Urishiol

Urushiol
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

Urushiol /ʊˈruːʃi.ɒl/ is an oily organic compound with allergic properties found in plants of the family Anacardiaceae, especially Toxicodendron spp. (e.g., poison oak, Lacquer Tree, poison ivy, poison sumac) and also in parts of the mango tree.

In most individuals, urushiol causes an allergic skin rash on contact, known as urushiol-induced contact dermatitis.

The name urushiol is derived from the Japanese word for the lacquer tree, Toxicodendron vernicifluum (漆, urushi). 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, Korean and Japanese lacquerware.

Urushiol is a pale-yellow liquid with a specific gravity of 0.968 and a boiling point of 200 °C (392 °F). It is soluble in ethanol, diethyl ether, and benzene.