Triterpenoids as novel natural inhibitors of human cathepsin L.Cathepsins L (catL) and B play an important role in tumor progression and have been considered promising therapeutic targets in the development of novel anticancer agents.  Using a bioactivity-guided fractionation, a series of triterpenoids was identified as a new class of competitive inhibitors towards cathepsin L with affinity values in micromolar range.  Most of the evaluated triterpenoids do not inhibit cathepsin B. Thus, the evaluated compounds exhibit a great potential to help in the design of new inhibitors with enhanced potency and affinity towards catL. 
Triterpenoids
Triterpenoids as novel natural inhibitors of human cathepsin L.Cathepsins L (catL) and B play an important role in tumor progression and have been considered promising therapeutic targets in the development of novel anticancer agents.  Using a bioactivity-guided fractionation, a series of triterpenoids was identified as a new class of competitive inhibitors towards cathepsin L with affinity values in micromolar range. 
cathepsin L
Most of the evaluated triterpenoids do not inhibit cathepsin B. Thus, the evaluated compounds exhibit a great potential to help in the design of new inhibitors with enhanced potency and affinity towards catL. 
cathepsin B