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Arpad Pusztai - One of the best experts on this subject based on the ideXlab platform.
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effect of diets containing genetically modified potatoes expressing Galanthus nivalis lectin on rat small intestine
The Lancet, 1999Co-Authors: Stanley W B Ewen, Arpad PusztaiAbstract:Summary Diets containing genetically modified (GM) potatoes expressing the lectin Galanthus nivalis agglutinin (GNA) had variable effects on different parts of the rat gastrointestinal tract. Some effects, such as the proliferation of the gastric mucosa, were mainly due to the expression of the GNA transgene. However, other parts of the construct or the genetic transformation (or both) could also have contributed to the overall biological effects of the GNA-GM potatoes, particularly on the small intestine and caecum.
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Effect of the insecticidal Galanthus nivalis agglutinin on metabolism and the activities of brush border enzymes in the rat small intestine
Journal of Nutritional Biochemistry, 1996Co-Authors: Arpad Pusztai, J. F. J. G. Koninkx, Henno G.c.j.m. Hendriks, Wouter Kok, Saskia Hulscher, Els J. M. Van Damme, Willy J. Peumans, George Grant, Susan BardoczAbstract:Abstract With increasing use of lectin genes in crop plants to improve insect resistance, the dietary exposure of humans to lectins will rise and it is necessary to assess whether the presently most favored insecticidal lectin, Galanthus nivalis agglutinin, would be harmful for mammals. Effects of Galanthus nivalis agglutinin on gut and brush border enzymes were studied in rats over a 10-day dietary exposure and compared with those of a known antinutrient, phytohaemagglutinin. At a level that provides insecticidal protection for plants but did not reduce the growth of young rats, Galanthus nivalis agglutinin had negligible effects on the weight and length of the small intestine even though there was a slight, but significant hypertrophy of this tissue. However, the activities of brush border enzymes were affected; sucrase-isomaltase activity was nearly halved and those of alkaline phosphatase and aminopeptidase were significantly increased. Although most of the changes in gut metabolism caused by the incorporation of Galanthus nivalis agglutinin in the diet were less extensive than those found with toxic phytohaemagglutinin, some of them may be potentially deleterious. Thus, further and longer animal studies are needed to establish whether it is safe to use Galanthus nivalis agglutinin in transgenic plants destined for human consumption.
Nehir Unver Somer - One of the best experts on this subject based on the ideXlab platform.
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Phytochemical constituents from Galanthus alpinus Sosn. var. alpinus and their anticholinesterase activities
South African Journal of Botany, 2019Co-Authors: Ceren Emir, Ahmet Emir, B Bozkurt, Nehir Unver SomerAbstract:Abstract Phytochemical studies on Galanthus alpinus Sosn. var. alpinus from Turkey resulted in the isolation of 11 metabolites including, 1 terpenoid; (+)-blumenol A 1, 2 lignans; pinoresinol 2 and epipinoresinol 3, and 8 other compounds; (+)-homolycorine 4, (+)-8-O-demethylhomolycorine 5, arolycoricidine 6, N-Trans-feruloyltyramine 7, (−)-lycorine 8, nicotinic acid 9, O-methylnorbelladine 10 and hordenine 11. To the best of our knowledge, all compounds are reported for the first time from the title species. The chemical structures of the compounds were elucidated by MS, 1D and 2D experiments. Also, isolated compounds were subjected to in vitro acetylcholinesterase and butyrylcholinesterase inhibitory activity assays.
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Alkaloid profiling of Galanthus woronowii Losinsk. by GC-MS and evaluation of its biological activity
Marmara Pharmaceutical Journal, 2017Co-Authors: B Bozkurt, Strahil Berkov, Gi Kaya, Mustafa Ali Onur, Jaume Bastida, Ahmet Emir, Nehir Unver SomerAbstract:The alkaloid profiles of the aerial parts and the bulbs of Galanthus woronowii Losinsk. were analyzed by means of Gas Chromatography-Mass Spectrometry (GC-MS). Totally, twentyeight compounds were detected. Galanthamine and galanthine were found to be the main alkaloids both in the extracts of the aerial parts and the bulbs. Most of the identified compounds were lycorine and galanthamine-type Amaryllidaceae alkaloids. In addition, the acetylcholinesterase (AChE) inhibitor potentials of the extracts prepared from the aerial parts and bulbs were determined by in vitro Ellman’s method and both of the extracts were found to exhibit significant activity (aerial parts: IC50= 0.027 μg/mL and bulbs: IC50= 0.084 μg/mL).
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Alkaloids from Galanthus fosteri
Phytochemistry Letters, 2016Co-Authors: Ahmet Emir, Mustafa Ali Onur, Jaume Bastida, B Bozkurt, Ceren Emir, Nehir Unver SomerAbstract:Abstract Three new alkaloids, oxoincartine, 3,11-O-diacetyl-9-O-demethylmaritidine and 11-O-acetyl-9-O-demethylmaritidine together with seven known compounds namely, incartine, galanthamine, galanthine, 9-O-methylpseudolycorine, N,O-dimethylnorbelladine, hordenine and vittatine were isolated from Galanthus fosteri Baker (Amaryllidaceae). Their structures were elucidated by spectroscopic analyses (UV, IR, MS, CD and 1D/2D NMR). Cholinesterase inhibitory activity potentials of the compounds were also determined.
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Phytochemical investigation of Galanthus woronowii
Biochemical Systematics and Ecology, 2013Co-Authors: Baran Sarikaya, Gi Kaya, Mustafa Ali Onur, Jaume Bastida, Nehir Unver SomerAbstract:• A new lycorine-type ( 5 ) alkaloid with nine known alkaloids were isolated from Galanthus woronowii (Amaryllidaceae).
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GC-MS investigation and acetylcholinesterase inhibitory activity of Galanthus rizehensis.
Zeitschrift für Naturforschung C, 2013Co-Authors: Baran Sarikaya, Gi Kaya, Mustafa Ali Onur, Nehir Unver Somer, Jaume Bastida, Strahil BerkovAbstract:GC-MS (gas chromatography-mass spectrometry) analyses of alkaloids in the aerial parts and bulbs of Galanthus rizehensis Stern (Amaryllidaceae), collected during two different vegetation periods, was performed. Twenty three alkaloids were identified in four different alkaloid extracts. Acetylcholinesterase (AChE) inhibitory activities of the alkaloid extracts were tested. Both the highest alkaloid diversity and the most potent inhibitory activity (IC50 12.94 microg/ml) were obtained in extracts from the bulbs of G. rizehensis collected during the fruiting period.
Mustafa Ali Onur - One of the best experts on this subject based on the ideXlab platform.
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Chemo-profiling of some Turkish Galanthus L. (Amaryllidaceae) species and their anticholinesterase activity
South African Journal of Botany, 2020Co-Authors: B Bozkurt, Gi Kaya, Mustafa Ali Onur, Nehir Unver-somerAbstract:Abstract Amaryllidaceae family, consisting of economically important plants with ornamental value, is very well-known for its isoquinoline alkaloids with variable biological activities and chemical structures. Among these alkaloids, an effective acetylcholinesterase inhibitor galanthamine, is prescribed widely in the treatment of Alzheimer's disease. Plants of the Amaryllidaceae family are therefore, subjected to intensive research to find potent cholinesterase inhibitors. The chemical composition of three Galanthus species including Galanthus krasnovii A.P. Khokhr., Galanthus gracilis Celak. and an endemic species Galanthus peshmenii A.P. Davis & C.D. Brickell were analyzed by GC–MS. In total, twenty-five alkaloids with various chemical structure types and a lignan, namely epipinoresinol were identified. Cholinesterase inhibitory potentials of the plant extracts were also determined by in vitro Ellman's method. Extracts of Galanthus krasnovii bulbs displayed the most promising acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities (AChE: IC50: 8.26 µg/mL and BuChE: IC50: 6.23 µg/mL).
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Alkaloid profiling, anticholinesterase activity and molecular modeling study of Galanthus elwesii
South African Journal of Botany, 2017Co-Authors: B Bozkurt, Gi Kaya, Mustafa Ali Onur, G. Coban, N. Unver-somerAbstract:Abstract In this study, Galanthus elwesii Hook. (Amaryllidaceae) was investigated for its chemical composition by using GC-MS (Gas Chromatography-Mass Spectrometry) method and anticholinesterase activity together with molecular modeling studies. Galanthus elwesii was collected from three different regions of Turkey and 44 compounds were detected by GC-MS in six different alkaloid extracts. The molecular docking technique was carried out to exhibit binding orientations of Galanthus elwesii compounds in the gorge of the active site of acetylcholinesterase (AChE) of Electrophorus electricus and equine butyrylcholinesterase (BuChE) constituted from the crystal structure of human BuChE with the help of homology modeling technique. Interesting results were obtained from the docking study, especially on O -methylleucotamine. The AChE and BuChE inhibitory activities of the extracts were also tested by in vitro Ellman method. The samples collected from Karaburun-Izmir were found to be the most active among others.
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Alkaloid profiling of Galanthus woronowii Losinsk. by GC-MS and evaluation of its biological activity
Marmara Pharmaceutical Journal, 2017Co-Authors: B Bozkurt, Strahil Berkov, Gi Kaya, Mustafa Ali Onur, Jaume Bastida, Ahmet Emir, Nehir Unver SomerAbstract:The alkaloid profiles of the aerial parts and the bulbs of Galanthus woronowii Losinsk. were analyzed by means of Gas Chromatography-Mass Spectrometry (GC-MS). Totally, twentyeight compounds were detected. Galanthamine and galanthine were found to be the main alkaloids both in the extracts of the aerial parts and the bulbs. Most of the identified compounds were lycorine and galanthamine-type Amaryllidaceae alkaloids. In addition, the acetylcholinesterase (AChE) inhibitor potentials of the extracts prepared from the aerial parts and bulbs were determined by in vitro Ellman’s method and both of the extracts were found to exhibit significant activity (aerial parts: IC50= 0.027 μg/mL and bulbs: IC50= 0.084 μg/mL).
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Alkaloids from Galanthus fosteri
Phytochemistry Letters, 2016Co-Authors: Ahmet Emir, Mustafa Ali Onur, Jaume Bastida, B Bozkurt, Ceren Emir, Nehir Unver SomerAbstract:Abstract Three new alkaloids, oxoincartine, 3,11-O-diacetyl-9-O-demethylmaritidine and 11-O-acetyl-9-O-demethylmaritidine together with seven known compounds namely, incartine, galanthamine, galanthine, 9-O-methylpseudolycorine, N,O-dimethylnorbelladine, hordenine and vittatine were isolated from Galanthus fosteri Baker (Amaryllidaceae). Their structures were elucidated by spectroscopic analyses (UV, IR, MS, CD and 1D/2D NMR). Cholinesterase inhibitory activity potentials of the compounds were also determined.
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GC/MS Analysis of Amaryllidaceae Alkaloids in Galanthus gracilis
Chemistry of Natural Compounds, 2014Co-Authors: B. Bozkurt-sarikaya, Strahil Berkov, Gi Kaya, Mustafa Ali Onur, Jaume Bastida, N. Unver-somerAbstract:structures, in the present study, we aimed to investigate the alkaloid composition of G. gracilis, collected from a different locality in Turkey, by GC/MS. In this study, the alkaloid extracts of Galanthus gracilis Celak. were examined by means of gas chromatography/mass spectrometry (GC/MS), and 20 alkaloids were reported. Homolycorine and 8-O-demethylhomolycorine are the main alkaloids in the extracts obtained from the aerial parts and bulbs, respectively. Additionally, the AChE inhibitory activity of the extracts prepared from the aerial parts and bulbs of G. gracilis was investigated by in vitro Ellmans method [10]. Potent inhibitory activity was recorded in the extracts of the bulbs and aerial parts of G. gracilis. To the best of our knowledge, this is the first report of a GC/MS study on the alkaloids of G. gracilis growing in Turkey. Based on the GC/MS analysis, a total of 20 alkaloids was detected in two different extracts prepared from G. gracilis (Table 1). The identified compounds possessed various Amaryllidaceae alkaloid skeleton types including phenanthridine, galanthamine, crinine, tazettine, lycorine, and homolycorine. Generally, homolycorine and tazettine type alkaloids were major components in the tested samples. Homolycorine was found to be the main alkaloid in the aerial part extract of G. gracilis (71.62%). Similarly, the extract obtained from the bulbs contained 8-O-demethylhomolycorine (44.39%), homolycorine (18.00%), and galanthindole (17.95%) in very high amounts. Tazettine was found to be present in both of the extracts (aerial parts, 18.41%; bulbs, 6.47%). Moreover, in the extracts of the bulbs, lycorine was detected (5.45%) and galanthamine was found in trace amounts. Due to the absence of related literature, GG-1 and GG-2 were not identified, but their mass fragmentation has specific properties for Amaryllidaceae alkaloids. AChE inhibitory activity potentials of the extracts were carried out using in vitro Ellmans method, and both of the extracts showed significant activity. The bulb extract of G. gracilis (IC 50 11.82 g/mL) was found to be more active than the extract of the aerial parts (IC 50 25.5 g/mL). Galanthamine was used as a positive control (IC 50 0.043 g/mL).
Nehir Unver - One of the best experts on this subject based on the ideXlab platform.
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New skeletons and new concepts in Amaryllidaceae alkaloids
Phytochemistry Reviews, 2007Co-Authors: Nehir UnverAbstract:The Amaryllidaceae alkaloids, represent a group of isoquinoline alkaloids, which are produced almost solely by members of the Amaryllidaceae family. The alkaloids of this family have attracted considerable amount of interest due to some important pharmacological activities they were shown to possess. In the last decade, our phytochemical studies on four Galanthus (Amaryllidaceae) species of Turkish origin have yielded quite a number of new alkaloids with diverse structures. Among these alkaloids, gracilines and plicamines constitute two new subgroups for the Amaryllidaceae alkaloids. The gracilines contain an incorporated 10b,4a-ethanoiminodibenzo[ b , d ]pyrane skeleton. The plicamines are dinitrogenous compounds, where the oxygen atom in position 7 of a tazettine skeleton is replaced by a nitrogen atom substituted by a pendant 4-hydroxyphenethyl moiety. One of the new alkaloids, galanthindole, which possesses a nonfused indole ring, unlike the already known subgroups of Amaryllidaceae alkaloids, may be considered as the prototype of a third new subgroup of the Amaryllidaceae alkaloids. Additionally, two known isoquinoline alkaloids which do not possess one of the established skeletons of the Amaryllidaceae alkaloids, namely ( − )-capnoidine and (+)-bulbocapnine, have been isolated from a Turkish Galanthus species. Totally, 21 new, 20 known alkaloids and 2 known lignans have been characterized. In this review, the isolation and structure elucidation of these compounds with interesting chemical structures are described.
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An Unusual Pentacyclic Dinitrogenous Alkaloid from Galanthus gracilis
Turkish Journal of Chemistry, 2005Co-Authors: Nehir Unver, G. Irem KayaAbstract:A minor alkaloid, namely gracilamine, was isolated from Galanthus gracilis. This was the first example of a pentacyclic dinitrogenous alkaloid isolated from a member of Amaryllidaceae. The structure of this alkaloid was elucidated by means of comprehensive spectroscopic methods (1D and 2D NMR, MS, UV, IR).
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Galanthindole: a new indole alkaloid from Galanthus plicatus ssp. byzantinus.
Planta Medica, 2003Co-Authors: Nehir Unver, G. Irem Kaya, Christa Werner, Robert Verpoorte, Belkis GözlerAbstract:A new indole alkaloid, galanthindole, was isolated from Galanthus plicatus ssp. byzantinus (Amaryllidaceae), a plant native to northwestern Turkey. Incorporating a non-fused indole ring, galanthindole may represent the prototype of a new subgroup of the Amaryllidaceae alkaloids. Two other bases, (+)-11-hydroxyvittatine and hordenine, are also reported from the same plant.
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Three New Tazettine-Type Alkaloids from Galanthus gracilis and Galanthus plicatus Subsp. byzantinus.
Planta Medica, 1999Co-Authors: Nehir Unver, Mustafa Ali Onur, Seda Noyan, Tekant Gözler, Belkis Gözler, Manfred HesseAbstract:Three new tazettine-type alkaloids were isolated from two different Galanthus species of Turkish origin. (+)-Isotazettinol and (+)-3-O-demethylmacronine are obtained from G. gracilis, while (+)-3- O-demethyl-3-epimacronine is found in G. plicatus subsp. byzantinus. The known base, trispheridine, is reported for the first time in Galanthus genus.
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Two novel dinitrogenous alkaloids from Galanthus plicatus subsp. byzantinus (Amaryllidaceae)
Phytochemistry, 1999Co-Authors: Nehir Unver, Tekant Gözler, Belkis Gözler, Nadja Walch, Manfred HesseAbstract:Abstract The minor alkaloids, (+)-plicamine and (−)-secoplicamine, from Galanthus plicatus subsp. byzantinus are the first examples of dinitrogenous alkaloids where the oxygen atom in position 7 of the basic tazettine molecule has been replaced by a nitrogen atom substituted by a pendant 4-hydroxyphenethyl moiety.
Aaron P. Davis - One of the best experts on this subject based on the ideXlab platform.
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Galanthus bursanus (Amaryllidaceae): a new species of snowdrop from the Marmara Sea region, NW Turkey
Kew Bulletin, 2019Co-Authors: Dimitri A. Zubov, Yıldiz Konca, Aaron P. DavisAbstract:Galanthus bursanus (Amaryllidaceae), a new snowdrop species endemic to the Marmara Sea region (Bursa Province, NW Turkey), is described and illustrated. Morphological differences between the new species and other possibly related Galanthus taxa ( G. plicatus subsp. byzantinus , G. ×valentinei nothosubsp. subplicatus , and G. reginae-olgae subsp. reginae - olgae ) are discussed. Photographs (habitat and morphology), a distribution map and a preliminary conservation assessment are provided.
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Snowdrops falling slowly into place: an improved phylogeny for Galanthus (Amaryllidaceae).
Molecular Phylogenetics and Evolution, 2013Co-Authors: Nina Rønsted, Dimitri Zubov, Sam Bruun-lund, Aaron P. DavisAbstract:Abstract Snowdrops ( Galanthus , 20 spp.; Amaryllidaceae) are cherished garden plants and the world’s most traded wild-sourced ornamental bulb genus. Despite their popularity and economic importance, species delimitation is problematic and the infrageneric classification uncertain. We present a molecular phylogenetic study of Galanthus with the aim of resolving these issues and to better understand the evolution within the genus. Sequences of nuclear encoded nrITS, and plastid encoded matK , trnLF , ndhF , and psbK–psbI , for all currently recognised species and two naturally occurring putative hybrids, were analysed using maximum parsimony and Bayesian inference. Phylogenetic analysis of Galanthus , based on nuclear ITS sequences, provides a well-resolved topology, including seven well-supported named clades (platyphyllus, trojanus, ikariae, elwesii, nivalis, woronowii, and alpinus), and five major clades (A–E). The recovered ITS topology is in accordance with the geographical distribution of Galanthus species. The combined plastid data set provided far less resolution than that of ITS, with generally lower levels of statistical support, and one case of significant incongruence with the ITS dataset (involving G. gracilis ). Phylogenetic network and hybridization analyses identified several possible hybridization events but these are more likely to be due to the result of a lack of resolution in the plastid dataset. The putative natural hybrid, G. × valentinei nothosubsp. subplicatus , is supported by our data and analyses, whereas a hybrid origin for G. ×allenii is not. ITS and plastid data indicated that some Galanthus species are in need of taxonomic recircumscription.
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Galanthus panjutinii sp. nov. : a new name for an invalidly published species of Galanthus (Amaryllidaceae) from the northern Colchis area of Western Transcaucasia
Phytotaxa, 2012Co-Authors: Dimitri A. Zubov, Aaron P. DavisAbstract:Galanthus panjutinii , a new species endemic to the calcareous ridges of the northern Colchis area (Western Transcaucasia) is described and illustrated. Morphological differences between the new species and the closely related species, G. krasnovii and G. platyphyllus , are discussed. A line illustration, photographs, map and conservation assessment are provided.
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phylogenetic analysis of leucojum and Galanthus amaryllidaceae based on plastid matk and nuclear ribosomal spacer its dna sequences and morphology
Plant Systematics and Evolution, 2004Co-Authors: Ma D Lledo, Aaron P. Davis, Manuel B Crespo, Mark W ChaseAbstract:Phylogenetic analyses of the monocotyledonous genera Leucojum and Galanthus (Amaryllidaceae, Asparagales), using plastid (trnL-F and matK) and largely non-coding nuclear ribosomal (ITS) DNA sequences show the two to be closely related to Lapiedra, Narcissus, Vagaria, Pancratium and Sternbergia. We compare the results obtained with a combined parsimony analysis of these nucleotide sequences with that of a matrix of morphological characters. The sampling included all species of Leucojum and most species of Galanthus (representing all series and subseries of the genus) and used as outgroup the above mentioned genera of Amaryllidaceae shown to be close relatives. The plastid, nuclear and morphological data were analysed independently and in combination, showing that the boundaries between the two genera are not appropriate. Galanthus is monophyletic but embedded in Leucojum. On the basis of chromosome numbers and floral characters Leucojum has been previously divided into four subgenera, which have been accepted as genera by some authors. In our phylogenetic analyses (separate as well as combined), Leucojum species are separated in two primary clades corresponding to L. subgenera Ruminia + Acis and L. Leucojum + Aerosperma. The taxonomic implications of this pattern are discussed, and an alternative classification is proposed. Finally, biogeographic relationships of species of both Leucojum and Galanthus are discussed, emphasising the possible origin of the narrowly distributed taxa of Leucojum relative to the widespread species.
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The systematic value of nuclear DNA content in Galanthus
Plant Systematics and Evolution, 2003Co-Authors: B. J. M. Zonneveld, J. M. Grimshaw, Aaron P. DavisAbstract:Genome size (Cx-value) was applied as a new criterion to investigate the relationships within the genus Galanthus L. (Amaryllidaceae). More than 150 samples representing all species, from wild and cultivated material, were investigated. Most species of Galanthus have the same basic chromosome number (2n=2x=24). However, the somatic nuclear DNA contents (2C), as measured by flow cytometry with propidium iodide was shown to range from 48.6 to 90.4 pg for the diploids. This implies that the largest genome contains roughly 4 × 1010 more base pairs than the smallest and has chromosomes that are nearly twice as large. On this basis we assumed that nuclear DNA content as measured using flow cytometry may be used to produce easily obtainable systematic data. Triploidy in G. rizehensis and G. alpinus var. bortkewitschianus, tetraploidy in G. elwesii and hexaploidy in G. lagodechianus were confirmed by flow cytometry. In addition, as well as a number of polyploid cultivars, triploids were also found in G. nivalis and tetraploids and hexaploids in G. transcaucasicus and G. elwesii, respectively. DNA content confirmed the close relationships in some species pairs, including: G. nivalis and G. reginae-olgae, G. krasnovii and G. platyphyllus, G. gracilis and G. elwesii. Further investigation of the taxonomic status of these pairs is suggested. As a rapid diagnostic tool, applicable even in the case of dormant bulbs or sterile plants, flow cytometry has applications for conservation and in particular the monitoring of the trade in bulbous plants.
