Chemical Properties
viscous yellow liquid or crystals with a citrus odour;
Definition
ChEBI: A sesquiterpenoid that is 4,4a,5,6,7,8-hexahydronaphthalen-2(3H)-one which is substituted by methyl groups at positions 4 and 4a, and by an isopropenyl group at position 6 (the 4R,4aS,6R
stereoisomer).
Description
Nootkatone has a pleasant taste. It may be prepared by oxidation of valencene (a sesquiterpene) with tertiary butyl chromate.
Occurrence
Reported found in grapefruit oil and juice; traces are also reported found in the oils of bergamot, lemon, lime,
orange and tangerine; also reported formed in canned orange juice on storage.
Uses
Nootkatone is an effective repellent/insecticide against mosquitos, and may repel bed bugs, head lice and other insects. Nootkatone in spray form has been shown as an effective repellent/insecticide against deer ticks and lone star ticks.
Preparation
By oxidation of valencene (a sesquiterpene) with tertiary butyl chromate.
Aroma threshold values
Detection: 170 to 800 ppb
Taste threshold values
Taste characteristics at 20 ppm: grapefruit, citrus, orange and butter.
General Description
(+)-nootkatone, a bicyclic conjugated sesquiterpene ketone with a grapefruit-like flavor, is commonly used in fragrance, food, cosmetics and pharmaceutical industry. It can be synthesized from (+)-valencene via biotransformation. (+)-nootkatone is the active ingredient responsible for the antiplatelet effect of Cyperus rotundus, a well-known oriental traditional medicine. It also shows promising efficacy against Staphylococcus aureus biofilms.
