Description
Refer to LABDANUM, ABSOLUTE.
Chemical Properties
Labdanum absolute is produced by extraction of the gum with alcohol (e.g.,
methanol or ethanol). The so-called colorless absolutes are obtained from absolutes
by extraction with, for example, hexane.
Steam distillation of the gum yields labdanum oil, which is a golden yellow, viscous
liquid that quickly turns dark brown on standing:
d
2525 0.905–0.993; n
20D 1.4920–1.5070; α
20D +0°15′to +7°, often difficult to determine
due to its dark color; solubility: 1 vol in 0.5 vol of 90% ethanol, solutions
frequently opalescent to turbid, paraffinsmay separate upon further dilution; acid
number: 18–86; ester number: 31–86.
Cistus oil and extracts are products with completely different sensory properties.
They are derived from the leaves and young twigs of C. ladanifer. Cistus oil
is obtained by steam distillation; solvent extraction yields cistus concrete. Cistus
oil, in contrast to labdanum oil, consists mainly of monoterpene hydrocarbons.
Cistus and labdanum products are produced in some Mediterranean countries
(Spain, France,Morocco), where the Cistus shrub grows abundantly.They are used
in perfumery, giving perfume compositions awarm, balsamic tonalitywith a touch
of ambergris. The typical odor originates from a number of compounds that are
formed by oxidative degradation of diterpenes with the labdane skeleton, which
are the main constituents of labdanum gum. The resinoids and
absolutes are excellent natural fixatives.
Chemical Properties
Shrubs growing in thickets in several Mediterranean islands (Crete,
Cyprus) and countries (Spain particularly). In the Spanish region
of Zamora, C. ladaniferus L. and its varieties-C. albiflorus Dun.,
C. stenophyllus Dun.t C. maculatus D un-are predominant. On the
other hand, the extractive use of C. creticus growing on the island
of Crete is steadily decreasing.
Labdanum resin consists of the secretion of the glandular hairs
covering the inferior part of the leaves (spring and summer). The
hairy leaves and twigs are treated with boiling water, and the
floating resin is skimmed from the surface. Crude labdanum resin
is a dark brown, semisolid mass with a very pleasant, balsamic
odor reminiscent of ambergris and a bitter taste.
In the past, the resin was harvested by using a special whip (con sisting of several leather strips) to flog the plant. The leather strips
would become impregnated with the gum resin, which was sub sequently shaved off with special blades. This method is no longer
used. To prepare a colorless product, the crude resin can be
extracted with filtered ligroin, and finally the solvent is evaporated.
The parts used are the leaves and twigs from which the gum resin
is removed. The gum resin is used to prepare derivatives. The
organoleptic characteristic of labdanum is a sweet, herbaceous,
balsamic odor reminiscent of ambergris with a rich, lasting, ani mal-like undertone.
The essential oil, obtained by steam distillation of the crude gum
resin, is a bright-yellow liquid that turns brown with age. It has a
strong, balsamic odor reminiscent of ambergris on dilution. Phys ical-chemical constants of the oil follow:An essential oil, called cistus oil, is also steam distilled directly
from the dried leaves and twigs. This oil is a pale-orange liquid with a characteristic herbaceous odor reminiscent of camomile.
The main constituents that have been identified in labdanum oil
are terpenes, benzaldehyde, acetophenone, a ketone with a pep permint odor, acetic acid, and eugenol.
The derivatives are concrete, absolute, and resinoid and resin abso lute.
Concrete: The concrete is prepared by hydrocarbon extraction of
dried (in the shade) and comminuted leaves and twigs. It is a dark green mass with a pleasant balsamic, herbaceous odor. The phys ical-chemical constants vary widely, depending on the source.
Chemical Properties
The oil, obtained by steam distillation of the crude gum resin, is a bright-yellow liquid that turns brown with age. It has
a strong, balsamic odor reminiscent of ambergris on dilution. There is also an oil called cistus oil, which is steam-distilled directly
from the dried leaves and twigs. The oil has a characteristic herbaceous odor reminiscent of chamomile
Chemical Properties
Shrubs growing in thickets in several Mediterranean islands (Crete, Cyprus) and countries (Spain, particularly). In the
Spanish region of Zamora, C. ladanifer L. and its varieties are predominant. On the other hand, the extractive use of C. creticus
growing on the island of Crete is steadily decreasing. The part used is resin gum from leaves and twigs. Labdanum has a sweet, herbaceous, balsamic odor reminiscent of ambergris with a rich, lasting, animal-like undertone
Chemical Properties
Prepared by alcoholic extraction of the concrete in approximately 55 to 60% yields. The absolute consists of a semisolid, olive-green mass with a characteristic ambergris odor
Occurrence
Found in the gum of the shrub Cistus ladaniferus L
Preparation
By steam distillation of the crude gum
Definition
Extractives and their physically modified derivatives. Cistus ladaniferus, Cistaceae.
Essential oil composition
The oil contains α-pinene (3.5%), camphene (11%), limonene (2.6%), γ-terpinene (2%), bornyl acetate
(4.2%), α-thujone (0.8%), carophylline (0.47%), δ-phellandrene (0.41%), linalool (0.5%), eucalyptol (0.2%), cadinene (0.3%), benzaldehyde,
myrcene, p-cymene (4%), eugenol (trace). Levels of some components vary depending on the harvesting time (CoE, 2000).
Also see Labdanum oil.
Essential oil composition
The main constituents of the oil include terpenes, benzaldehyde, acetophenone, a ketone with a peppermint
odor, acetic acid and eugenol.
