Capsaicin
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| Capsaicin | |
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| Chemical name | (E)-N-(4-hydroxy-3-methoxybenzyl)- 8-methylnon-6-enamide |
| Chemical formula | C18H27NO3 |
| Molecular mass | 305.41 g/mol |
| Melting point | 62 - 65 °C |
| CAS number | 404-86-4 |
| SMILES | CC(C)/C=C/CCCCC(NCC1=CC (OC)=C(O)C=C1)=O |
| Missing image Capsaicin_chemical_structure.png Chemical structure of capsaicin | |
The chemical compound capsaicin (8-methyl-N-vanillyl-6-nonenamide) is the active component of chile peppers (Capsicum). It is an irritant for mammals including humans and produces an illusion of burning in the mouth. Capsaicin and several related compounds are called capsaicinoids and are produced as a secondary metabolite by certain plants of the genus Capsicum (red peppers), probably as deterrants against herbivores. Birds are generally not sensitive to capsaicinoids. Pure capsaicin is a lipophilic colorless odorless crystalline to waxy compound.
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Capsaicinoids
Capsaicin is the main capsaicinoid in chile peppers, followed by dihydrocapsaicin. These two compounds are also about twice as hot as the minor capsaicinoids nordihydrocapsaicin, homodihydrocapsaicin, and homocapsaicin. Dilute solutions of pure capsaicinoids produced different types of pungency, however, these differences were not noted using more concentrated solutions.
| Capsaicinoid name | Abbrev. | Typicalrelativeamount | Scovilleheat units | Chemical structure |
| Capsaicin | C | 69% | 16,000,000 | Missing image Capsaicin_chemical_structure.png Chemical structure of capsaicin |
| Dihydrocapsaicin | DHC | 22% | 16,000,000 | Missing image Dihydrocapsaicin_chemical_structure.png Chemical structure of dihydrocapsaicin |
| Nordihydrocapsaicin | NDHC | 7% | 9,100,000 | Missing image Nordihydrocapsaicin_chemical_structure.png Chemical structure of nordihydrocapsaicin |
| Homodihydrocapsaicin | HDHC | 1% | 8,600,000 | Missing image Homodihydrocapsaicin_chemical_structure.png Chemical structure of homodihydrocapsaicin |
| Homocapsaicin | HC | 1% | 8,600,000 | Missing image Homocapsaicin_chemical_structure.png Chemical structure of homocapsaicin |
Uses
Food
Because of the burning sensation capsaicin is commonly used in food products to give them added spice or "heat" (piquancy). The degree of heat found within a food is measured on the Scoville scale. Typically the capsaicin is obtained by using chile peppers as the source. Another common source is hot sauces (which may contain pure capsaicin or chile peppers). These sources are preferred over pure capsaicin for reasons of safety resulting from the lower concentration.
A temporary way to relieve the burning sensation is to cool the mouth with cool food or beverages like tap water, ice cream, or milk. Whipped cream and granulated sugar also provide relief. Capsaicin is not soluble in water, but is in fat and alcohol. Thus when using water, the burning will return once the water is swallowed. A more effective solution is the consumption of fatty foods or beverages like buttered bread or milk because they will carry away the capsaicin molecules and thus reduce the source of the burning. Another remedy is to swish the mouth with hydrogen peroxide (but not swallow) or use a paper towel soaked with it to blot skin or lip irritations.
Medical
Capsaicin is used in topical ointments used to relieve the pain of peripheral neuropathy (for example post-herpetic neuralgia). The treatment typically involves the application of a topical anesthetic until the area is numb. Then the capsaicin is applied by a therapist wearing rubber gloves and a face mask. The capsaicin remains on the skin until the patient starts to feel the heat at which point it is promptly removed. The result appears to be that the nerves are overwhelmed from the burning sensation and are unable to report pain for an extended period of time.
Ointments and balms for the relief of aching muscles often contain capsaicin in the form of a chile oil extract, listed amongst the ingredients under such names as "capsic. oleo. res."
Probably the most famous user of medical capsaicin was baseball legend Sandy Koufax.
Non-lethal force
Capsaicin is also the active ingredient in the chemical riot control agent pepper spray. When the spray comes in contact with skin, especially eyes or mucous membranes it is very painful. Refer to the Scoville scale for a comparison of pepper spray to other sources of Capsaicin.
In large quantities, capsaicin can be a lethal poison. Symptoms of overdose include difficulty breathing, blue skin, and convulsions. While the large amount needed to kill an adult human being and the low concentration of capsaicin in chiles make accidental poisioning by chile consumption exceedingly unlikely, capsaicin has been implicated in some cases of infanticide in India.
Mechanism of action
The burning and painful sensations associated with capsaicin result from capsaicin's chemical interaction with sensory neurons. Capsaicin, as a member of the vanilloid family, binds to a receptor called the vanilloid receptor subtype 1 (VR1). First cloned in 1997, VR1 is an ion channel-type receptor. VR1, which can also be stimulated with heat and physical abrasion, permits positively-charged ions (i.e. cations) to pass through the cell membrane and into the cell from outside when activated. The resulting "depolarization" of the neuron stimulates it to signal the brain. By binding to the VR1 receptor, the capsaicin molecule produces the same effect that excessive heat or abrasive damage would cause, explaining why the spiciness of capsaicin is described as a burning sensation.
The VR1 ion channel has subsequently been shown to be a member of the superfamily of TRP ion channels, and as such is now referred to as TRPV1. There are a number of different TRP ion channels that have been shown to be sensitive to different ranges of temperature and probably are responsible for our range of temperature sensation. Thus, capsaicin does not actually cause a chemical burn; it causes only the sensation of one.
Capsaicin high
A euphoric sensation caused by the consumption of large quantities of capsaicin from capsaicin-laden foods. It's theorized that the pain induced by capsaicin causes the human body to release endorphins. Eventually, enough are released to create a sensation that is frequently compared to "runner's high."
External links
- 16,000,000 Scoville Heat Units chilli sauce launched (http://news.bbc.co.uk/2/hi/americas/4530739.stm)
- Capsaicin and Its Therapeutic Potential (http://sulcus.berkeley.edu/mcb/165_001/papers/manuscripts/_784.html)
- Molecule of the Month (http://www.chm.bris.ac.uk/motm/chilli/capsaicin.htm)
- Hotness scale of different capsaicinoids and pepper varieties (http://www.chilliworld.com/FactFile/Scoville_Scale.asp)
- European Commission (http://europa.eu.int/comm/food/fs/sc/scf/out120_en.pdf), opinion of the Scientific Committee on Food on capsaicin.de:Capsaicin
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