摘要Atractylodimers A-D(1-4),sesquiterpenoid dimers(SDs)featuring a unique cage-like struc-ture,were isolated from the rhizomes of Atractylodes macrocephala.The most distinctive characteristic of these isolates was the highly twisted"cap"structure based on highly twisted five-membered oxygen heterocyclic rings.Notably,compound 1 contained a furo[2,3b]furan ring,a caged 3,10-oxa-tricyclo[5.2.1.04,9]decane moiety,and 6/6/5/5/5/5/6/6 octocyclic skeleton.Compounds 2-3 exhibited a spiro-tetrahydrofuran ring,while compound 4 incor-porated a caged spiro-2,5,9-oxa-tricyclo[5.2.1.04,10]decane scaffold for unit linkage.Their structures were definitively established through spectroscopic methods and X-ray diffraction experiments.Plausible biosynthetic pathways of compounds 1-4 were proposed.Com-pounds 1 and 2 demonstrated significant neuroprotective effects against serum deprivation-induced PC12 cell damage.