Sesquiterpenoids and phenolics from roots of Cichorium endivia var. crispum

Endive (Cichorium endivia L.) and chicory (C.intybus L.) are the most popular species of the genus Cichorium

(Asteraceae, Lactuceae). Leaves of commercial varieties are used as a salad additive or a vegetable and roots are considered wastes. Chicory is also known as a traditional herbal remedy which improve digestive and metabolic functions. A single report [1] on sesquiterpene lactones of C. endivia roots revealed the presence of germacranolides, eudesmanolides and lactucin-like guaianolides.

We have undertaken an investigation of roots of C. endivia L. var. crispum Lam. The dried roots were extracted with ethanol and the extract, after sequential fractionation on silica gel followed by semipreparative RP HPLC, gave 13 sesquiterpene lactones, including 11 guaianolides, and three phenolics. The guaianolides 8-deoxylactucin and lactucopicrin appeared to be major sesquiterpene lactone constituents, and the guaianolides hieracin II and macrocliniside G were found in Cichorium species for the first time. Moreover, a new natural product was isolated and characterized as 10β-methoxy-1α (10), 11β(13)-tetrahydrolactucin. In addition, the roots yielded methyl- and ethyl p-hydroxyphenylacetates, and ethyl trans-caffeate, the latter in a relatively high amount. The formation of the ethyl esters is likely to occur during the extraction procedure. All the compounds were characterized by spectral methods. 8-Deoxylactucin, also known as the major sesquiterpenoid of chicory roots [2], was reported to inhibit DNA binding of the transcription factor NFκB [3] and cyclooxygenase-2 protein expression [4].

References: 1. Seto, M. et al. (1988), Chem. Pharm. Bull. 36: 2423. 2. Kisiel, W., Zielinska, K. (2001), Phytochemistry 57: 523. 3. Siedle, B. et al. (2004), J. Med. Chem. 47: 6042. 4. Cavin, C. et al. (2005), Biochem. Biophys. Res. Commun. 327: 742.