title: New eremophilane-type sesquiterpenes from Ligularia lapathifolia.
abstract: Seven new eremophilanolides were isolated from the roots and rhizomes of Ligularia lapathifolia. Their structures were established as 3beta-angeloyloxy-8beta H-eremophil-7(11)-ene-12,8alpha (14beta, 6alpha)-diolide, 3beta-angeloyloxy-8beta-hydroxyeremophil-7(11)-ene-12,8alpha(14beta,6alpha)-diolide,3beta-angeloyloxy-8beta-methoxyeremophil- 7(11)-ene-12,8alpha(14beta,6alpha)-diolide,3beta-angeloyloxy-8beta-ethoxyeremophil-7(11)-ene-12, 8alpha (14beta,6alpha)-diolide, 3beta-angeloyloxy-10beta- hydroxyeremophil-8(9),7(11)-diene-12,8(14beta,6alpha)-diolide, 3beta-angeloyloxy-8,12-expoy-12alpha-hydroxy-8beta-methoxyeremophil-7(11)-en-14beta,6alpha-olide and 3beta-angeloyloxyeremophilan-7,11-dien-14beta,6alpha-olide, by means of spectroscopic analyses. Moreover, application of a photooxygenation reaction on 7 resulted in the generation of 2 with an alpha,beta-unsaturated gamma-lactone moiety. This biomimetic transformation supports a biogenetic pathway proposed for 2.
authors.affiliation: Shanghai Institute of Materia Medica, Chinese Academy of Sciences, P. R. China. sinodlsia@yahoo.com
authors.forename: Yun-Sen
authors.initials: YS
authors.lastname: Li
authors.forename: Zheng-Tao
authors.initials: ZT
authors.lastname: Wang
authors.forename: Mian
authors.initials: M
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Zhou
authors.forename: Ji-Jun
authors.initials: JJ
authors.lastname: Chen
authors.forename: Shi-De
authors.initials: SD
authors.lastname: Luo
mesh_terms: D019659:Asteraceae; D006801:Humans; D010084:Oxidation-Reduction; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry*; D018517:Plant Roots; D027343:Rhizome; D012717:Sesquiterpenes / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D012717:Sesquiterpenes