Taxane Diterpenoids from Taiwanese Yew Taxus sumatrana

Thirty seven taxanes were characterized from the leaves and twigs of Taiwanese yew ( Taxus sumatrana , Taxaceae). Four of these metabolites are new and designated as sumataxins A–D ( 1 – 4 ). Compound 1 possesses an 11(15→1),11(10→9)‐di‐ abeo ‐taxane skeleton with an unusual spiro‐connected 2,2‐dimethyl‐1,3‐dioxolane ring at C(4), whereas compound 2 has a rare β‐ OH orientation at C(13) of taxane diterpene ester. In addition, sumataxin C ( 3 ) is formulated as an 11(15→1)‐ abeo ‐taxane with a 4,5‐acetonide ring skeleton. Compound 4 is the first metabolite with a 4,20‐epoxy‐taxane structure. The structures of all the taxanes were established by spectroscopic methods. All compounds were evaluated for anti‐HSV‐1 and PBMC activities. Compound 9 exhibited significant enhancement of cell proliferation on peripheral blood mononuclear cells.