Sotolon (also known as sotolone) is a

lactone Lactones are cyclic carboxylic esters, containing a 1-oxacycloalkan-2-one structure (), or analogues having unsaturation or heteroatoms replacing one or more carbon atoms of the ring. Lactones are formed by intramolecular esterification of the co ...

and an extremely powerful

aroma compound An aroma compound, also known as an odorant, aroma, fragrance or flavoring, is a chemical compound that has a smell or odor. For an individual chemical or class of chemical compounds to impart a smell or fragrance, it must be sufficiently v ...

, with the typical smell of fenugreek or

curry A curry is a dish with a sauce seasoned with spices, mainly associated with South Asian cuisine. In southern India, leaves from the curry tree may be included. There are many varieties of curry. The choice of spices for each dish in trad ...

at high concentrations and maple syrup, caramel, or burnt sugar at lower concentrations. Sotolon is the major aroma and flavor component of fenugreek seed and

lovage Lovage (), ''Levisticum officinale'', is a tall perennial plant, the sole species in the genus ''Levisticum'' in the family Apiaceae, subfamily Apioideae. It has been long cultivated in Europe, the leaves being used as a herb, the roots as a veg ...

, and is one of several aromatic and flavor components of artificial maple syrup. It is also present in molasses, aged

rum Rum is a liquor made by fermenting and then distilling sugarcane molasses or sugarcane juice. The distillate, a clear liquid, is usually aged in oak barrels. Rum is produced in nearly every sugar-producing region of the world, such as the Ph ...

, aged sake and white wine, flor

sherry Sherry ( es, jerez ) is a fortified wine made from white grapes that are grown near the city of Jerez de la Frontera in Andalusia, Spain. Sherry is produced in a variety of styles made primarily from the Palomino grape, ranging from light versi ...

, roast tobacco, and dried fruiting bodies of the mushroom ''

Lactarius helvus ''Lactarius helvus'', commonly known as fenugreek milkcap, is a member of the large milkcap genus '' Lactarius'' in the order Russulales. Fruiting bodies can be found in ''Sphagnum'' moss in coniferous and deciduous woodland in Europe, and possi ...

''. Sotolon can pass through the body relatively unchanged, and consumption of foods high in sotolon, such as fenugreek, can impart a maple syrup aroma to one's sweat and urine. In some individuals with the genetic disorder

maple syrup urine disease Maple syrup urine disease (MSUD) is an autosomal recessive metabolic disorder affecting branched-chain amino acids. It is one type of organic acidemia. The condition gets its name from the distinctive sweet odor of affected infants' urine and ear ...

, it is spontaneously produced in their bodies and excreted in their urine, leading to the disease's characteristic smell. This molecule is thought to be responsible for the mysterious maple syrup smell that has occasionally wafted over Manhattan since 2005. Sotolon was first isolated in 1975 from the herb fenugreek. The compound was named in 1980 when it was found to be responsible for the flavor of raw cane sugar: ''soto-'' means "raw sugar" in Japanese and ''-olon'' signifies that the molecule is an

enol In organic chemistry, alkenols (shortened to enols) are a type of reactive structure or intermediate in organic chemistry that is represented as an alkene ( olefin) with a hydroxyl group attached to one end of the alkene double bond (). The t ...

. Several aging-derived compounds have been pointed out as playing an important role on the aroma of fortified wines; however, sotolon (3-hydroxy-4,5-dimethyl-2(5H)-furanone) is recognized as being the key odorant and has also been classified as a potential aging marker of these type of wines. This

chiral Chirality is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek (''kheir''), "hand", a familiar chiral object. An object or a system is ''chiral'' if it is distinguishable from i ...

lactone is a powerful odorant, which can impart a nutty, caramel, curry, or rancid odor, depending on its concentration and enantiomeric distribution. Despite being pointed out as a key odorant of other fortified wines, the researchers’ attention has also been directed to its off-flavor character, associated to the premature oxidative aging of young dry white wines, overlapping the expected fruity, flowery, and fresh character. This compound can be detected by miniaturized emulsification extraction followed by GC–MS/SIM and single-step miniaturized liquid-liquid extraction followed by LC-MS/MS analysis

French ''vin jaune''

Vin jaune ''Vin jaune'' ( French for "yellow wine") is a special and characteristic type of white wine made in the Jura region in eastern France. It is similar to dry fino Sherry and gets its character from being matured in a barrel under a film of y ...

'' is marked by the formation of sotolon from α-ketobutyric acid.

References

{{Reflist Flavors Furanones Enols

French ''vin jaune''

See also

References