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Two new lathyrane diterpenoids, euphanoids A and B (1 and 2), along with five known compounds (37) were isolated from the roots of Euphorbia kansuensis. Their structures were elucidated by spectroscopic analysis, and the absolute configuration of 1 was determined by single crystal X-ray diffraction. All of the isolates were screened for the inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 cells, and compounds 1 and 2 showed pronounced inhibition on NO production with IC 50 values of 4.7 and 9.5 M, respectively, being more active than the positive control, quercetin (IC 50  10.8 M).

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Euphorkanlide A (1), a highly modified ingenane diterpenoid with a C 24 appendage forming an additional hexahydroisobenzofuran-fused 19-membered macrocyclic bis-lactone ring system was isolated from the roots of Euphorbia kansuensis. Its structure was determined by extensive spectroscopic analysis and quantum-chemical calculations. Compound 1 showed significant cytotoxicities against a panel of cancer cell lines (IC 50s < 5 μM). Mechanistic study revealed that 1 could induce the generation of ROS, leading to cell cycle arrest and cell apoptosis in drug-resistant cancer cell line HCT-15/5-FU.

cetane and tricyclo[8.4.1.0 3,7 ]pentadecane skeleton, respectively, were isolated from the seeds of Euphorbia lathyris. Their structures were determined by detailed spectroscopic analysis and were further confirmed by single-crystal X-ray diffraction. 1 significantly inhibited adipogenesis in 3T3-L1 adipocytes by retarding cell differentiation at the early stage.

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Importins are overexpressed in many cancers and mediate the abnormal nuclear transport of oncogenic factors. The druggable potential of importins still remains unclear, largely because of the lack of potent inhibitors. Herein, the anti-castration-resistant prostate cancer (CRPC) screening of a Euphorbiaceae diterpenoid library followed by target fishing led to the identification of a highly potent importin-β1 inhibitor, daphnane diterpenoid DD1. DD1 selectively inhibited the growth and survival of CRPC cells at subnanomolar concentrations and completely blocked tumor growth in preclinical models at an extremely low dosage. Mechanistic studies revealed that targeting of importin-β1 by DD1 significantly reduced the nuclear accumulation of key CRPC drivers, shutting down their downstream oncogenic signaling. Disruption of the predicted binding sites of DD1 on importin-β1 abolished this anti-CRPC effect. These findings suggest that importin-β1 is an effective therapeutic target in CRPC and that DD1 as the most potent importin-β1 inhibitor to date can be developed as therapeutics for treatment of this disease.