Phytochemical investigation of Crepis incana Sm. (Asteraceae) endemic to southern Greece

Abstract

The genus Crepis L. belongs to the Cichorieae tribe of the Asteraceae family. C. incana Sm. is a narrow endemic species of southern Greece. Crepis L. is well known for its abundance in sesquiterpene lactones. In total, from its aerial parts nine compounds were isolated for the first time, i.e. three guaianolides, grosheimin, crepiside E, crepiside D; two germacranolides, taraxinic acid and its 1′-O-β-d-glucopyranosyl ester, the nor-isoprenoid (3S, 5R)-loliolide and three flavonoids, luteolin, luteolin 7-O-β-d-glucopyranoside and quercetin 3-O-β-d-glucopyranoside. Furthermore, the root extract afforded two triterpenes, oleanolic acid and lupeol. The structures of the isolated compounds were elucidated by high-field NMR spectroscopy.