Farnesol is a natural 15-carbon

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

which is an acyclic

sesquiterpene Sesquiterpenes are a class of terpenes that consist of three isoprene units and often have the molecular formula C15H24. Like monoterpenes, sesquiterpenes may be cyclic or contain rings, including many combinations. Biochemical modifications s ...

alcohol. Under standard conditions, it is a colorless liquid. It is

hydrophobic In chemistry, hydrophobicity is the chemical property of a molecule (called a hydrophobe) that is seemingly repelled from a mass of water. In contrast, hydrophiles are attracted to water. Hydrophobic molecules tend to be nonpolar and, thu ...

, and thus insoluble in water, but miscible with oils. As the

pyrophosphate In chemistry, pyrophosphates are phosphorus oxyanions that contain two phosphorus atoms in a linkage. A number of pyrophosphate salts exist, such as disodium pyrophosphate () and tetrasodium pyrophosphate (), among others. Often pyrophosphates a ...

ester, farnesol is a precursor to many terpenes and terpenoids.

Uses

Farnesol is present in many

essential oil An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the ...

s such as citronella,

neroli Neroli oil is an essential oil produced from the blossom of the bitter orange tree (''Citrus aurantium subsp. amara'' or ''Bigaradia''). Its scent is sweet, honeyed and somewhat metallic with green and spicy facets. Orange blossom is also extract ...

cyclamen ''Cyclamen'' ( or ) is a genus of 23 species of perennial flowering plants in the family Primulaceae. In English, it is known by the common names sowbread or swinebread. ''Cyclamen'' species are native to Europe and the Mediterranean Basin ea ...

lemon grass ''Cymbopogon'', also known as lemongrass, barbed wire grass, silky heads, oily heads, Cochin grass, Malabar grass, citronella grass or fever grass, is a genus of Asian, African, Australian, and tropical island plants in the grass family. Some ...

tuberose ''Agave amica'', formerly ''Polianthes tuberosa'', the tuberose, is a perennial plant in the family Asparagaceae, subfamily Agavoideae, extracts of which are used as a Note (perfumery), note in perfumery. Now widely grown as an ornamental plant, ...

rose A rose is either a woody perennial plant, perennial flowering plant of the genus ''Rosa'' (), in the family Rosaceae (), or the flower it bears. There are over three hundred Rose species, species and Garden roses, tens of thousands of cultivar ...

musk Musk is a class of aromatic substances commonly used as base notes in perfumery. They include glandular secretions from animals such as the musk deer, numerous plants emitting similar fragrances, and artificial substances with similar odors. ' ...

balsam Balsam is the resinous exudate (or sap) which forms on certain kinds of trees and shrubs. Balsam (from Latin ''balsamum'' "gum of the balsam tree," ultimately from a Semitic source such as ) owes its name to the biblical Balm of Gilead. Ch ...

, and tolu. It is used in perfumery to emphasize the odors of sweet, floral perfumes. It enhances perfume scent by acting as a co-solvent that regulates the volatility of the odorants. It is especially used in lilac and peony perfumes. Farnesol and its ester derivatives are important precursors for a variety of other compounds used as fragrances and vitamins.

Cosmetics

Farnesol is used as a

deodorant A deodorant is a substance applied to the body to prevent or mask body odor caused by bacterial breakdown of perspiration, for example in the armpits, groin, or feet. A subclass of deodorants, called antiperspirants, prevents sweating itself, t ...

in cosmetic products. Farnesol is subject to restrictions on its use in perfumery, because some people may become sensitised to it.

Natural source and synthesis

In nature

The pyrophosphate ester of farnesol is the building blocks of possibly all acyclic sesquiterpenoids. These compounds are doubled to form 30-carbon

squalene Squalene is an organic compound. It is a triterpene with the formula C30H50. It is a colourless oil, although impure samples appear yellow. It was originally obtained from shark liver oil (hence its name, as '' Squalus'' is a genus of sharks). ...

, which is the precursor for

steroid A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes t ...

s in plants, animals, and fungi.

Farnesyl pyrophosphate Farnesyl pyrophosphate (FPP), also known as farnesyl diphosphate (FDP), is the precursor to all sesquiterpenes, which comprises thousands of compounds. These include all sesquiterpenes as well as sterols and carotenoids. It is also used in the syn ...

is produced from the reaction of

geranyl pyrophosphate Geranyl pyrophosphate (GPP), also known as geranyl diphosphate (GDP), is the pyrophosphate ester of the terpenoid geraniol. Its salts are colorless. It is a precursor to many thousands of natural product, natural products. Occurrence GPP is an int ...

and

isopentenyl pyrophosphate Isopentenyl pyrophosphate (IPP, isopentenyl diphosphate, or IDP) is an isoprenoid precursor. IPP is an intermediate in the classical, HMG-CoA reductase pathway (commonly called the mevalonate pathway) and in the ''non-mevalonate'' MEP pathway of i ...

. Farnesyl pyrophosphate is the precursor to farnesol and farnesene. : Farnesyl pyrophosphate skeletal

Farnesol is used by the fungus ''

Candida albicans ''Candida albicans'' is an opportunistic pathogenic yeast that is a common member of the human gut flora. It can also survive outside the human body. It is detected in the gastrointestinal tract and mouth in 40–60% of healthy adults. It is usu ...

'' as a

quorum sensing In biology, quorum sensing or quorum signaling (QS) is the process of cell-to-cell communication that allows bacteria to detect and respond to cell population density by gene regulation, typically as a means of acclimating to environmental disadv ...

molecule that inhibits

filamentation Filamentation is the anomalous growth of certain bacteria, such as ''Escherichia coli'', in which cells continue to elongate but do not divide (no septa formation). The cells that result from elongation without division have multiple chromosomal ...

Commercial production

Obtaining farnesol from natural sources is uneconomical. In industry, farnesol is produced from

linalool Linalool () refers to two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants. Together with geraniol, nerol, and citronellol, linalool is one of the rose alcohols. Linalool has multiple commercial app ...

. :

History of the name

Farnesol was named (ca. 1900–1905) after the Farnese acacia tree (''Vachellia farnesiana''), since the flowers from the tree were the commercial source of the floral essence in which the chemical was identified. This particular acacia species, in turn, is named after Cardinal Odoardo Farnese (1573–1626) of the Italian Farnese family who (from 1550 though the 17th century) maintained some of the first private European botanical gardens in the Farnese Gardens in Rome. The addition of the -ol suffix implies an

alcohol Alcohol may refer to: Common uses * Alcohol (chemistry), a class of compounds * Ethanol, one of several alcohols, commonly known as alcohol in everyday life ** Alcohol (drug), intoxicant found in alcoholic beverages ** Alcoholic beverage, an alco ...

. The plant itself was brought to the Farnese gardens from the

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

and

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

, where it originates.{{cite journal , url=https://www.swsbm.com/AJP/AJP_1885_No_3.pdf , title=The Essential Oil Industry in Grasse , first=F. A. , last=Fluckiger , journal=American Journal of Pharmacy , volume=57 , issue=3 , date=March 1885

References

Fatty alcohols Alkene derivatives Sesquiterpenes Perfume ingredients Flavors Insect pheromones Primary alcohols