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Torras-Claveria L.,University of Barcelona | Berkov S.,Agrobioinstitute Dragan Tzankov Blvd. | Codina C.,University of Barcelona | Viladomat F.,University of Barcelona | Bastida J.,University of Barcelona
Industrial Crops and Products | Year: 2014

One hundred and six ornamental varieties of Narcissus were analysed by GC-MS in an attempt to determine their alkaloid profile and the relationships between them were explored by multivariate statistical methods. Leaf and bulb tissues were analysed separately. A total of 61 Amaryllidaceae alkaloids and 2 protoalkaloids were identified and quantified. Different alkaloid profiles were found in leaves and bulbs, with leaves showing a higher quantity and more complex profile of alkaloids. Important differences were also found among plant varieties. k-Means cluster analysis determined five clusters based on similarities in alkaloid composition in both leaves and bulbs. The predominant alkaloids were lycorine-type in leaves, and galanthamine-type in bulbs. A correspondence analysis suggested that a global relationship between horticultural divisions of ornamental Narcissus varieties and k-means clusters based on alkaloid composition was unlikely, although some clusters were found to be particularly associated with certain divisions. © 2014 Elsevier B.V.

Berkov S.,University of Barcelona | Berkov S.,Agrobioinstitute Dragan Tzankov Blvd. | Bastida J.,University of Barcelona | Viladomat F.,University of Barcelona | Codina C.,University of Barcelona
Talanta | Year: 2011

Galanthamine, an acetylcholinesterase inhibitor marketed as a hydrobromide salt for the treatment of Alzheimer's disease, is obtained from some Amaryllidaceae plants. A new method was developed and validated for its quantification by GC-MS in different plant sources: bulbs and leaves from Narcissus confusus; bulbs from N. pseudonarcissus cv. Carlton; and leaves and in vitro cultures from L. aestivum. Samples (50 mg) were extracted with methanol (1 mL) for 2 h, then aliquots of the extracts were silylated and analyzed by GC-MS. The calibration line was linear over a range of 15-800 μg galanthamine/sample, ensuring an analysis of samples with a content of 0.03-1.54% analyte referred to dry weight. The recovery was generally more than 95%. Good inter- and intra assay precision was observed (RSD < 3%). Principal component analysis of GC-MS chromatograms allowed discrimination of the plant raw material with respect to species, organs and geographical regions. The analytical method developed in this study proved to be simple, sensitive and far more informative than the routine analytical methods (GC, HPLC, CE and NMR), so it may be useful for quality control of plant raw materials in the pharmaceutical industry. © 2010 Elsevier B.V. All rights reserved.

Berkov S.,University of Barcelona | Berkov S.,Agrobioinstitute Dragan Tzankov Blvd. | Viladomat F.,University of Barcelona | Codina C.,University of Barcelona | And 3 more authors.
Journal of Mass Spectrometry | Year: 2012

Galanthamine-type alkaloids produced by plants of the Amaryllidaceae family are potent acetylcholinesterase inhibitors. One of them, galanthamine, has been marketed as a hydrobromide salt for the treatment of Alzheimer's disease. In the present work, gas chromatography with electron impact mass spectrometry (GC-EIMS) fragmentation of 12 reference compounds isolated from various amaryllidaceous plants and identified by spectroscopic methods (1D and 2D nuclear magnetic resonance, circular dichroism, high-resolution MS (HRMS) and EIMS) was studied by tandem mass spectrometry (GC-MS/MS) and accurate mass measurements (GC-HRMS). The studied compounds showed good peak shape and efficient GC separation with a GC-MS fragmentation pattern similar to that obtained by direct insertion probe. With the exception of galanthamine-N-oxide and N-formylnorgalanthamine, the galanthamine-type compounds showed abundant [M]+. and [M-H]+ ions. A typical fragmentation pattern was also observed, depending on the substituents of the skeleton. Based on the fragmentation pathways of reference compounds, three other galanthamine-type alkaloids, including 3-O-(2′-butenoyl)sanguinine, which possesses a previously unelucidated structure, were identified in Leucojum aestivum ssp. pulchelum, a species endemic to the Balearic islands. GC-MS can be successfully applied to Amaryllidaceae plant samples in the routine screening for potentially new or known bioactive molecules, chemotaxonomy, biodiversity and identification of impurities in pharmaceutical substances. Copyright © 2012 John Wiley & Sons, Ltd.

Stoykova P.,Agrobioinstitute Dragan Tzankov Blvd. | Stoeva-Popova P.,Winthrop University
Plant Cell, Tissue and Organ Culture | Year: 2011

Due to the rising public concern over the use of genes conferring antibiotic and herbicide resistance, alternative systems for selection after plant transformation are being developed. A positive selection system consists of a physiologically inert metabolite as the selection agent and a respective gene which determines a metabolic advantage via selection agent utilization. The transformed cells are able to overcome the suppressive effects of the selection, while the untransformed ones starve but are not killed. The enzyme phosphomannose isomerase (PMI, E. C. 5.3. 1.8) catalyzes the reversible interconversion of mannose-6-phosphate and fructose-6-phosphate in prokaryotic and eukaryotic organisms. The PMI selection system is called positive due to the effect of "starvation" caused to the nontransformed plant tissue because of its incapability to utilize mannose as a carbon source. In this mini-review we researched the literature to obtain a more detailed view of the characteristics, specifics, problems, and advantages of applying the PMI/mannose selection system. © 2010 Springer Science+Business Media B.V.

Berkov S.,University of Barcelona | Berkov S.,Agrobioinstitute Dragan Tzankov Blvd. | Bastida J.,University of Barcelona | Sidjimova B.,Bulgarian Academy of Science | And 2 more authors.
Chemistry and Biodiversity | Year: 2011

Seventy alkaloids of galanthamine, lycorine, homolycorine, tazettine, haemanthamine, narciclasine, and tyramine types were detected by GC/MS in 25 Galanthus elwesii and seven Galanthus nivalis populations, collected from different locations in Bulgaria. Intraspecies diversity in the alkaloid profiles regarding the main alkaloid types (chemotypes) was observed. Tyramine-type protoalkaloids (namely, hordenine and its derivatives) were dominant in 19 populations of G. elwesii. In other populations of G. elwesii, the plants accumulated mainly homolycorine-, lycorine-, and galanthamine-type alkaloids. The alkaloid profiles of G. nivalis were dominated by narciclasine-, galanthamine-, lycorine-, haemanthamine-, or tazettine-type compounds. Geographical distribution of chemotypes indicated a relationship between populations, since adjacent populations often displayed similar alkaloid profiles. The results from year-to-year sampling and transplantation experiments imply genetic determination of alkaloid synthesis in the two studied species of Galanthus. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich.

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