Betulin
Betulin is an abundant, naturally occurring triterpene. It is commonly isolated from the bark of birch trees. It forms up to 30% of the dry weight of silver birch bark. It is also found in birch sap. "Inonotus obliquus" and red alder also contain betulin.

The compound in the bark gives the tree its white color which appears to protect the tree from mid-winter overheating by the sun. As a result, birches are some of the northernmost occurring deciduous trees. It can be converted to betulinic acid (the alcohol group replaced by a carboxylic acid group), which is biologically more active than betulin itself.
Q2915788
triterpene
Concept
Q184453
bark
Concept
Q25243
birch
Concept
Q156895
silver birch
Concept
Q865598
birch sap
Concept
Q1956937
Inonotus obliquus
Concept
Q1818806
red alder
Concept
Q384111
betulinic acid
Concept
Q156
alcohol
Concept
Q134856
carboxylic acid
Concept
Q419726
Betulin
Concept
+30^^http://www.w3.org/2001/XMLSchema#decimal
30
NUMBER
found in taxon
found in taxon
instance of