Isopropyl methoxypyrazine (IPMP) is a
methoxypyrazine
Methoxypyrazines are a class of chemical compounds that produce odors. The odors tend to be undesirable, as in the case of certain wines, or as defensive chemicals used by insects such as ''Harmonia axyridis'' which produces isopropyl methoxy pyr ...
, 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. It can be detected by human taste at concentrations of as low as 2
nanogram
To help compare different ''Order of magnitude, orders of magnitude'', the following lists describe various ''mass'' levels between 10−67 kilogram, kg and 1052 kg. The least massive thing listed here is a graviton, and the most massive thi ...
s per litre.
Presence in wine grapes
The odor of IPMP tends to be undesirable in the case of certain wines.
has high levels of methoxypyrazines.
[Oz Clarke ''Encyclopedia of Grapes'' pg 223 Harcourt Books 2001 ] Two methoxypyrazine compounds,
3-isobutyl-2-methoxypyrazine
3-Isobutyl-2-methoxypyrazine (2-isobutyl-3-methoxypyrazine also known as Grindstaff pyrazine) is a methoxypyrazine that is very similar to isopropyl methoxy pyrazine except that the alkyl side-group contains an isobutyl group attached to the carbo ...
(IBMP) and 3-isopropyl-2-methoxypyrazine, are considered to be important determinants of green flavours in
Sauvignon blanc wines.
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.
The insects ''
Antestiopsis'' are also implicated in causing the taste.
See also
*
Alkylpyrazines
References
{{reflist
Pyrazines
Isopropyl compounds
Foul-smelling chemicals