Sotolon

Structural formula
	( R ) -Sotolon (left) and ( S ) -Sotolon (right)
General
Non-proprietary name	Sotolon
other names	3-hydroxy-4,5-dimethylfuran-2 (5 H ) -one ( IUPAC ); 2-Hydroxy-3-methyl-2-penten-4-olide;
Molecular formula	C 6 H 8 O 3
External identifiers / databases
EC number	249-136-4
ECHA InfoCard	100.044.655
PubChem	62835
Wikidata	Q421173
properties
Molar mass	128.13 g mol −1
Physical state	firmly
density	1.049 g cm −3
Melting point	26-29 ° C
boiling point	184 ° C
safety instructions
GHS labeling of hazardous substances	no GHS pictograms
	no GHS pictograms
H and P phrases	H: no H-phrases
	P: no P-phrases
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Sotolon is a heterocyclic compound with the structure of an intramolecular carboxylic acid ester ( lactone ). The substance, which is liquid at room temperature, is a strong aromatic substance that smells of maple syrup , caramel or burnt sugar in low concentrations , and of curry , lovage ( Levisticum officinale ) or fenugreek ( Trigonella foenum-graecum ) in high concentrations .

Substance properties

Sotolon is a white to slightly yellow solid or a colorless to slightly yellow liquid. The odor perception threshold of the substance is a few µg / kg.

Occurrence

Lovage

Sotolon is the main odor component in the two plants lovage and fenugreek and has a significant share in the aromas of maple syrup. Roasted Virginian tobacco , matured Madeira wines and port wines that are decades old , sake and other rice wines contain Sotolon and contribute to the aroma. Sotolon has also been found in citrus-containing soft drinks, but there it is an extraneous aroma that develops non-enzymatically from ethanol and ascorbic acid during storage .

Biological importance

Eating large amounts of foods and plants containing sotolon, such as fenugreek, can cause urine and sweat to temporarily take on the odor of maple syrup, as sotolon is secreted from the body relatively unchanged . People who suffer from the autosomal recessive inherited maple syrup disease only have defective 2-keto acid dehydrogenase complexes (BCKAD complex), which leads to an impaired breakdown of the amino acids leucine (Leu), isoleucine (Ile) and valine (Val) . These accumulate in the blood, as does sotolon, which comes from the leucine intermediate metabolism and is detectable in the patient's urine, which smells of maple syrup.

Others

On the night of June 11, 2013, four kilograms of Sotolon were released in a chemical plant of the Silesia company in Neuss-Allerheiligen through a 120 m high chimney. As part of a distillation process, the aromatic substance Sotolon was released. When the substance came into contact with a hot surface, it then evaporated. This meant that in the mornings in the greater Cologne area and later also in Düsseldorf, residents perceived a pronounced smell of soup or “ Maggi ”. The city fire brigade used six measuring vehicles and two control vehicles to investigate the cause.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g data sheet 4,5-dimethyl-3-hydroxy-2,5-dihydrofuran-2-ones from Sigma-Aldrich , accessed on May 9, 2017 ( PDF ).
^ ^A ^b F. Podebrad, M. Heil, S. Reichert, A. Mosandl, AC Sewell, H. Bohles: 4,5-dimethyl-3-hydroxy-2 [5 H ] -furanone (sotolone) - the odor of maple syrup urine disease. In: J. Inherit. Metab. Dis. 22, 1999, pp. 107-114. PMID 10234605 .
↑ Hans-Dieter Belitz : Textbook of food chemistry . Springer, Berlin 2008, ISBN 978-3-540-73201-3 .
↑ JS Câmara, JC Marques, MA Alves, AC Silva Ferreira: 3-Hydroxy-4,5-dimethyl-2 (5 H ) -furanone levels in fortified Madeira wines: relationship to sugar content. In: J. Agric. Food Chem. 52, 2004, pp. 6765-6769. PMID 15506814 .
^ AC Silva Ferreira, JC Barbe, A. Bertrand: 3-Hydroxy-4,5-dimethyl-2 (5 H ) -furanone: a key odorant of the typical aroma of oxidative aged port wine. In: J. Agric. Food Chem. 51, 2003, pp. 4356-4363. PMID 12848510 .
↑ T. König, B. Gutsche, M. Hartl, R. Hübscher, P. Schreier, W. Schwab: 3-Hydroxy-4,5-dimethyl-2 (5 H ) -furanone (Sotolon) causing an off-flavor : elucidation of its formation pathways during storage of citrus soft drinks. In: J. Agric. Food Chem. 47, 1999, pp. 3288-3291. PMID 10552647 .
↑ ^a ^b Chronology of the 'Maggikalypse' In: Kölner Stadtanzeiger. 11th of June 2013.
↑ Maggi-Duftwolke: The statement of the aroma manufacturer in full. on: express.de

[Sigma-1] ↑ ^a ^b ^c ^d ^e ^f ^g data sheet 4,5-dimethyl-3-hydroxy-2,5-dihydrofuran-2-ones from Sigma-Aldrich , accessed on May 9, 2017 ( PDF ).

[mosandl-2] A ^b F. Podebrad, M. Heil, S. Reichert, A. Mosandl, AC Sewell, H. Bohles: 4,5-dimethyl-3-hydroxy-2 [5 H ] -furanone (sotolone) - the odor of maple syrup urine disease. In: J. Inherit. Metab. Dis. 22, 1999, pp. 107-114. PMID 10234605 .

[3] Hans-Dieter Belitz : Textbook of food chemistry . Springer, Berlin 2008, ISBN 978-3-540-73201-3 .

[camara-4] JS Câmara, JC Marques, MA Alves, AC Silva Ferreira: 3-Hydroxy-4,5-dimethyl-2 (5 H ) -furanone levels in fortified Madeira wines: relationship to sugar content. In: J. Agric. Food Chem. 52, 2004, pp. 6765-6769. PMID 15506814 .

[silva-5] AC Silva Ferreira, JC Barbe, A. Bertrand: 3-Hydroxy-4,5-dimethyl-2 (5 H ) -furanone: a key odorant of the typical aroma of oxidative aged port wine. In: J. Agric. Food Chem. 51, 2003, pp. 4356-4363. PMID 12848510 .

[König-6] T. König, B. Gutsche, M. Hartl, R. Hübscher, P. Schreier, W. Schwab: 3-Hydroxy-4,5-dimethyl-2 (5 H ) -furanone (Sotolon) causing an off-flavor : elucidation of its formation pathways during storage of citrus soft drinks. In: J. Agric. Food Chem. 47, 1999, pp. 3288-3291. PMID 10552647 .

[ksta-7] Chronology of the 'Maggikalypse' In: Kölner Stadtanzeiger. 11th of June 2013.

[8] Maggi-Duftwolke: The statement of the aroma manufacturer in full. on: express.de