Daphnane-type diterpene esters with cytotoxic and anti-HIV-1 activities from Daphne acutiloba Rehd.

Seven previously unreported daphnane-type diterpene esters named acutilobins A-G, together with 12 known ones, were isolated from EtOAc extract of Daphne acutiloba Rehd. Their structures were elucidated based on the spectroscopic data. The cytotoxic and anti-HIV-1 activities of these daphnane-type diterpene esters were evaluated through bioassays. Fourteen of these isolates exhibited definite cytotoxic activities against the five human tumor cell lines HL-60, SMMC-7721, A-549, MCF-7, and SW480. Additionally, anti-HIV-1 activities were observed in 13 daphnane-type diterpene esters, among which acutilobins A-G exhibited significant anti-HIV-1 activities with EC₅₀ below 1.5 nM and SI over 10,000. Particularly, genkwanineVIII showed the strongest activity with EC₅₀ 0.17 nM and SI 187,010.