Nootkatone

  • 4α ,5 -dimethyl- α 1,2,3,4,4 ,5,6,7 - octahydro -7 -keto -3- isopropenylnaphthalen
  • ( )- Nootkatone

Colorless solid

Fixed

1.00 g · cm -3

32-33 ° C

125 ° C ( 67 Pa)

Partially in water

Template: Infobox chemical / molecular formula search available

Nootkatone is a bicyclic sesquiterpene and comes as a specific flavor in many Citrus species. Natural nootkatone is a high-priced natural flavoring substance and finds its main use as a flavoring in soft drinks and as a pharmaceutical. The isolation from natural sources is very expensive, since the content of this substance at only about 0.01 % in mandarin and orange oil and about 0.5% in grapefruit oil.

Properties

Nootkatone is a crystalline, colorless solid, above the melting point of 32-33 ° C, a viscous yellow liquid. The molecule has two chiral centers. The two enantiomers differ greatly in their flavor intensity and flavor property:

  • ( )- Nootkatone is the smell of grapefruit carrier; the odor threshold is 0.001 ppm
  • (-)- Nootkatone has a wood-like odor; the odor threshold is 1 ppm.

The market price for natural ( )- nootkatone is 4000-6500 € / kg.

Technical production of nootkatone from valencene

There are various methods for the preparation of nootkatone. Most go from bicyclic sesquiterpene ( ) - from valencene, which is the main component of the essential oil of Valencia orange and grapefruit (besides limonene, myrcene and linalool and other terpenoids secondary components ). Valencene is cheap and available in large quantities.

Chemical

  • Photooxygenation in the presence of copper salts,
  • Metal catalytic transformation
  • Oxidation with tert- butyl chromate butylperacetate or tert-, butyl chromate and valencene
  • Synthesis of cyclohexene or cyclohexadiene derivatives

Biotechnological processes

In contrast to the produced by chemical processes that nootkatone bioengineered can be described as natural, and so may be used as a natural flavoring substance.

These methods include whole cell biotransformation by

  • Fungi such as Chaetomium globosum, Pleurotus sapidus, Botryosphaeria Rhodina, Phanerochaete chrysosporim, Botryosphaeria dothide, Trametes spec.
  • Bacteria such as Enterobacter sp., Rodococcus KSM- 5706
  • Plants such as Gynostemma pentaphyllum

Also about other biotechnological processes nootkatone can be synthesized:

  • Enzymatic methods ( isolated enzyme )
  • Laccase for example, from Trametes versicolor
  • Lignin peroxidase
  • P450 monooxygenases
CAS registry number Journal of Agricultural and Food Chemistry
607421
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