Fimbrialtols K-M, highly functionalized ent-kaurane diterpenoids from traditional Chinese plant Flickingeria fimbriata (B1.) Hawkes

Three new ent-kaurane diterpenoids fimbrialtols K-M (3-5) with highly substituted functionalities were isolated from the extract of Flickingeria fimbriata (B1.) Hawkes. Compounds 3 and 4 contain a cinnamic carboxyl group, whereas compound 5 possesses a benzoic carboxyl group representing the first report in more than known 600 ent-kaurane diterpenoids.