A novel norsesquiterpene, named norcyperone (1), and three known compounds: (-)-clovane-2,9-diol (2), rosenonolactone (3), and 5 alpha,8 alpha-epidioxy-(20S,22E,24R)-ergosta-6,22-dien-3beta-ol (4) were isolated from the rhizomes of Cyperus rotundus L. The structure of 1 was elucidated as 8,11,11-trimethylbicyclo[5.3.1]undecane-5 alpha, 8 alpha-epoxy-3-one on the basis of extensive spectroscopic...
