On the occurrence of sonchuside A in Cicerbita alpina and its chemosystematic significance

The subaerial parts of Cicerbita alpina yielded the guaianolide 8-acetyl-15b-D-glucopyranosyllactucin (1) and the germacranolide Sonchuside A (2). The sonchuside A is reported for the first time from the genus Cicerbita. 1H-NMR and 13C NMR data of compounds 1 and 2 measured in deuterodimethyl sulfoxide and deuteromethanol, respectively, are given and the chemosystematic implications of the occurrence of sonchuside A in C. alpina are discussed briefly.