Exudate flavonoid aglycones in the alpine species of Achillea sect. Ptarmica: Chemosystematics of A. moschata and related species (Compositae-Anthemideae).

In completion of our studies on Achillea exudate flavonoids, 11 alpine species of Achillea sect. Ptarmica were analyzed for their aglycone profiles. The study focuses on species commonly associated with A. moschata. The major flavonoid constituents found in exudates of most taxa were 6-hydroxyflavonol 3,6,4'-trimethyl ethers, except in A. ageratifolia and its subspecies, which are characterized by the accumulation of the 3,6,7-trimethoxy and 6-hydroxyflavones. Infraspecific variation was particularly high in A. abrotanoides and A. moschata. Results are discussed in relation to published data for related species and within the context of evolutionary aspects in the genus Achillea. The 3,6,4'-trimethoxy substitution is regarded as a basic chemical trend within the genus Achillea. Geographical and ecological aspects are briefly addressed, and a summary on known exudate aglycone composition of species from all sections of Achillea is included.