Quinone methides

Celastrol (tripterine) is a bioactive chemical compound isolated from the roots of Tripterygium wilfordii (Thunder duke vine) and Tripterygium regelii (Regel's threewingnut). Celastrol is a pentacyclic and belongs to the family of quinone methides. It has been used for centuries as a traditional Chinese medicine. In recent years, celastrol has been widely studied for its anti-inflammatory, anticancer, antioxidant, and antibacterial properties.

Taxodone is a naturally occurring diterpenoid found in Taxodium distichum (bald cypress), Rosmarinus officinalis (rosemary), several salvia species and other plants, along with its oxidized rearrangement product, taxodione. Taxodone and taxodione exhibit anticancer, antibacterial, antioxidant, antifungal, insecticide, and antifeedant activities.

Kendomycin is an anticancer macrolide first isolated from Streptomyces violaceoruber. It has potent activity as an endothelin receptor antagonist and anti-osteoporosis agent. It also has strong cytotoxicity against various tumor cell lines.