Alashanoids K-M, bioactive eremophilane sesquiterpenoids from Syringa pinnatifolia

Abstract

Three new eremophilane-type sesquiterpenoids, alashanoids K–M (1–3), and one known analogue (4) were isolated from the peeled stems of Syringa pinnatifolia. All the compounds were isolated from the genus Syringa for the first time. Structures of these compounds were established using 1D and 2D NMR and MS data. The absolute configurations were determined by experimental and calculated electronic circular dichroism analysis, a modification of Mosher’s method, and X-ray diffraction. Compounds 2 and 3 inhibited NO production in LPS-induced RAW264.7 macrophage cells with IC₅₀ values of 14.23 and 12.20 μM, respectively, and showed cytotoxic activities against HepG2 cells with the IC₅₀ values of 34.41 and 40.86 μM, respectively.

Graphical Abstract

Keywords:

• Syringa pinnatifolia
• sesquiterpenoids
• eremophilane
• anti-inflammatory activity
• cytotoxicity

Disclosure statement

No potential confliction of interest was claimed.

Additional information

Funding

This research was funded by the National Natural Science Foundation of China, grant numbers 81473426 and 81774001, and China Key Project at Central Government Level: the ability establishment of sustainable use for valuable Chinese medicine resources (2060302).