Sesquiterpenoids and Phenolics from Crepis conyzifolia Wanda Kisiel* and Klaudia Michalska Department of Phytochemistry, Institute of Pharmacology, Polish Academy of Sciences, Pl-31-343 Krakow, Poland. Fax: +48 126374500. E-mail:
[email protected] * Author for correspondence and reprint requests Z. Naturforsch. 56c, 961-964 (2001); received July 30/August 28, 2001 Crepis conyzifolia, Sesquiterpenoids, Phenolics From the roots of Crepis conyzifolia, two new and two known guaianolides were isolated together with three known phenylpropanoids. Structures of the new compounds were estab lished as 8ß-hydroxy-4ß, 15-dihydrozaluzanin C and 4ß, 15, llß, 13-tetrahydrozaluzanin C-3- O-ß-glucopyranoside by spectral methods. The identity of 8 -epiisolippidiol and dentalactone was also discussed. Introduction previously isolated from Crepis and Lactuca spe cies in our laboratory (Kisiel, 1983; Kisiel and Screening tests for potential anticancer agents Barszcz, 1995; Kisiel and Barszcz, 1997; Kisiel et from natural sources showed that crude alcoholic al., 2000). The identity of cichoriin (7) was estab extracts from plants belonging to the tribe Lactu- lished by comparison of its spectral data with those ceae of the Asteraceae exhibited chemoprotective in the literature (Kuwajima et al., 1992). The com effects on chemical carcinogenesis and differentia pound is reported for the first time from Crepis tion-inducing activities on human leukemia and species. Since no complete XH NMR data are mause melanoma cell lines. Some bioactive triter- available for 4 (Kisiel, 1983), we have included all pene and sesquiterpene lactone constituents of the our assignments in Table I, along with unreported plant extracts were isolated and identified (Taka- 13C NMR data in CDC13 and pyridine-d5.