Kahweol
| Structural formula | ||||||||||
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| General | ||||||||||
| Surname | Kahweol | |||||||||
| other names |
1,2-dehydrocafestol |
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| Molecular formula | C 20 H 26 O 3 | |||||||||
| Brief description |
rod-shaped crystals |
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| properties | ||||||||||
| Molar mass | 314.42 g mol −1 | |||||||||
| Physical state |
firmly |
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| Melting point |
88-90 ° C |
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| solubility |
soluble in acetone |
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| safety instructions | ||||||||||
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | ||||||||||
Kahweol , also 1,2-dehydrocafestol, is a chemical compound from the group of diterpenes that occurs naturally in the fruits of the coffee plant . Coffea arabica varieties contain around 3 g / kg in the dry matter, Coffea robusta beans sometimes only contain traces, a maximum of 2 g / kg. The terpene is present in the fruit as an ester with fatty acids , usually as a palmitate or behenic acid ester. Kahweol is also formed during roasting from the cafestol contained in higher quantities , partly decomposed, and is also found in coffee infusions .
Structure and properties
The chemical structure of kahweol can be described as a derivative of kauran , a tetracyclophytan , with a fused furan ring. Kahweol is a strong oxidizing agent that can split off carbon monoxide and dioxide when heated . It is extremely sensitive to acids .
Use and biological effect
Coffee bean oil , which contains 15% kahweol and cafestol, was used as a sunscreen . Both substances showed anti-inflammatory, anti- genotoxic and anti- carcinogenic properties; in rats they prevented the formation of breast carcinomas , in golden hamsters various tumors were inhibited by up to 40%. The effect is attributed to an activation of glutathione-S-transferase . Analogous to the related cafestol, kahweol also inhibits the enzymes cholesterol-7-hydroxylase and sterol-27-hydroxylase in the hepatocytes , which are necessary for the breakdown of cholesterol into bile acids , and thus indirectly increases the cholesterol level .
Individual evidence
- ↑ a b c d e f g National Toxicology Program (NTP): Cafestol (CASRN 469-83-0) and Kahweol (CASRN 6894-43-5) - Review of Toxicological Literature. ( Memento from May 29, 2016 in the Internet Archive ) (PDF; 890 kB), October 1999.
- ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
- ^ A b Robert Hegnauer: Chemotaxonomy of plants: An overview of the distribution and the systematic importance of plant substances. Volume 21, Birkhäuser, 1973, ISBN 978-3-7643-0667-0 , p. 169.
- ^ Wissenschaft-Online-Lexika: Entry on Cafestol in the Lexicon of Nutrition. Retrieved November 5, 2009.
- ^ Gene A. Spiller: Caffeine. CRC Press, 1998, ISBN 978-0-8493-2647-9 . P. 311.