Ambrein is a

triterpene Triterpenes are a class of terpenes composed of six isoprene units with the molecular formula C30H48; they may also be thought of as consisting of three terpene units. Animals, plants and fungi all produce triterpenes, including squalene, the pre ...

alcohol that is the chief constituent of

ambergris Ambergris ( or ; ; ), ''ambergrease'', or grey amber is a solid, waxy, flammable substance of a dull grey or blackish colour produced in the digestive system of sperm whales. Freshly produced ambergris has a marine, fecal odor. It acquires a sw ...

, a secretion from the digestive system of the

sperm whale The sperm whale or cachalot (''Physeter macrocephalus'') is the largest of the toothed whales and the largest toothed predator. It is the only living member of the Genus (biology), genus ''Physeter'' and one of three extant species in the s ...

. It has been suggested as the possible active component producing the supposed

aphrodisiac An aphrodisiac is a substance that increases libido, sexual desire, sexual attraction, sexual pleasure, or sexual behavior. These substances range from a variety of plants, spices, and foods to synthetic chemicals. Natural aphrodisiacs, such as ...

effects of ambergris. Although ambrein itself is odorless, it serves as the biological precursor for aromatic derivatives such as

ambroxide Ambroxide, widely known by the brand name Ambroxan, is a naturally occurring terpenoid and one of the key constituents responsible for the odor of ambergris. It is an autoxidation product of ambrein. Ambroxide is used in perfumery for creating a ...

and is thought to possess fixative properties for other odorants. It has been shown to act as an

analgesic An analgesic drug, also called simply an analgesic, antalgic, pain reliever, or painkiller, is any member of the group of drugs used for pain management. Analgesics are conceptually distinct from anesthetics, which temporarily reduce, and in s ...

and has been proven to increase sexual behavior in rats, providing some support for its traditional aphrodisiac use. Apart from its supposed aphrodisiac effects, ambrein has been shown to decrease spontaneous contractions of smooth muscles in rats, guinea pigs, and rabbits. It reduces these contractions by serving as an antagonist and interfering with Ca²⁺ ions from outside the cell.

Discovery

In 1946, Ruzicka and Lardon "established that the fragrance of

is based on the

(named) ambrein".

Biosynthesis

Ambrein is synthesized from the common triterpenoid precursor

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). ...

. The

squalene-hopene cyclase Squalene-hopene cyclase (SHC) () or ''hopan-22-ol hydro-lyase'' is an enzyme in the terpene cyclase/mutase family. It catalyzes the interconversion of squalene into a pentacyclic triterpenes, hopene and hopanol. This enzyme catalyses the following ...

(SHC) catalyzes the cyclization of

into the monocyclic 3-deoxyachilleol A.

Tetraprenyl-beta-curcumene synthase Tetraprenyl-β-curcumene synthase (EC 4.2.3.130, ''ytpB (gene)'') is an enzyme with systematic name ''all-trans''-heptaprenyl-diphosphate diphosphate-lyase (cyclizing, tetraprenyl-β-curcumene-forming). This enzyme catalyses the following chemical ...

(BmeTC) converts 3-deoxyachilleol A into the tricyclic ambrein.

References

{{reflist Perfume ingredients Whale products Animal glandular products Triterpenes Decalins Tertiary alcohols