The Thymelaeaceae family consists of 53 genera and more than 800 species widely distributed throughout the world except in the arctic zone. Plants of this family characteristically contain daphnane and tigliane diterpenoids (Note 1), which have excellent biological activities, such as anti-cancer and anti-HIV activity. Macrocyclic daphnane orthoesters have excellent anti-HIV activity by eliminating latent HIV-infected cells and are attracting attention as potential novel treatment candidates for against HIV infection, which are different from existing anti-HIV drugs. Daphne pedunculata belongs to the family Thymelaeaceae that is distributed exclusively in Yunnan Province, China. This plant is an evergreen shrub and the yellow flowers bloom between November and December. In this study, a research group isolated 12 macrocyclic daphnane-type diterpenoids, including six new compounds, from D. pedunculata and elucidated their anti-HIV activity. The results of this study have deepened our knowledge of the structure–activity relationship of macrocyclic daphnane orthoesters. These findings are expected to lead to the discovery of new drugs for the treatment of HIV infection.
(Note 1) Diterpenoids
A class of terpene composed of four isoprene units and biosynthesized using geranylgeranyl diphosphate (GGPP) as a precursor. Diterpenes are officially defined as hydrocarbons; therefore, diterpenes with heteroatom-containing functional groups are called diterpenoids.
(Note2) Macrocyclic daphnane orthoester
Among diterpenoids, daphnane-type diterpenoids are compounds characterized by a 5/7/6-membered ring backbone with isopropenyl group. Macrocyclic daphnane orthoesters are compounds with a macrocyclic structure in which the aliphatic chain is linked to the five-membered ring part of the daphnane skeleton via orthoester moiety.
Journal of Natural Products, December 14, 2022.
Daphnepedunins A–F: Anti-HIV Macrocyclic Daphnane Orthoester Diterpenoids from Daphne pedunculata
Lingjian Tan, Kouharu Otsuki, Mi Zhang, Takashi Kikuchi, Misaki Okayasu, Isao Azumaya, Di Zhou, Ning Li, Li Huang, Chin-Ho Chen, Wei Li*