Methoxypyrazines

Chemical structure of isopropyl methoxy pyrazine (IPMP)

Methoxypyrazines are a class of chemical compounds that produce odors. The odors tend to be undesirable, as in the case of certain wines,^[1] or as in the case of the Asian Lady Beetle which produces isopropyl methoxy pyrazine (IPMP). They have also been identified as additives in cigarette manufacture. Detection thresholds are very low, typically near 2 parts per trillion (1 ng/L).^[1]

Examples of methoxypyrazines in wine grapes

Cabernet Sauvignon have high levels of methoxypyrazines.^[2][3] Two methoxypyrazine compounds, 3-isobutyl-2-methoxypyrazine (IBMP) and 3-isopropyl-2-methoxypyrazine (IPMP), are considered to be important determinants of green flavours in Sauvignon blanc wines.^[4]

See also

• Alkylpyrazines

References

1. ^ ^{a b} Trace flavour components of grapes
2. ^ winepros.com.au Oxford Companion to Wine methoxypyrazines
3. ^ Oz Clarke Encyclopedia of Grapes pg 223 Harcourt Books 2001 ISBN 0-15-100714-4
4. ^ 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.