Chemotaxonomic relevance of sesquiterpenes within the Achillea millefolium group

Sesquiterpene Lactones from Achillea collina Becker

“…Based on chemical and cytological investigations of different A. millefolium taxa collected throughout Central Europe, the Vienna school demonstrated that guaianolides (both proazulene and nonazulenogenic) characterized all diploid species, but only A. collina and A. ceretamica of the tetraploid species (Kubelka et al, 1999). In contrast, A. collina of Bulgarian origin was proved to produce germacranolides and eudesmanolides only.…”

“…Previous chemical studies on this species revealed the presence of lactones belonging to the guaiane type only. The main lactones were reported to be artabsin derivatives (VerzarPetri et al, 1980;Kastner et al,1991a;Kastner et al, 1991b;Kubelka et al, 1999), although a matricin derivative (Verzar-Petri et al, 1980) and a matricarin derivative (Glasl et al, 1994) were also isolated. In contrast, we could not detect any other lactones but germacranolides and eudesmanolides.…”

Millifolides A–C. New 1,10-Seco-guaianolides from the Flowers of Achillea millefolium

“…The signals at δ = 201.6, 170.0, 139.0, and 207.4 implied the presence of an α,β -unsaturated group and an unconjugated keto carbonyl unit. Additionally, the 13 C NMR spectrum indicated the presence of an oxygenated carbon at δ = 77.5 (C-3), three methylene and two methyl groups and one methine carbon. The 1 H NMR spectrum displayed the characteristic signals of exocyclic methylene protons at δ = 6.36 (1H, d, J = 2.6 Hz, H13a) and 5.67 (1H, d, J = 2.6 Hz, H-13b), a proton vicinal to the oxygen of the lactone ring at δ = 4.96 (1H, d, J = 5.0 Hz, H-6), one allylic methyl group at δ = 2.10 (3H, s, Me-15) placed in the β -position of an α,β -unsaturated keto carbonyl group and a methyl group connected to a keto carbonyl group at δ = 2.15 (3H, s, Me-14).…”

“…This observation suggested that the two partial structures were asymmetrically connected not by an ether but by an ester linkage. Indeed, the resemblance of the 1 H and 13 C NMR signals of the right hand part indicated that ester 2 was composed of achimillic acid A [7] and iso-seco-tanapatholide (4). The connection was elucidated by the crucial longrange proton-carbon correlation between H-3 and C-12 in the HMBC experiment.…”

Essential oil composition of two yarrow taxonomic forms

“…Studies of plant secondary metabolites can provide additional characteristics for taxonomic differentiation. Some authors [1,2] have reported that relative ontogenetic stability of sesquiterpenoids or essential oil composition in A. millefolium group could be a taxonomically useful tool for classification within the species. Several phytochemical studies previously focused mainly on azulenes and proazulenes (sesquiterpenic lactones) as the most characteristic compounds in yarrow plants [1,[3][4][5][6][7][8][9].…”