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.