Search

The Jurassic relict Royal fern, Osmunda regalis L., is widely distributed across temperate zones in the Northern and Southern hemispheres. Even though this species has been utilised for centuries as a medicinal plant, its phytochemical composition mainly remains unknown. As part of our ongoing research to identify potential lead compounds for future anticancer drugs, 17 natural products were characterised from the aerial parts of Osmunda regalis L. Fifteen of these compounds were identified in this species for the first time, including the six previously undescribed compounds kaempferol 3-O-(2"-O-(2"'-α-rhamnopyranosyl)-β-glucopyranosyl)-β-glucopyranoside, quercetin 3-O-(2"-O-(2"'-α-rhamnopyranosyl)-β-glucopyranosyl)-β-glucopyranoside, kaempferol 3-O-(2"-O-(2"'-α-rhamnopyranosyl-6"'-O-(E)-caffeoyl-)-β-glucopyranosyl)-β-glucopyranoside, 3-methoxy-5-hydroxy-4-olide, 4-hydroxy-3-(3'-hydroxy-4'-(hydroxyethyl)-oxotetrafuranone-5-methyl tetrahydropyranone, and 4-O-(5-hydroxy-4-oxohexanoyl) osmundalactone. The molecular structures were determined by combining several 1D and 2D NMR experiments, circular dichroism spectroscopy, and HRMS. Determination of cytotoxicity against AML MOLM-13, H9c2, and NRK cell lines showed that two isolated lactones exhibited significant cytotoxic activity. [ABSTRACT FROM AUTHOR]

The genus Sorbus s.l. consists of small to medium‐sized trees primarily found in coastal areas, with three European hotspots of diversification: Fennoscandia, south‐east Europe and the British Isles. Taxonomic classification of Sorbus s.l. in Europe is still unresolved, and this study aims to address this issue by examining the pollen morphology of various Sorbus hybrids. Pollen morphology of 16 specimens from 13 species of Sorbus s.str., Aria and Hedlundia, some of them common, others are endemic and listed as threatened species, were studied. Measurements of the polar and equatorial axis of all pollen grains show that there are variations in pollen size and shape among different hybrids, with a correlation between ploidy levels and the equatorial diameter of the pollen. Surface structures of the pollen were observed using SEM. Principal component analysis (PCA) was performed to analyze the pollen characters, and the results show that it is possible to separate Aria from Sorbus and Hedlundia based on the length of the polar axis of the pollen grain, while the number of perforations is important for classification within Hedlundia. The study concludes that pollen morphology can be a useful tool for distinguishing between different Sorbus hybrids and can thus aid in understanding their past distributions. [ABSTRACT FROM AUTHOR]

North European epiphytic lichens are often genetically impoverished compared with their North American counterparts. This has been hypothesized to impede sexual reproduction due to reduced chances of finding compatible mating type partners. We compared genetic variation and reproductive mode in two threatened Scandinavian lichens, Evernia divaricata and Usnea longissima, with more viable populations in North America to see (i) if these species also show genetical depletion in northern Europe and (ii) if the occurrence of sexual propagules (ascospores in apothecia) is more prevalent in genetically diverse populations. Genetic variation of the fungal component was assessed by sequencing two nuclear rDNA gene regions (ITS andIGS) in 1005 and 1477 thalli, collected from 92 and 160 localities of E. divaricata and U. longissima, respectively. Scandinavian populations of both species were almost devoid of genetic variation compared with much higher genetic diversity in North America. We found no support for the proposed relationship between genetic diversity and fertility. Fertile thalli were found in several genetically invariable populations. Fertility increased with population size and regional abundance in E. divaricata, but not in U. longissima. In Scandinavia, E. divaricata was more fertile than previously recorded, whereas all sampled populations of U. longissima were sterile and possibly clonal. Key words: allelic richness, dispersal, epiphytic lichens, gene diversity, old-growth forests. Les lichens epiphytes europeens sont souvent appauvris genetiquement, comparativement a leurs contreparties americaines. On a formule l'hypothese que ceci nuirait a la reproduction sexuelle, du a la reduction des chances de trouver un partenaire de type de croisement compatible. Les auteurs ont compare la variation genetique et le mode reproducteur chez deux lichens scandinaves menaces, l'Evernia divaricata et l'Usnea longissima, avec des populations plus viables de l'Amerique du Nord afin de verifier (i) si ces especes montrent egalement un epuisement genetique dans le nord de l'Europe et (ii) si la presence de propagules sexuelles (ascospores dans des apotheces) prevaut plus fortement dans des populations genetiquement diverses. Les auteurs ont evalue la variation genetique de la composante fongique en sequencant deux regions du gene nucleique tADN (ITS et IGS) chez 1005 et 1477 thalles recoltes a partir de 92 et 160 localites, pour l'E. divaricata et l'U. longissima, respectivement. Les populations scandinaves des deux especes sont pratiquement depourvues de variation genetique comparativement a une diversite genetique tres fortement marquee en Amerique du Nord. Il n'ont trouve aucun support pour la proposition suggerant une relation entre la diversite genetique et la fertilite. On a retrouve des thalles fertiles dans plusieurs populations genetiquement invariables. La fertilite augmente avec la dimension de la population chez l'E. divaricate, mais non chez l'U. longisima.En Scandinavie, l'E. divaricata s'avere plus fertile que reconnu jusqu'ici, alors que toute les populations echantillonnees de l'U. longissima se sont averees steriles et possiblement clonales. [Traduit par la Redaction] Mots-cles: richesse allelique, dispersion, lichens epiphytes, diversite genetique, forets surannees., Introduction Lichens are symbiotic associations of heterotrophic fungi and photosynthetic green algae and (or) cyanobacteria. They represent an important part of the biodiversity in terrestrial arctic and boreal ecosystems, being [...]

The two corticolous species Fuscidea lightfootii (Sm.) Coppins & P. James and F. pusilla Tønsberg are morphologically and chemically similar and it has been suggested that they are conspecific. We investigated the interspecific relationship between F. lightfootii and F. pusilla using ITS, LSU and mtSSU rDNA. The combined multigene phylogeny shows that these species are genetically distinct. They are similar in ascocarp anatomy but in thallus morphology and substratum preferences there may be slight differences between them. Moreover, F. pusilla displays a broader ecological range than F. lightfootii. Even though some morphotypes appeared distinct and may be assigned to one of the two species with some degree of certainty, the use of DNA sequencing is recommended for their identification. Epitypes are designated for both species. [ABSTRACT FROM AUTHOR]

Based on morphometric and molecular methods, the taxonomy of the infraspecific taxa of Fuscidea cyathoides (Ach.) V. Wirth & Vězda, var. corticola (Fr.) Kalb and var. sorediata (H. Magn.) Poelt, has been assessed. No formal taxonomic recognition should be attributed to the morphological and ecological variation. Accordingly, var. corticola and var. sorediata are synonymized with F. cyathoides var. cyathoides. New synonyms at the specific level are Fuscidea fagicola (Zschacke) Hafellner & Türk and F. stiriaca (A. Massal.) Hafellner. [ABSTRACT FROM AUTHOR]