Daphnepedunins G and H, anti-HIV macrocyclic 3,4-seco-daphnane orthoesters from Daphne pedunculata.

Daphnepedunins G (1) and H (2) with unusual macrocyclic 3,4-seco-daphnane orthoester structure were isolated from Daphne pedunculata. Their structures were determined by physicochemical and spectroscopic analyses combined with synthetic methods, including methyl esterification, derivatization reaction using a chiral anisotropic agent, and biomimetic conversion. Compounds 1 and 2 along with their methyl esters 1a and 2a were evaluated for anti-HIV activity, among which 1a and 2a exhibited potent activity with IC50 values of 1.08 and 1.17 µM, respectively.