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.