Two new taxoids, taxumairol Q (1) and 13-O-acetyl wallifoliol (2), have been isolated from the leaves and twigs of Taxus sumatrana. Taxuspine F and wallifoliol (10) have been isolated for the first time from the yew T. sumatrana. Seventeen known taxoid diterpenoids have also been isolated. The new derivatives, 9,13-diacetyltaxumairol W (3), 10,13-dibenzoyltaxacustin (4), 7,13-diacetylwallifoliol (5), 7,13-dibenzoylwallifoliol (6), and 7,9-dibenzoyltaxumairol P (7), have been prepared by acylation of a crude mixture of taxoids. All structures were established primarily on the basis of 1D and 2D NMR techniques, including DEPT, COSY, and HMBC experiments, as well as chemical correlation with known compounds. Wallifoliol (10) exhibited significant cytotoxicities against both Hepa 59 T/VGH (human liver carcinoma) and KB (human oral epidermoid carcinoma) tumor cells. Taxuspine F and compound 5 possessed moderate activity against Hepa cells only, while 3, 6, 7, and 10-deacetylbaccatin III showed only marginal activity against Hepa cells.

Chemical investigation of the Taiwanese gorgonian coral Junceella juncea resulted in the isolation of four new briarane‐type diterpenoids, juncenolides H, I, J, and K (1–4). Their structures were determined on the basis of spectroscopic analysis, especially 1‐ and 2D‐NMR. The inhibitory effects of compounds 1–4 on superoxide‐anion generation and elastase release by human neutrophils were evaluated.

Phytochemical investigation of the leaves and twigs of Taxus sumatrana afforded six new taxane diterpene esters, tasumatrols U-Z ( 1- 6). Compounds 2 and 5 contained a rare five-membered lactone ring at C-8, C-9, C-10, and C-19. The structures were established on the basis of detailed spectroscopic analyses, particularly HRESIMS and 2D NMR techniques. Compound 5 showed cytotoxicity against a human hepatoma (Hep2) cell line.