Recent progress in the development of natural ent-kaurane diterpenoids with anti-tumor activity

The ent-kaurane diterpenoids are widely distributed in China, some of which have high natural abundance in plants of Isodon, Pteris, Gnaphalium, Diplospora, Croton and some other species. These compounds exhibit significant anti-tumor, antibacterial and anti-inflammatory activities, which have attracted the attention of medicinal chemists. This review focuses on the recent advances in the research of derivatives, anti-tumor activity, mechanism of action, and structure-activity relationships of ent-kaurane diterpenoids. All of these will show the potential in the development of new antitumor agents in natural products.