peak from ion exchange chromatography there are numerous isolectins present. The basis of the isolectin heterogeneity is suggested to reside in the tetraploidy (sometime triploidy) nature of Narcissus genes.

Chromatography, Ion Exchange↗

PubMed2002

Alkaloids from Narcissus angustifolius subsp. transcarpathicus (Amaryllidaceae).

Seven alkaloids have been isolated from fresh bulbs of Narcissus angustifolius subsp. transcarpathicus (Amaryllidaceae). Nangustine, reported here for the first time, is the first 5,11-methanomorphanthridine alkaloid with a C-3/C-4 substitution. The structure and stereochemistry of this new alkaloid, as well as those previously known, have been determined by physical and spectroscopic methods. Spectroscopic data of pancracine have been completed. The in vitro assay activity against the parasitic protozoa Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani and Plasmodium falciparum was carried out with the compounds nangustine and pancracine.

Alkaloids↗

PubMed2002

A dinitrogenous alkaloid from Cyrtanthus obliquus.

The ethanolic extract of bulbs of Cyrtanthus obliquus (L.f.) Ait yielded the new dinitrogenous alkaloid obliquine (1), 3S, 4aS, 11S, 10bS-3,4,4a,13,11,5,6-heptahydro-5[2-(4-hydroxyphenyl)ethyl]-3-methoxy-13-methyl-[1,3-dioxolo[4,5-g]indolo[3,3a-c]-isoquinolin-12-one, together with the five known structures 11alpha-hydroxygalanthamine, 3-epimacronine, narcissidine, tazettine and trisphaeridine. All structures were established using 1D and 2D NMR techniques and HREIMS. The alkaloids were tested for cytotoxicity against two mammalian cell lines and did not show activity at concentrations up to 100 microg/ml.

Alkaloids↗

PubMedDate not supplied

Solid-phase extraction and reversed-phase high-performance liquid chromatography of the five major alkaloids in Narcissus confusus.

A novel, fast and precise method, combining solid-phase extraction and reversed-phase high-performance liquid chromatography is described for the quantitative determination of five alkaloids (galanthamine, N-formylnorgalanthamine, haemanthamine, homolycorine and tazettine/pretazettine) from bulbs of wild Narcissus confusus, a high galanthamine-containing plant species growing in the Iberian Peninsula.

Alkaloids↗

PubMedDate not supplied

Supercritical carbon dioxide extraction of colchicine and related alkaloids from seeds of Colchicum autumnale L.

A method for the extraction of the alkaloids colchicine, 3-demethylcolchicine and colchicoside from seeds of Colchicum autumnale by supercritical carbon dioxide has been established. Several parameters such as pressure, temperature, percentage of modifier and extraction time have been examined. Two extraction steps with constant carbon dioxide density (0.90 g/mL) and flux (1.5 mL/min) were required to extract the alkaloids in 110 min using 3% methanol as modifier. The quantitative determination of the alkaloids was performed by HPLC; the percentages of recovery were higher than 98% for the three alkaloids. This extraction procedure was compared with a conventional method involving maceration and sonication, and the same levels of alkaloids were obtained in each case. The supercritical carbon dioxide method is, however, very efficient, more rapid and more environmentally friendly than conventional methods.

Alkaloids↗