It forms up to 30% of the dry weight of silver birch bark.
As a result, birches are some of the northernmost occurring deciduous trees.
Betulin was discovered in 1788 by German-Russian chemist Johann Tobias Lowitz.
[4][5] Chemically, betulin is a triterpenoid of lupane structure.
It has a pentacyclic ring structure, and hydroxyl groups in positions C3 and C28.