Atramacrolodes A-D (1-4), Four Undescribed Eudesmane-Type Sesquiterpenes from the Rhizome of Atractylodes macrocephala.

Four undescribed sesquiterpenes, atramacrolodes A-D (1-4), along with six known compounds 5-10 were isolated from the rhizome of Atractylodes macrocephala. Compound 3 possessed a new skeleton based on an unprecedented carton-carton connection. Their structures were determined by UV, IR, HRESIMS, NMR spectra, 13 C NMR calculation with DP4 + analysis, and the comparison of experimental and calculated ECD spectra. Compounds 5 and 8 showed protective effects against paracetamol-induced liver cell injury.