Lignans from Euphorbia hirta L.

Abstract

Five new lignans, euphorhirtins A–D (1–4), 5-methoxyvirgatusin (5), three artefacts, 7S-ethoxyisolintetralin (6), 7R-ethoxyisolintetralin (7), and 7R-ethoxy-3-methoxyisolintetralin (8), together with 13 known ones (9–21) were isolated from the medicinal plant Euphorbia hirta L. The structures of the compounds were elucidated by means of extensive spectroscopic analysis, including 1D and 2D NMR and HR-ESI-MS experiments. The absolute configurations of compound 1 was determined by ECD calculation. The isolates were evaluated for their inhibitory effects against the proliferation of the cancer cell lines (Hep G2, A549, and DU145) and compounds 14 and 18 showed inhibitory activity against the Hep G2 cells with IC₅₀ values 7.2 ± 0.17 and 8.5 ± 0.36 μM.

Graphical Abstract

Keywords:

• Anti-proliferative activity
• ECD calculation
• Euphorbia hirta L.
• HR-ESI-MS
• Lignans
• NMR

Supplementary material

¹H and ¹³C NMR data, key HMBC (H→C), ¹H-¹H COSY (▬) and NOESY (H↔H) correlations, CD spectra of 1–4 and 6–8, Experimental and calculated ECD spectra of 1, 1D and 2D NMR, HRESIMS, and IR spectra of 1–8.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Financial support from the National Natural Science Foundation of China (No. 21877071), Science & Technology Development Plan Project of Shandong Province (No. 2014GSF118023), and Young Scholars Program of Shandong University (No. YSPSDU2015WLJH50) is gratefully acknowledged.