New eremophilane-type sesquiterpenes from Ligularia lapathifolia.
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.
Li
Yun-Sen
YS
Shanghai Institute of Materia Medica, Chinese Academy of Sciences, P. R. China. sinodlsia@yahoo.com
Wang
Zheng-Tao
ZT
Zhang
Mian
M
Zhou
Hui
H
Chen
Ji-Jun
JJ
Luo
Shi-De
SD
D019659:Asteraceae; D006801:Humans; D010084:Oxidation-Reduction; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry*; D018517:Plant Roots; D027343:Rhizome; D012717:Sesquiterpenes / Q000737:chemistry*
D010936:Plant Extracts; D012717:Sesquiterpenes