A toxic substance present in the resin or on the surface of plants of the genus Rhus, including poison ivy and the lacquer tree, from which a black Japanese lacquer is obtained.
[Japanese urushi, lacquer + -OL1.]
urushiol
Dictionary:
u·ru·shi·ol (ʊ-rū'shē-ôl', -ōl', -ŏl')  |
n.
A toxic substance present in the resin or on the surface of plants of the genus Rhus, including poison ivy and the lacquer tree, from which a black Japanese lacquer is obtained.
A toxic substance present in the resin or on the surface of plants of the genus Rhus, including poison ivy and the lacquer tree, from which a black Japanese lacquer is obtained.
| 5min Related Video: urushiol |
| Medical Dictionary: u·ru·shi·ol |
(ʊ-rū'shē-ôl', -ōl')
n.
n.
A toxic substance constituting the active allergen of the irritant oil present in poison ivy, poison oak, and poison sumac.
| Veterinary Dictionary: urushiol |
The toxic irritant principle of poison ivy and various related plants.
| Wikipedia: Urushiol |
- For information on urushiol poisoning, see Urushiol-induced contact dermatitis.
Urushiol (pronounced /ʊˈruːʃiɒl/) is an organic oil toxin 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,[1] known as urushiol-induced contact dermatitis. The name comes from the Japanese word urushi, which denotes a lacquer produced in East Asia from the sap of kiurushi trees (Lacquer Tree). The oxidation and polymerization of urushiol in the tree's sap in the presence of moisture allows it to form a hard lacquer, which is used to produce traditional Chinese and Japanese lacquerwares.
Urushiol is a yellow liquid with a boiling point of 200-210 °C. It is miscible in alcohol and ether, but nearly insoluble in water. Urushiol is a 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 saturated and unsaturated molecules. The mixture varies with the vegetative species. Whereas Western poison oak urushiol contains chiefly catechols with C17 side-chains,[2] poison ivy and poison sumac yield 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).
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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
- Urushiol-induced contact dermatitis
- Burow's solution, for treating the toxin
- Bentoquatam, a barrier creme
- Hapten
- Ginko biloba
- Poison ivy
- Western Poison-oak
- Mango
- Pistachio
- Anti-itch drug
- Anacardic acid
References
- ^ Buck Tilton (2004) Wilderness First Responder: How to Recognize, Treat, and Prevent Emergencies in the Backcountry, Globe Pequot, 320 pages ISBN 0762728019
- ^ C. Michael Hogan (2008) Western poison-oak: Toxicodendron diversilobum, GlobalTwitcher, ed. Nicklas Stromberg [1]
External links
- Poison Oak at Wayne's Word
- The Poison Ivy Tutorial
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 | Poison Ivy, Oak, and Sumac |
| poison ivy (plant) |
| Why does poison ivy give people rashes? (kids) |
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 | Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved. Read more |
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| Medical Dictionary. The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Read more |
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| Veterinary Dictionary. Saunders Comprehensive Veterinary Dictionary 3rd Edition. Copyright © 2007 by D.C. Blood, V.P. Studdert and C.C. Gay, Elsevier. All rights reserved. Read more |
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| Wikipedia. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article "Urushiol". Read more |
