Daphnepedunins A-F, Anti-HIV Macrocyclic Daphnane Orthoester Diterpenoids from Daphne pedunculata

From the whole plant of Daphne pedunculata, 12 macrocyclic daphnane diterpenoids, including six new compounds, daphnepedunins A-F (1-4, 9, and 10), were isolated. Their structures were elucidated by physiochemical and spectroscopic data analysis, the modified Mosher's method, and X-ray crystallography. The isolated compounds were evaluated for anti-HIV activity against HIV-1 infection in MT4 cells and showed significant anti-HIV activity with IC₅₀ values of 36.3-994 nM. A consideration of the anti-HIV activity of these compounds provided further insight into the structure-activity relationships of macrocyclic daphnane diterpenoids.