Decenoic acid
Decenoic acid is any mono-carboxylic acid with an unbranched chain of ten carbons connected by eight single bonds and one double bond; that is, a chemical compound with formula ––––H, where k is between 0 and 7 inclusive.
There are fifteen of these compounds, that can be identified by the position k+2 of the double bond and the configuration of the single bonds adjacent to it.
Decenoic acids are technically mono-unsaturated fatty acids, although they are relatively rare in nature.
Examples
Free acids and esters
Some isomers that have received attention are- cis-2-decenoic acid or -dec-2-enoic acid. Produced by Pseudomonas aeruginosa, inhibits biofilm formation.
- trans-2-decenoic acid or -dec-2-enoic acid. Flavoring agent ; Density: 0.92-0.93 25 °C. Refractive Index: ~1.46 at 20.00 °C. MP: 12 °C BP: 161-162 °C. at 15.00 torr, 278-279 °C. at 1 atm. Odor described as "fresh, fruity, slightly oily and waxy". Stimulates nerve cell regeneration and biofilm disintegration. Excreted by the caries bacterium Streptococcus mutans and inhibits growth of the fungus Candida albicans.
- * ethyl trans-2-decenoate Flavoring agent. BP: ~134 °C. at 20.00 torr, 140 °C. at 30.00 torr. Odor described as "green, fruity, waxy." "peely citrus".
- cis-3-decenoic acid or -dec-3-enoic acid. The female sex pheromone of the furniture carpet beetle Anthrenus flavipes. Odor deascribed as "fatty".
- trans-3-decenoic acid Occurs in some natural extracts.
- cis-4-decenoic acid or -dec-4-enoic acid. A metabolite found in human plasma in certain pathologies. Odor described as "fatty, green".
- * ethyl cis-4-decenoate Flavoring agent. Density: 0.883 at 20 °C. Refractive Index: 1.438 at 20 °C. BP: 128 °C. at 30 torr, 236-237 °C. at 1 atm.
- trans-4-decenoic acid or -dec-4-enoic acid. Result of reacting 1‐octene and manganese(III) acetate.
- * ethyl trans-4-decenoate Density: ~0.876 at 25.00 °C. Refractive Index: ~1.437 at 20.00 °C. BP: 72.00 °C. at 0.10 torr. Odor described as "green, fruity, waxy, cognac".
- cis-5-decenoic acid Odor described as "fatty, green".
- trans-5-decenoic acid Odor described as "milky, fatty".
- caproleic acid, 9-decenoic acid, or dec-9-enoic acid. Small amounts in goat and cow milk, and oils of Sapium sebiferum and Litsea cubeba. Traces also in beer, wine, clams, Parmesan cheese and snails. Broad-spectrum antimicrobial. Flavoring agent. Density: ~0.9 at 20.00 °C. BP: ~270 °C at 1 atm, 130-135 °C at 1-3 torr, 95 °C at 0.1 torr. Refractive index nD20: 1.4488. Irritating to skin. Used as flavouring agent. Odor described as milky, waxy, green, fatty, soapy, creamy, cheesy".
- * ethyl caproleate, 9-decenoic acid ethyl ester used as flavoring agent. Odor described as "fruity". Density: ~0.878 at 25.00 °C. Refractive Index: ~1.44 at 20.00 °C. BP: 249-250 °C. at 1 atm.
Unspecified isomers and mixtures
- From 3-decenoic acid:
- * butyl 2-decenoate, isomer unspecified, is a flavoring agent with odor described as "fruity, green, fatty, coconut, walnut". Density: 0.87-0.88 at 25.00 °C. Refractive Index: ~1.45 at 20.00 °C. BP: 290-291 °C. at 1 atm. Flavouring agent.
- * methyl 2-decenoate, isomer unspecified, is used as flavouring ingredient, with odor described as "mushroom".
- 4-decenoic acid, unspecified isomer, is said to occur in hops and beer. It is a flavoring agent, with odor described as "fruity". Density: ~0.92 at 20.00 °C. Refractive Index: ~1.15 at 20.00 °C. BP: 97.00 to 98.00 °C. at 0.30 torr. It is listed as "no concern" food additive by the FAO/WHO JECFA.
- A mixture of 5-decenoic and 6-decenoic acids, with the trade name "milk lactone", is allowed in the US as generally recognized as safe flavorings, such as in imitation dairy products with common name "milk lactone" for their milk-like aroma.
Derivatives
- 4-Hydroxy-4-methyl-cis-7-decenoic acid. Its gamma lactone is a flavoring agent.
- 5-hydroxy-7-decenoic acid. Its lactone was identified as a significant component of the aroma of black tea, reminiscent of flowers and dried fruit, and is a flavoring agent.
- 9-hydroxy-trans-2-decenoic acid. Another queen bee pheromone.
- 9-oxo-cis-2-decenoic acid. Is converted to the trans isomer by light and may function as inhibitor of bee colony settlement.
- 9-oxo-trans-2-decenoic acid.A pheromone produced by queen bees.
- Queen [bee acid|10-hydroxy-trans-2-decenoic acid], "queen bee acid". The main fatty acid in bee's royal jelly. Characteristic odor.
- 9-Oxodecenoic acid Queen substance
- 10-oxo-7-hydroxy-trans-8-decenoic acid. Formed by plants in response to mechanical trauma.
- 10-oxo-trans-8-decenoic acid. A metabolite of the mushrooms Agaricus bisporus and Pleurotus pulmonarius. Possibly a fungal growth hormone.