Cynaratriol, ein neues Guajanolid aus der Kardone Cynara cardunculus L. und der Artischocke C. scolymus L. (Compositate)

Cynaratriol, a new guajanolide from Cynara cardunculus L. and C. scolymus L. ( Compositae ) A new guajanolide given the name cynaratriol ( 4 ) was isolated from the leaves of Cynara cardunculus L The structure of 4 and its derivatives 3, 11, 13‐triacetylcynaratriol ( 5 ) and 3, 13‐dibenzoyl‐cynaratriol ( 6 ) was deduced on the basis of IR.‐, 1 H‐NMR.‐, 13 C‐NMR.‐ and mass spectroscopic data. 4 is also present in C. Scolymus L. as shown by GC./MS. analysis. The same absolute configuration is suggested for 4 as found for all other Cynara sesquiterpenes.