New eudesmane and eremophilane derivatives from Laggera alata

From the aerial part of Laggera alata, a novel eremophilanoid (1) as well as two new eudesmanoids (2-3) were isolated. Their structures were elucidated by 2D-NMR technique and X-ray diffraction studies. The cytotoxic activities of these sesquiterpenes were also investigated.