Sotolon (also known as sotolone) is a
butenolide
Butenolides are a class of lactones with a four-carbon heterocycle, heterocyclic ring structure.Joule JA, Mills K. (2000). Heterocyclic Chemistry 4th ed. Blackwell Science Publishing: Oxford, UK They are sometimes considered redox, oxidized deri ...
lactone
Lactones are cyclic carboxylic esters. They are derived from the corresponding hydroxycarboxylic acids by esterification. They can be saturated or unsaturated.
Lactones are formed by lactonization, the intramolecular esterification of the corresp ...
and an extremely potent
aroma compound
An aroma compound, also known as an odorant, aroma, fragrance, flavoring or flavor, 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 sufficien ...
, with the typical smell of
fenugreek
Fenugreek (; ''Trigonella foenum-graecum'') is an annual plant in the family Fabaceae, with leaves consisting of three small Glossary_of_leaf_morphology#Leaf_and_leaflet_shapes, obovate to oblong leaflets. It is cultivated worldwide as a semiar ...
or
curry
Curry is a dish with a sauce or gravy seasoned with spices, mainly derived from the interchange of Indian cuisine with European taste in food, starting with the Portuguese, followed by the Dutch and British, and then thoroughly internatio ...
at high concentrations and
maple syrup
Maple syrup is a sweet syrup made from the sap of maple trees. In cold climates, these trees store starch in their trunks and roots before winter; the starch is then converted to sugar that rises in the sap in late winter and early spring. Ma ...
,
caramel
Caramel ( or ) is a range of food ingredients made by heating sugars to high temperatures. It is used as a flavoring in puddings and desserts, as a filling in bonbons or candy bars, as a topping for ice cream and custard, and as a colorant ...
, or burnt sugar at lower concentrations. Sotolon is the major aroma and flavor component of fenugreek seed and
lovage, and is one of several aromatic and flavor components of
artificial maple syrup. It is also present in
molasses
Molasses () is a viscous byproduct, principally obtained from the refining of sugarcane or sugar beet juice into sugar. Molasses varies in the amount of sugar, the method of extraction, and the age of the plant. Sugarcane molasses is usuall ...
, aged
rum
Rum is a liquor made by fermenting and then distilling sugarcane molasses or sugarcane juice. The distillate, a clear liquid, is often aged in barrels of oak. Rum originated in the Caribbean in the 17th century, but today it is produced i ...
, aged
sake
Sake, , or saki, also referred to as Japanese rice wine, is an alcoholic beverage of Japanese origin made by fermenting rice that has been polished to remove the bran. Despite the name ''Japanese rice wine'', sake, and indeed any East Asi ...
and
white wine
White wine is a wine that is Fermentation in winemaking, fermented without undergoing the process of Maceration (wine), maceration, which involves prolonged contact between the juice with the grape skins, seeds, and pulp. The wine color, colou ...
,
flor sherry
Sherry ( ) is a fortified wine produced from white grapes grown around the city of Jerez de la Frontera in Andalusia, Spain. Sherry is a drink produced in a variety of styles made primarily from the Palomino grape, ranging from light versio ...
, roast tobacco, and dried fruiting bodies of the mushroom ''
Lactarius helvus''. 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 a rare, inherited metabolic disorder that affects the body's ability to metabolize amino acids due to a deficiency in the activity of the branched-chain alpha-ketoacid dehydrogenase (BCKAD) complex. It parti ...
, sotolon 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
Manhattan ( ) is the most densely populated and geographically smallest of the Boroughs of New York City, five boroughs of New York City. Coextensive with New York County, Manhattan is the County statistics of the United States#Smallest, larg ...
since 2005, with the source of the sotolon being a factory in New Jersey that processes the herb
fenugreek
Fenugreek (; ''Trigonella foenum-graecum'') is an annual plant in the family Fabaceae, with leaves consisting of three small Glossary_of_leaf_morphology#Leaf_and_leaflet_shapes, obovate to oblong leaflets. It is cultivated worldwide as a semiar ...
.
Sotolon was first isolated in 1975 from fenugreek. The compound was named in 1980 when it was found to be responsible for the flavor of raw cane sugar: means "raw sugar" in
Japanese and the
suffix
In linguistics, a suffix is an affix which is placed after the stem of a word. Common examples are case endings, which indicate the grammatical case of nouns and adjectives, and verb endings, which form the conjugation of verbs. Suffixes can ca ...
''-olon'' signifies that the molecule is an
enol
In organic chemistry, enols are a type of functional group or intermediate in organic chemistry containing a group with the formula (R = many substituents). The term ''enol'' is an abbreviation of ''alkenol'', a portmanteau deriving from "-ene ...
lactone
Lactones are cyclic carboxylic esters. They are derived from the corresponding hydroxycarboxylic acids by esterification. They can be saturated or unsaturated.
Lactones are formed by lactonization, the intramolecular esterification of the corresp ...
.
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 types of wines. This
chiral
Chirality () is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek language, Greek (''kheir''), "hand", a familiar chiral object.
An object or a system is ''chiral'' if it is dist ...
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
is a special and characteristic type of white wine made in the Jura (wine), 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 yeast (wine), yeast, known as the ...
'' is marked by the formation of sotolon from
α-ketobutyric acid.
See also
*
Candy cap (Lactarius mushroom species whose maple syrup aroma derives from quabalactone III, which hydrolyzes into sotolon).
References
{{Reflist
Flavors
Furanones
Enols