Flavones and flavonol glycosides fromEupatorium cannabinum L

The 6-methoxyflavones hispidulin and eupafolin have been identified for the first time from the aerial parts ofEupatorium cannabinum L. The presence of the previously known flavonol glycosides astragalin, kaempferol-3-rutinoside, hyperoside, isoquercitrin and rutin could be confirmed. Hispidulin, eupafolin and rutin were screened for cytotoxicityin vitr

Flavonoid variation in Eurasian Sedum and Sempervivum

Flavonoids from vegetative parts of 29 species of Eurasian Sedum, Sedum meyeri-johannis from central East Africa, 34 species of Sempervivum, and Jovibarba heuffelii have been identified after acid hydrolysis. Ten flavonoid aglycones were detected, i.e. kaempferol, herbacetin, sexangularetin, quercetin, gossypetin, corniculatusin, isorhamnetin, limocitrin, myricetin, and possibly hibiscetin. Quantitative flavonoid data were obtained by gas chromatography after trimethylsilylation and were studied with multivariate data analysis methods. Principal components analysis of the whole data set distinguishes Sedum and Sempervivum as separate groups. Flavonoid variation in Sempervivum is minimal (kaempferol is the principal flavonol of all species), which reflects the morphological uniformity of the genus and similarity in ecological preference of the species. By contrast, Eurasian Sedum contains a much wider range of flavonols and shows a high degree of parallel evolution (notably 8-hydroxylation and 8-O-methylation), which seems to mirror the enormous morphological and cytological variation present in this taxon. The recognition of groups in Sedum by principal components analysis of flavonoid data partially supports the infrageneric classification based on biosystematic data

Biosystematic, molecular and phytochemical evidence for the multiple origin of sympetaly in Euroasian Sedoideae (Crassulaceae)

Traditionally the sympetalous, Eurasian Crassulaceae are classified in four gen-era, but combined biosystematic, molecular and chemotaxonomic studies indicate that sympetaly evolved at least eight times independently in European Crassulaceae. Morphologically Umbilicus is very distinct and at the molecular level it also represents a distinct evolutionary lineage. The other three sympetalous genera evolved from the large paraphyletic genus Sedum. Of these three taxa Pistorinia represents a monophyletic lineage, whereas Mucizonia and Rosularia, are polyphyletic. The results of the hybridization experiments and molecular analyses justify the transfer of the Mucizonia species to the polypetalous Sedum series Dasyphylla and S. series Pedicellata, respectively. Cytological, phytochemical and molecular evidence indicate that Rosularia sect. Rosularia and R. sect. Chrysantha represent independent evolutionary lineages. Moreover, cpDNA restriction site analysis indicates a close relationship between R. sect. Chrysantha; and the comparium comprising Prometheum pilosum, P. sempervivoides and P. tymphaeum which were formerly included in Sedum. consequently R. sect. Chrysantha was transferred to Prometheum. Phytochemically, however, this genus is rather diverse. in addition to these six taxa, sympetaly evolved independently in Sedum lagascae, which is closely related to polypetalous S. villosum, and in S. series Alsinefolia, which,in our molecular analyses appears to be related to polypetalous S. hispanicum. (C) 1999 Elsevier Science Ltd. All rights reserved

Isolation of two cytotoxic diterpenes from the fern Pteris multifida

From aerial parts of the fern Pteris multifida Poir. (Polypodiaceae) two diterpenes, ent-kaurane-2 beta,16 alpha-diol and ent-kaur-16-ene-2 beta,15 alpha-diol, were isolated by repeated column chromatography using silica gel and silica gel impregnated with silver nitrate. The structures were confirmed by spectroscopic methods. Both compounds showed a moderate cytotoxicity to Ehrlich ascites tumour cells