Found in hot peppers, chilis (sometimes spelt chiles) but not in wasabi.

Pure capsaicin is almost guaranteed to give you respiratory arrest if you inhale it (it's a white powder). Thankfully, pure capsaicin only exists in pharmaceutical labs awaiting incorporation into various creams and lotions. Perhaps paradoxically, capsaicin preparations are quite useful as analgesic agents - they numb the pain sensation. Even so, the concentrations used are lower than 1% - dangerous stuff.

A measure of how concentrated capsaicin is in nature, have a look at http://www.flyingchilepepper.com/facts.html

8-methyl-n-vanillyl-6-nonenamide. A chemical which forms a large part of my diet. It has been found to have medicinal properties as a pain killer and is used in defensive Pepper Spray. It is the most potent and the most common of the Capsaicinoids

A friend once told me a story about two guys he knew. One of them was an early researcher of the properties of pure capsaicin. The other was a badass. The researcher always carried a bottle of pure capsaicin with him in order to flavor his foods. One time the researcher and the badass were eating breakfast together (with this friend of mine in attendance as well), and the researcher stuck the very tip of a toothpick into the capsaicin and gently waved it in the presence of his omelet. The badass asked what he was doing, and the researcher explained that he was using the vapor of the capsaicin to add some spice to his omelet.

The badass thought the researcher was a wuss, and took the bottle of capsaicin and poured some onto his own omelet.

Needless to say, the badass was shocked and humbled, and probably couldn't taste anything for a week.

Molecular Weight: 305.42
Empirical Formula: C₁₈H₂₇NO₃
Boiling Point: 210-220 degrees C
Melting Point: 65 degrees C
Soluble in: ethanol, ether, benzene, and petroleum ether

H3CO
    \_           O                    CH3
    / \          ||                   |
HO -   - C - N - C - (CH2)4 - C = C - C - CH3       
    \_/  |   |                |   |   |
         H2  H                H   H   H

Capsaicin is the chemical found in various hot plants that usually causes your tongue to burn. The hotness of capsaicin is measured in Scoville measurements, which is read as such:

• 0-100 - Sweet pepper varieties.


• 500-1000 - New Mexican peppers


• 1,000-1,500 - Espanola peppers


• 1,000-2,000 - Ancho Pasilla peppers


• 1,000-2,500 - Cascabel Cherry peppers


• 2,500-5,000 - Jalapeno Mirasol peppers


• 5,000-15,000 - Serrano peppers


• 15,000-30,000 - de Arbol peppers


• 30,000-50,000 - Cayenne Tabasco peppers


• 50,000-100,000 - Chiltepin peppers


• 100,000-350,000 - Scotch Bonnet Thai peppers


• 200,000 to 500,000 - Habanero peppers

16,000,000 Scoville Units is pure capsaicin

Cap*sa"i*cin (?), n. [From Capsicum.] Chem.

A colorless crystalline substance extracted from the Capsicum annuum, and giving off vapors of intense acridity.

 

© Webster 1913.