New eudesmane-type sesquiterpenoids from the processed rhizomes of Atractylodes macrocephala.

Two new eudesmane-type sesquiterpenoids, eudesma-4(15),7(11)-dien-8α,12-ether (atractylenother, 1) and 8α-hydroxyeudesma-4(15),7(11)-dien-8β,12-olide (8-epiatractylenolide III, 2), and one new natural product named 4(R),15-epoxy-8β-hydroxyatractylenolide II (3), together with four known eudesmane-type sesquiterpenoid lactones, atractylenolides I, II, III, and IV, were isolated from the rhizome of Atractylodes macrocephala Koidz. processed with wheat bran. Their chemical structures were determined by the combination of 1D and 2D NMR analysis as well as mass spectrometry.