Antiprotozoal alkaloids from Galanthus trojanus

Two new alkaloid N-oxides, 1-O-acetyldihydromethylpseudolycorine N-oxide, and 11-hydroxyvittatine N-oxide, ten known alkaloids; arolycoricidine, haemanthamine, O-methylnorbelladine, narcidine, dihydrolycorine, 8-O-demethylmaritidine, stylopine and protopine, nicotinic acid and tyramine were isolated from Galanthus trojanus A.P. Davis & N. Özhatay (Amaryllidaceae). The chemical structures of the isolates were elucidated by UV, IR, MS, CD, 1D and 2D NMR experiments. The in vitro antiprotozoal and cytotoxic potentials of the compounds were also evaluated.     

Phylogenetic analysis of Leucojum and Galanthus (Amaryllidaceae) based on plastid matK and nuclear ribosomal spacer (ITS) DNA sequences and morphology

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.     

Phylogenetic selection of Narcissus species for drug discovery

Plants are of immense importance in providing healthcare worldwide. With over 250 000 species of angiosperms alone, the potential for finding new medicinal plants and lead compounds for drug development is enormous. Some way of selecting plants for drug discovery programs is necessary. Phylogenies have great explanatory power and also enable a predictive perspective not offered by previous classifications of plants. Phylogenetic selection of target species is a new approach to drug discovery and the present study is the first attempt to correlate acetylcholine esterase (AChE) inhibitory activity and alkaloid distribution with a molecular phylogenetic hypothesis of Narcissus. The distribution of alkaloids with AChE inhibitory activity is significantly constrained by the phylogeny. Simultaneous evaluation of all available information of alkaloids and AChE inhibitory activity in a phylogenetic framework allowed us to discuss various strategies for selection of target species for further studies of AChE inhibitory activity.     

Chemical constituents of the bulbs of Haemanthus multiflorus

Six new (1–6) and four known (7–10) phenolic glycosides were isolated from the bulbs of Haemanthus multiflorus (Amaryllidaceae). The structures of the new compounds were determined on the basis of spectroscopic analysis and of chromatographic analysis of the hydrolyzed products. Moreover, compound 1 showed moderate cytotoxicity against HL-60 human promyelocytic leukemia cells.     

Genetic diversity of Allium munzii (Amaryllidaceae), a rare southern California species and implication for its conservation

An understanding of genetic diversity within and among populations of rare plant species is a prerequisite to develop effective conservation management strategies and reintroduction programs. Allium munzii is a narrow endemic species distributed in western Riverside County, California, USA and known from 18 extant element occurrences. We sampled 119 individuals from 11 element occurrences and investigated within and among population genetic diversity using two variable chloroplast markers (rpL32–trnL intergenic spacer and rpoC1 intron). Of the total genetic variation detected in A. munzii, 87.65% was due to differences among occurrences. Furthermore, our results revealed that most of the element occurrences are strongly genetically differentiated. There are low levels of gene flow between occurrences, not due to isolation by distance but possibly resulting from habitat fragmentation. Non-significant values of Tajima's D and Fu's Fs were found in all occurrences suggesting no demographic expansion in A. munzii. Ex situ seed and bulb conservation is recommended to enable introduction of individuals to occurrences with low abundance and genetic diversity.     

Influence of plant origin on propagation capacity and alkaloid biosynthesis during long-term <Emphasis Type="Italic">in vitro</Emphasis> cultivation of <Emphasis Type="Italic">Leucojum aestivum</Emphasis> L.

The investigation deals with in vitro clonal propagation of L. aestivum L. (summer snowflake), a threatened Amaryllidaceae plant species in Bulgaria used in the pharmaceutical industry as raw material for production of galanthamine-based medicines. Plants of known origin and with different alkaloid profile were taken from the living collection of the Institute of Botany, Sofia. Bulbs were used to initiate in vitro cultures and 24 clones were multiplied. The influence of the clone origin on the propagation coefficient, shoot and bulblet morphology, alkaloid profile and content of galanthamine, lycorine, and four related alkaloids was evaluated. Clones kept stable alkaloid profiles and for most of them, high regeneration rates were noted. Galanthamine content of some clones was commensurable with that of Bulgarian populations of L. aestivum of commercial importance. Five clones: four galanthamine-type and one lycorine-type were selected as promising for further investigation.     

First report of a glutamine-rich antifungal peptide with immunomodulatory and antiproliferative activities from family Amaryllidaceae

This represents the first report of purification of a glutamine-rich antifungal peptide from family Amarylliaceace. The peptide, designated as nartazin, was purified from the bulbs of the Chinese daffodil Narcissus tazetta var. chinensis by means of ion-exchange chromatography and affinity chromatography. Its molecular mass was 7.1kDa, as determined by SDS-PAGE and gel filtration. Nartazin stimulated proliferation of mouse splenocytes and bone marrow cells but inhibited proliferation of leukemia L1210 cells. It also inhibited translation in a cell-free rabbit reticulocyte lysate system. The sequence of its first 20 N-terminal residues was characterized by an abundance of glutamine. The peptide possessed antifungal activity on four phytopathogenic fungi. Its activity was retained after incubation with bovine trypsin and chymotrypsin (enzyme: substrate ratio 1:10 w/w) at 37 degrees C for 1h but was attenuated after treatment with proteinase K. The data revealed its pronounced resistance to proteolytic digestion.