Urushiol
From Free net encyclopedia
For information on urushiol poisoning, see Urushiol-induced contact dermatitis.
Urushiol (you-ROO-shee-ol) is an oil found in plants of the Family Anacardiaceae, especially Toxicodendron spp. (e.g. poison oak, poison-ivy, and poison sumac). It causes an allergic skin rash on contact, known as urushiol-induced contact dermatitis. The name comes from urushi, a lacquer produced in Japan from the sap of kiurushi trees (Toxicodendron vernicifluum).
Urushiol is a yellow liquid with a boiling point of 200-210 °C. It is soluble partially in alcohol and ether, but nearly insoluble in water. Chemically, urushiol is mixture of several closely related organic compounds. Each consists of a catechol substituted with an alkyl chain that has 15 or 17 carbon atoms. The alkyl group may be saturated or unsaturated, urushiol oil is a mixture of the saturated and unsaturated urushiol molecules. The exact mixture depends on the species of the plant. For example, poison oak urushiol contains mostly catechols with C17 side chains, but poison ivy and poison sumac contain mostly catechols with C15 side chains. The allergic reaction is dependent on the degree of unsaturation of the alkyl chain. Less than half of the general population reacts with the saturated urushiol alone, but over 90% react with urushiol containing at least two degrees of unsaturation (double bonds).
R = (CH2)14CH3 or
R = (CH2)7CH=CH(CH2)5CH3 or
R = (CH2)7CH=CHCH2CH=CH(CH2)2CH3 or
R = (CH2)7CH=CHCH2CH=CHCH=CHCH3 or
R = (CH2)7CH=CHCH2CH=CHCH2CH=CH2 and others.
See also
- Burow's solution, for treating the toxin
- Poison-ivy
- Western Poison-oak
- Toxin
External links
- Poison Oak at Wayne's Word
- The Poison Ivy Tutorial