
Betulin (lup-20(29)-ene-3β,28-diol) is an abundant, naturally occurring triterpene. It is commonly isolated from the bark of birch trees and forms up to 30% of the dry weight of the extractive. The purpose of the compound in the bark is not known. It can be converted to betulinic acid (the alcohol group replaced by a carboxylic acid group), which...
Found on
http://en.wikipedia.org/wiki/Betulin

• (n.) A substance of a resinous nature, obtained from the outer bark of the common European birch (Betula alba), or from the tar prepared therefrom; -- called also birch camphor.
Found on
http://thinkexist.com/dictionary/meaning/betulin/
Bet'u·lin noun [ Latin
betula birch tree.]
(Chemistry) A substance of a resinous nature, obtained from the outer bark of the common European birch (
Betula alba ), or from the tar prepared therefrom; -- called also
birch camphor .
Watts. Found on
http://www.encyclo.co.uk/webster/B/44
No exact match found.