Chemical constituents of <i>Crepis napifera</i> (Franch.) Babc. and their anti-inflammatory activities

A chemical study of <i>Crepis napifera</i> led to the isolation and identification of four compounds. Spectroscopic analysis revealed that these compounds belong to the class of eudesmane sesquiterpenes;guaiacane sesquiterpenes and their derivatives, including two novel compounds named Huanyangshen A (<b>1</b>) and Huanyangshen B (<b>2</b>). The absolute configurations of these new compounds were established through the comparison of experimental and calculated ECD spectra. Additionally, the anti-inflammatory properties of these compounds were assessed by evaluating their ability to inhibit LPS-induced NO production in RAW264.7 cells. The results indicated that the compound had potential inhibitory activity. Among them, the IC₅₀ value of compound 1 was 24.97 <i>μ</i>M, which was comparable to the IC₅₀ value of the positive control minocycline (31.54 <i>μ</i>M).