Nitric Oxide Inhibitory Dimeric Sesquiterpenoids from Artemisia rupestris
Chen Zhang, Shu Wang, Ke-Wu Zeng, Jun Li, Daneel Ferreira, Jordan K. Zjawiony, Bing-Yu Liu, Xiao-Yu Guo, Hong-Wei Jin, Yong Jiang, Peng-Fei Tu
Journal of Natural Products
Twelve new dimeric sesquiterpenoids (1–12) were isolated from the dried whole plants ofArtemisia rupestris. Their structures were determined using MS and NMR data, and the absolute configurations were elucidated on the basis of experimental and calculated ECD spectra. Compounds 1–9 are presumably formed via biocatalyzed [2+2] or [4+2] cycloaddition reactions. Stereoselectivity of the [4+2] Diels–Alder reaction dictated the formation of endo-products. The dimeric sesquiterpenoids exhibited moderate inhibition on NO production stimulated by lipopolysaccharide in BV-2 microglial cells, with IC50 values in the range 17.0–71.8 μM.
Circular dichroism, Absolute configuration, Natural products