The molecule is a tetracyclic triterpenoid that is lanost-8-ene substituted by hydroxy groups at positions 3 and 25, a methylidene group at position 24 and an oxo group at position 7. Isolated from the whole plant of Silybum marianum, it exhibits inhibitory activity against chymotrypsin. It has a role as a metabolite and an EC 3.4.21.1 (chymotrypsin) inhibitor. It is a tetracyclic triterpenoid, a cyclic terpene ketone, a secondary alcohol and a tertiary alcohol.
(3S,5R,10S,13R,14R,17R)-3-hydroxy-17-[(2R)-6-hydroxy-6-methyl-5-methylideneheptan-2-yl]-4,4,10,13,14-pentamethyl-1,2,3,5,6,11,12,15,16,17-decahydrocyclopenta[a]phenanthren-7-one