Isopropyl methoxypyrazine

Isopropyl methoxy pyrazine

Chemical structure of isopropyl methoxy pyrazine
Names
Preferred IUPAC name 2-Methoxy-3-(propan-2-yl)pyrazine
Other names 2-Isopropyl-3-methoxypyrazine
Identifiers
CAS Number	25773-40-4^Y
3D model (JSmol)	Interactive image
ChemSpider	30649^N
ECHA InfoCard	100.042.946
PubChemCID	33166
UNII	1FL7L111A6^Y
CompTox Dashboard(EPA)	DTXSID4067147
InChI InChI=1S/C8H12N2O/c1-6(2)7-8(11-3)10-5-4-9-7/h4-6H,1-3H3^N Key: NTOPKICPEQUPPH-UHFFFAOYSA-N^N InChI=1/C8H12N2O/c1-6(2)7-8(11-3)10-5-4-9-7/h4-6H,1-3H3 Key: NTOPKICPEQUPPH-UHFFFAOYAE
SMILES CC(C)C1=NC=CN=C1OC
Properties
Chemical formula	C8H12N2O
Molar mass	152.19 g/mol
Hazards
GHS labelling:[1]
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P302+P352, P305+P351+P338
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is ^YN ?) Infobox references

Isopropyl methoxypyrazine (IPMP) is a methoxypyrazine, a class of chemical compounds that produce odors. The odor is rather undesirable and is produced by the Asian lady beetle or by the actinomycete Streptomyces sp, and yeast, specifically Saccharomyces cerevisiae. ^[2] It can be detected by human taste at concentrations of as low as 2 nanograms per litre.^[3]

Presence in wine grapes

The odor of IPMP tends to be undesirable in the case of certain wines.^[4]

Cabernet Sauvignon has high levels of methoxypyrazines.^[5][6] Two methoxypyrazine compounds, 3-isobutyl-2-methoxypyrazine (IBMP) and 3-isopropyl-2-methoxypyrazine, are considered to be important determinants of green flavours in Sauvignon blanc wines.^[7]

Presence in coffee

IPMP is also an important flavour compound in coffee and is responsible for causing an off-taste called "potato taste" in East African coffee.^[8] The insects Antestiopsis are also implicated in causing the taste.^[9]

See also

• Alkylpyrazines

References

1. GHS: sigma-aldrich 243132Archived 2024-05-01 at the Wayback Machine
2. Three highly odorous metabolites from an actinomycete: 2-Isopropyl-3-methoxy-pyrazine, methylisoborneol, and geosmin. Nancy N. Gerber, Journal of Chemical Ecology, Volume 3, Number 4, pp. 475-482, doi:10.1007/BF00988190
3. Cristina Sala; Olga Busto; Josep Guasch; Fernando Zamora. Factors affecting the presence of 3-alkyl-2- methoxypyrazines in grapes and wines. A review(PDF) (Report). Archived(PDF) from the original on 2016-03-03. Retrieved 2012-04-01.
4. "Trace flavour components of grapes". Archived from the original on 2012-02-06. Retrieved 2011-12-24.
5. winepros.com.au Oxford Companion to WinemethoxypyrazinesArchived 2012-02-29 at the Wayback Machine
6. Oz Clarke Encyclopedia of Grapes pg 223 Harcourt Books 2001 ISBN 0-15-100714-4
7. Marais, J., Hunter, J.J., & Haasbroek, P.D. (1999). Effect of microclimate, season and region on Sauvignon blanc grape composition and wine quality. South African Journal of Enology and Viticulture, 20, 19-30.
8. Czerny, M.; Grosch, W. (2000). "Potent Odorants of Raw Arabica Coffee. Their Changes during Roasting". Journal of Agricultural and Food Chemistry. 48 (3): 868–872. Bibcode:2000JAFC...48..868C. doi:10.1021/jf990609n. PMID 10725165.
9. B. Bouyjou; B. Decazy; G. Fourny. "L'élimination du " goût de pomme de terre " dans le café Arabica du Burundi" [Removing the "potato taste" from Burundian Arabica]. Plantations, Recherche, Développement (in French). 6 (2): 107–115. Archived from the original on 2012-03-11. Retrieved 2012-04-01.