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Five tigliane (1−5) and one ingenane (6) diterpenoids were isolated from the ethanol extract of Euphorbia tirucalli. The structures of these compounds were identified based on analysis of their spectroscopic data. Among them, compound 12-O-(2E,4E,6E,8E-tetradecatetraenoyl)-13-O-isobutyroyl-4β-deoxyphorbol (1) was a new tigliane. The Rho123 effluxion assay showed that tiglianes with a trans-fused 5/7 ring system such as compounds 1, 2, and 4 had potent inhibitory activity against P-glycoprotein in HepG2/ADR cells. [ABSTRACT FROM AUTHOR]

Three new diterpenoids, euphopanes A–C (1–3), including one ent-isopimarane (1), one ent-abietane (2) and one cembrane (3), along with five known compounds (4–8) were isolated from the roots of Euphorbia pekinensis. Their structures were elucidated by extensive spectroscopic analysis, and the absolute configurations of compounds 1–3 were determined by ECD calculations. All the isolates were screened for the cytotoxicity against three cancer cell lines (C4-2B, C42B/ENZR, and MDA-MB-231), and compounds 1, 2, and 4 showed significant cytotoxicity against human prostate cancer cells C4-2B with IC50 values of 14.3, 16.9, and 15.3 μM, respectively. [ABSTRACT FROM AUTHOR]

Phytochemical investigation on the leaves and twigs of Toona ciliata has led to the isolation of four new polyynes (1–4) and two knowns (5 and 6). Their structures were determined by extensive spectroscopic analysis (MS, UV, IR, and NMR) and Mosher's method. All compounds were evaluated for their inhibitory activities against HepG2 human tumor cell line but were inactive. [ABSTRACT FROM AUTHOR]