Ten guaianolides, including three previously unreported natural products, were isolated from the aerial parts of Cichorium intybus (Asteraceae), more commonly known as chicory. Two of the new compounds ( 8 and 9) were analogues of lactupicrin and 11/β,13-dihydrolactupicrin, respectively, with the C-15 oxidized to the aldehyde state. The third new natural product, which we have called mtybulide A (10), is an isomer of lactucin with the lactone closed to the C-8 oxygen rather than the C-6