One new 12, 8-guaianolide sesquiterpene lactone with antihyperglycemic activity from the roots of Cichorium intybus

Abstract

Three 12, 8-guaianolide sesquiterpene lactones, including a new compound intybusin F (1), and a new natural product cichoriolide I (2), along with six known 12, 6-guaianolide compounds (4–9) were isolated from the roots of Cichorium intybus L. Their structures were determined by extensive spectroscopic analysis. The absolute configurations of new compounds were elucidated based on analysis of the experimental and calculated electronic circular dichroism spectra. Compounds 1, 2, 4, 7, 8 showed significant effects on facilitating the glucose uptake in oleic acid plus high glucose-stimulated HepG2 cells at 50 μM. In addition, compounds 1, 2, 3, 6, 7 exhibited obvious inhibitory effects against NO production, of them, compounds 1, 2, 7 can significantly decrease the secretion of inflammatory cytokines (TNF-α, IL-6 and COX-2) levels in this hyperglycemic HepG2 cell model.