Two New Sesquiterpenes from Ligularia lankongensis

✍ Scribed by Ai-Min Tan; Hong-Ping He; Mian Zhang; Zheng-Tao Wang; Xiao-Jiang Hao

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: German
• Weight: 58 KB
• Volume: 90
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.200790000

✦ Synopsis

Introduction. -The genus Ligularia has been taxonomically placed in the Compositae (tribe Senecioneae), and comprises ca. 100 species in China [1]. Some 27 species in this genus have long been used as folk remedies for their antibiotic, antiphlogistic, and antitumor activities [2]. Ligularia plants are chemotaxonomically characteristic due to the presence of typical pyrrolizidine alkaloids and sesquiterpenoids. In previous studies [3] [4], we reported on several new pyrrolizidine alkaloids. Ligularia lankongensis (FRANCH.) HAND.-MAZZ. mainly grows in the northern parts of Yunnan and in the southwest of Sichuan, China. Its underground parts have been used as expectorant and antibechic remedy in the local areas. Up to date, the bioactive components of this herb have not been disclosed. In continuation of our phytochemical investigations on Ligularia species, we herein report two new, highly oxygenated bisabolane sesquiterpenes, compounds 1 and 2, from L. lankongensis. Bisabolane sesquiterpenes are most distributed in Compositae, especially in the genera Cremanthodium [5], Ligularia [6], Artemisia [7], and Senecio [8]. Results and Discussion. -Compound 1 was obtained as a colorless gum. The 1 H-and 13 C-NMR (DEPT) spectra indicated 15 skeletal C-atoms: three Me, two CH 2 , and seven