Sotolon is a lactone

Lactone

In chemistry, a lactone is a cyclic ester which can be seen as the condensation product of an alcohol group -OH and a carboxylic acid group -COOH in the same molecule...

 and an extremely powerful aroma compound

Aroma compound

An aroma compound, also known as odorant, aroma, fragrance or flavor, is a chemical compound that has a smell or odor...

, with the typical smell of fenugreek

Fenugreek

Fenugreek is a plant in the family Fabaceae. Fenugreek is used both as a herb and as a spice . The leaves and sprouts are also eaten as vegetables...

 or curry

Curry

Curry is a generic description used throughout Western culture to describe a variety of dishes from Indian, Pakistani, Bangladeshi, Sri Lankan, Thai or other Southeast Asian cuisines...

 at high concentrations and maple syrup

Maple syrup

Maple syrup is a syrup usually made from the xylem sap of sugar maple, red maple, or black maple trees, although it can also be made from other maple species such as the bigleaf maple. In cold climates, these trees store starch in their trunks and roots before the winter; the starch is then...

, caramel

Caramel

Caramel is a beige to dark-brown confection made by heating any of a variety of sugars. It is used as a flavoring in puddings and desserts, as a filling in bonbons, and as a topping for ice cream, custard and coffee....

, or burnt sugar at lower concentrations. Sotolon is the major aroma and flavor component of fenugreek seed and lovage

Lovage

Lovage is a tall perennial plant, the sole species in the genus Levisticum, in the family Apiaceae, subfamily Apioideae, tribe Apieae.-Distribution:...

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

Molasses

Molasses is a viscous by-product of the processing of sugar cane, grapes or sugar beets into sugar. The word molasses comes from the Portuguese word melaço, which ultimately comes from mel, the Latin word for "honey". The quality of molasses depends on the maturity of the sugar cane or sugar beet,...

, aged rum

Rum

Rum is a distilled alcoholic beverage made from sugarcane by-products such as molasses, or directly from sugarcane juice, by a process of fermentation and distillation. The distillate, a clear liquid, is then usually aged in oak barrels...

, aged sake and white wine, flor

Flor

Flor is a winemaking term referring to a film of yeast on the surface of wine and which is important in the manufacture of certain styles of sherry. The flor is formed naturally under certain winemaking conditions, from indigenous yeasts found in the region of Andalucía in southern Spain...

 sherry

Sherry

Sherry is a fortified wine made from white grapes that are grown near the town of Jerez , Spain. In Spanish, it is called vino de Jerez....

, roast tobacco, and dried fruiting bodies of the mushroom Lactarius helvus

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. Mushrooms are pale brown-grey or beige in colour and funnel-shaped, with...

. 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

Maple syrup urine disease , also called branched-chain ketoaciduria, is an autosomal recessive metabolic disorder affecting branched-chain amino acids. It is one type of organic acidemia...

, it is spontaneously produced in their bodies and excreted it 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 in French vin jaune

Vin jaune

Vin jaune

Vin jaune is a special and characteristic type of white wine made in the Jura wine 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 yeast, known as the voile, on the wine's surface...

is marked by the formation of sotolon from alpha-ketobutyric acid

Alpha-Ketobutyric acid

α-Ketobutyric acid is a product of the lysis of cystathionine.It is also one of the degradation products of threonine.It can be converted to propionyl-CoA , and thus enter the citric acid cycle.- Conversion in sotolon in French Vin jaune :Vin jaune is marked by the formation of sotolon...

.