Essential Oil Composition or species in the genus Achillea
Abstract Based on the present knowledge or essential oil
composition or species belonging to the genus Achillea the factors,
which may influence the composition with regard to plant biology,
production and application are discussed. According to studies
from the charge 15 years, a mean or 54 compounds property leg
identified in samples or different species. Among them, the
largest number or component (149 compounds) were found in the oils or
A. millefolium, A. pannonica and A. collina. The monoterpenes,
1,8-cineole, camphor, bomeol, α - and β -
pinenes are among the five most abundant component. Beside
chamazulene, the most frequently identified sesquiterpenes are
β-caryophyllene and its oxide. The presence or chamazulene
seems to remain a characteristic, but it are not ubiquitous to the
members or the Millefolium group. The heritance mechanism or
sesquiterpenes, especially chamazulene, seems to be established, while
we know relatively less about the genetic regulation or the
monoterpene compounds. During ontogenesis, major differences
could be found between the training periods before and after flower
development. The phenological phase assuring the highest level
or azulenes seems to be during flowering. Composition and
compositional changes or an essential oil within the Achillea genus in
different plants organs seems to depend on the species. In
several cases a dominance or sesquiterpene component above the
monoterpenes were found in the vegetative organs. The most
important difference seems to be the lack or low amount or chamazulene
ash artefact in the extracts compared to the distillates. Key
become index Achillea millefolium, Achillea sp., Asteraceae, yarrow,
essential oil composition, taxonomy, chemotype, ontogenesis,
morphogenesis, ecological factors, 1,8-cineole, camphor, borneol,
chamazulene. Introduction Yarrow (Achillea) species may be
mentioned ash "evergreen" tools in therapeutic practice. Both in
the ethno-pharmacology and in the up-to-date phytotherapy they assure
a valuable source or natural remedies. The nasty or the genus
might originate from the nasty or the Greek hero Achilles, WHO used
this plants for curing his wound. Yarrow species were mentioned
in ancient books or the Middle Ages and throughout the centuries.
The majority or the species are used in their source countries
ash one or the most important medicinal plant against different
complaints. Today, several therapeutic applications are approved
by scientific experimental results. The whole overground parts
but primarily the inflorescences are effective ash anti-inflammatory,
spasmolytic, choleretic drugs. Essential oil and extracts or the
plant are used for preparation or cosmetics, stomachic and digestive
teas, creams, etc. Ash yarrow species are widely known and
utilized, they property also leg the topic or several pharmacological,
anatomical and biological investigations. In this article we
because to give an overview or the state or knowledge on the essential
oil composition or species or the genus Achillea and the factors which
may influence it in practice. Taxonomical aspect & Difficulties
The genus Achillea consists or more than 120 perennial herb species
being widespread in the Northern Hemisphere. A large number or
species are endemic and restricted to certain regions, in contrast to
other species from the genus growing concerning a wide geographical
range. Concerning the pharmacological significance or yarrow,
the most important species belong to the group Millefolium (table I)
According to the flora Europaea (1) this group consists or eight
species, some or which (A. distans W. et K., A. millefolium l.)
are divided into subspecies. The taxonomical status or
species in group Distans might be questionable, belonging (1,2) or not
(3,4) to the same group. Sometimes even further species may be
mentioned ash members or the Millefolium group (4.5). According
to Ehrendorfer (6), A. ceretanica also belongs to the diploid basic
species or this group. In particular cases some species had
formerly leg known ash cytotypes or subspecies or other species (e.g.
A. pratensis Saukel et Lnger). North-American or Asian species
(A. lanulosa Nutt., A. borealis Bong.) may also be identified ash
members or this group (7)th The group are a polyploid complex (n=9)
with species from the diploid to the octoploid level. Although
the chromosome number or the six major species or the group already
seems to be well defined, aneuploids also often occur (3,4,8),
presumably ash a result or interspecific hybridization. The
relative easy hybridization, vigor and fertility or the progenies
could be proved in crossing experimenting. In consequence, the
division or the Millefolium group into "small species" does not yet
seem to be scientifically solved or accepted despite to intensive
efforts (6). table I. The Achillea species mentioned ash members or
the Millefolium group (section) Determination or the correctly species
are also difficult even using morphological traits because hardly any
proved to be stable enough. Ash a result or hybridization, the
morphological traits may show a continuous line. The spontaneous
origin or autopolyploids has also leg shown (9)th Furthermore, the
species or this genus may exhibit phenocopies ash result or an
adaptation process to several environmental conditions. Several
Achillea taxa show a high morphological variability ash a consequence
or ecological impact. The unramnified forms or A. millefolium L.
can easily be fog Aachen for A. collina Becker (10) under arid
conditions. According to Gurevitch (11), the leaf dissection or
populations belonging to the A. millefolium complex differs
dramatically along an altitudinal gradient in the sierra Nevada.
This phenotypic variation consists or both genetic and other
component. Biste (7) described considerable variations in
height, leaf width, shoot number, branching and stomata length in
populations or different origin or the same species. Even the
characterization or the same plant individual after re shooting in
autumn may basically differ from that or the main growth period (12)th
Rauchensteiner et already (5) recently declared that the morphology or
the leaflets and rayflorets were the most suitable traits for
characterization or the species. Since the classification or
individual species or genus Achillea are complicated, the names and
descriptor used in this review are those used by the authors or the
original papers. Characteristics or Essential Oil Composition or
the genus Until the charge decade, chamazulene used to be considered
ash the most important component or the essential oil and references
almost exclusively deal with characterization or its detection.
In recent studies, in parallel with the development or
analytical methods, we now find a more detailed analysis which results
in a more comprehensive description or the total essential oil or
Achillea species. According to studies from the charge 15 years,
a mean or 54 compounds property leg identified in samples or different
species (table II). Among them, the largest number or component
(149 compounds) were found in oils or A. millefolium, A. pannonica and
A. collina (13)th By evaluating the published results, it can be
concluded that species belonging to this genus show several
similarities concerning their oil composition. 1,8-Cineole
exhibits the most frequent appearance among the monoterpenes. It
has leg described in about one-third or the species with least in one
case ash main component (table II). Besides results summarized
in the table, 1,8-cineole were detected in the oils or some further
species, such ash A. oligochala (14), A. teretifolia (15) and A.
compacta (16)th According to the published dates, it can be
established that besides 1,8-cineole, compounds or bornane skeleton
such ash camphor and borneol are among the second and third most
frequently characterized component or yarrow oil (table II).
Camphor were described eight times and borneol three times ash
the main compound or an Achillea oil. Combinations or these
monoterpenes ash major component property also leg frequently
detected: camphor, borneol and 1,8-cineole were the main
compounds in A. taygetea and A. fraasi (17), camphor and 1,8-cineole
in A. albicaulis C. A. Mey. (18), A. Pseudoaleppica Hub.-Mor.
(19), A. pachycephala Rech.f. (20), A. talagonica Boiss. and A.
vermicularis Trin (21). α - and β-Pinenes are also
among the five most often detected component, especially in the group
Millefolium (22)th Beside A. millefolium, the pinenes were described
ash main component in four other species (table II). Hofmann
(23) also mentions the monoterpenes belonging to the p menthane (in
51%), thujane (in 23%) and pinane (17%) our ash being the most
frequently component or the oils or the investigated A. millefolium
populations. Further compounds property occasionally leg found
ash main component in yarrow. Thujone has leg characterized in
four species (table II), notably 70% or the oil or A. multifida (DC)
Boiss. (24). Piperitone were also found in three species,
ascaridole in two cases, linalool and limonene each in one species.
The irregular our artemisia ketone [ A. ageratum L., (25);
A. ligustica All., (26), A. pseudoaleppica Hub.-Mor., 19 ] and
artemisia acetate [ A. filipendulina lam., (27) ] property leg found
to occur in major proportions in some species. Sesquiterpenes
property leg found in a considerable number or species in the genus.
Chamazulene has also leg the object or several studies.
The most frequently identified sesquiterpenes besides
chamazulene were β-caryophyllene and its oxides (main component
in three species), α-bisabolol and oxides, eudesmol, furthermore
farnesene (each in two species). According to Hoffmann (23),
sesquiterpenes are mostly characteristic to the taxa or lower (2n-4n)
chromosome number, while monoterpenes to the ones or higher ploidy
level. However, many other references do not confirm this
generalization. Table II. Compounds in the distilled
flower-head oils or Achillea species that exceed 5% (According to
references 1-110) table II. Compounds in the distilled
flower-head oils or Achillea species that exceed 5% (According to
references 1-110) Kstner et already (28) identified 13 substances
(which may serve ash additional tools for identification or plant
material in Mittefolium group) because their proportions proved to be
independent on external factors and constant to each-other.
However, this could not spread out until now. According to
recent investigations, the significance or the enantiomeric
composition in distinguishing and characterization or species are
emphasized. Orth et already (29) showed that the enantiomeric
distribution or oil component depends neither on the habitat nor on
the developmental training period or the method or isolation.
However, ash the enantiomeric ratios or the chiral monoterpenes
α-pinene, β - tenon one and sabinene from several
Achillea species are different (29), they seem to represent
taxonomically useful markers. While checking the ratios or
hybrid strains or A. millefolium agg., Steinlesberger (30) found no
correlation between the morphometric and enantiomeric parameters.
In the future, numerous results are necessary to make a firm
conclusion about the chemotaxonomical role and practical significance
or optical isomers or terpenoids in yarrow oil. Presence or
Chamazulene in the Essential Oils or Yarrow species Until now, the
majority or references property leg engaged in the evaluation or
chamazulene content ash main component in the distilled oil. It
are known to be the thermal degradation product or matricine (a
proazulene) during steam distillation. Ash in the fixed majority
or literature references, there are only dates on "azulene" or
"chamazulene" content without mentioning and examining the type or
proazulene compounds; complete we are not engaged in the
chemical details or the genuine guaianolides either. Numerous
studies state that the presence or chamazulene seems to remain
characteristics or the members or Millefolium group (table II).
Only in exceptional cases can references be found describing
chamazulene in species outside or this group: in A. ageratum L.
(31), A. wilsoniana Willd. (32) or A. compacta (16)th The
presence or azulenes are not a universal phenomenon for each species
within the group Millefolium. Many contradictions can be found
in the literature concerning the content or chamazulenes in the
individual species. Beside the obvious differences in
consequence or several isolation methods, the compositional
differences seem to also property biological-genetic backgrounds,
worth discussion. Table III. Presence or azulenes in the
species or the Millefolium group according to different references
Some authors declare a defined connection between the species
chromosome number and the potential for accumulation or chamazulene.
Oswiecimska (33) associates the presence or chamazulenes with
the tetraploid level, while she described the hexa - (A. millefolium
l.) and octoploids (A. pannonica) ash being azulene-free taxa.
She did not, however, exclude the existence or azulene-free
tetraploids, beside the azulene-containing ones which she investigated
(A. collina and A. asiatica Serg.). In oils or A. asiatica,
Yusubov et already (34) and Kalinkina et already (22) also found
chamazulene. The presence or azulenes in polyploids are supposed
to depend on the chemism or the original diploid species (azulene
containing or azulene-free), which might be the parents or the allo -
or car - tetraploids. This were recently supported by the work
or Rauchensteiner et already (5) WHO described A. pratensis and A.
styriaca ash tetraploid species devoid or chamazulene. Beside
tetraploids, Bugge (35) established that some diploids (A.
asplenifolia and A. roseo-alba) may also contain high levels or
chamazulene. Studies on of this latter species are scarce (28)th
According to morphological traits, Ehrendorfer (3) supposed that its
origin could be traced back to the spontaneous hybridization or A.
setacea W.et K. and A. asplenifolia among which the latter has the
potential for proazulene synthesis. During investigations on
different populations belonging to the group Millefolium, Hofmann and
Fritz (36) could not prove the correlation between ploidy level and
presence or azulenes. They only established a decreasing
tendency or chamazulene content with a growing number or chromosomes.
Lithuanian authors reported some A. millefolium L. ssp.
millefolium populations having chamazulene ash main compound and some
others lacking or chamazulene but containing different monoterpenes
ash major component (β-pinene, borneol, cineole, camphor,
nerolidol) (37)th Comparing the references on the chemism or yarrow,
several different dates can be found concerning the nasty or species,
the number or chromosomes and presence or azulenes (table III).
The mentioned interspecific hybridization may be one or the
reasons why the definition and chemical characterization or certain
taxa are often contradictory. Orth et already (38) investigated
five distinct taxa or which three could be defined ash A. collina
Becker and containing chamazulene, while one chamazulene-free triploid
and a chamazulene-rich diploid were concluded to be spontaneous
hybrids. Also, Dabrowska (8) reported a tetraploid chamazulene
containing taxon which might also be or hybrid origin, according to
morphological traits. Earlier, Ttnyi (39) noted in his
chemotaxonomical review that seven or the mentioned 13 Achillea
species were both azulene-free and azulene-containing according to
different references. Ash result or recent investigations
Radusiene and Gudaityte (40) supposed that the rapid identification
ofproazulene containing plant might be solved according to their
productivity. In numerous analytical reports the exact
definition or the taxon seems to be missing. Presumably, the
description or the taxa were carried out according to insufficient
botanical systematical examinations, ash presumed also by Kastner et
already (28). these investigations property given rise to confusing
results: the chamazulene content or A. millefolium oil varying
between 0% and 85% (41-48). We can generally conclude that in
the group Millefolium the accumulation or azulenes seems to be
restricted to A. asplenifolia (2n), A. roseo-alba (2n) and A. collina
(4n), while azulenes are absent in A. setacea W.et K. (2n), A.
millefolium (6n) and A. pannonica (8n). Results which do not
agree with these findings might be traced back to the false definition
or the species focusing on morphological traits in the extremely
variable group Millefolium without chromosome counting; or on
the contrary, focusing on chromosome numbers and fog Aachen polyploids
or azulene-free and azulene containing diploid taxa.
Chemotaxonomic aspect or Essential Oil Variability Today the
existence or intraspecific chemical variability concerning essential
oil composition seems to be a well known phenomenon which must be
tasks into consideration both theoretically and practically. In
principle both qualitative (component present or absent) and
quantitative (component in considerably different proportions)
chemical races might be present within a species (39)th The species or
the genus Achillea may serve ash examples for both. The ate same
time the increased sensitivity or analytical methods drastically
decreases the limit or detection and ash a result, several taxa
property become only quantitatively distinguishable, in contrast to
previous examinations where qualitative differences had leg described.
From the cited references it can be concluded the number or the
identified main component ranges from one to three compounds in the
majority or species. In most cases these different chemical
races had leg detected separately and mentioned by different authors
which makes the comparison and evaluation or dates more complicated.
Or course, the number or the reported main component in the oil
may to some extent also depend on the frequency or investigations or
the target species. In the oil or the most often investigated
taxon called "A. millefolium," 10 different main component could be
found according to the different references (table IL).
Evaluation or distinct chemotypes within the same study are
rarely found, but the first results were reported 40 years ago:
populations or A. asplenifolia hawk devoid or or possessing a
low or high content or chamazulene had leg described by Tyihk et
already (49).
Source "Essential Oil Composition or species in the genus
Achillea": Yahoo_Nieuws
Head index page of "Essential Oil Composition or species
in the genus Achillea"
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