Structurally diverse terpenoids from the rhizomes of Cyperus rotundus L

An extract of the rhizomes of Cyperus rotundus L. afforded two new sesquiterpenoids (2 and 3) with rearranged secoeudesmane and germacrane skeletons, and a new 9,10-seco-cycloartane triterpenoid (9), as well as seven previously reported terpenoids, including a monoterpenoid (1), five sesquiterpenoids (4-8) with guaiane, patchoulane, and eudesmane skeletons, and a 3,4- seco-dammarane nortriterpenoid (10). The structures of 1-10 were elucidated by extensive spectroscopic methods and comparison with the literature data. The structures of 2 and 6 were confirmed by single-crystal X-ray diffraction analysis. The carbon skeleton of 2 is the third example reported thus far of such a skeleton and the 9,10-seco-cycloartane framework of 9 has rarely been found from a natural source. Compound 7 was a new natural product and compounds 1-5 and 7-10 were discovered from the genus Cyperus for the first time. This study may provide some useful information for the chemotaxonomy for the plant Cyperus rotundus.