title: Liver X receptor and peroxisome proliferator-activated receptor agonist from Cornus alternifolia.
abstract: BACKGROUND
  Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear receptors superfamily and are transcription factors activated by specific ligands. Liver X receptors (LXR) belong to the nuclear hormone receptors and have been shown to play an important role in cholesterol homeostasis. From the previous screening of several medicinal plants for potential partial PPARγ agonists, the extracts of Cornus alternifolia were found to exhibit promising bioactivity. In this paper, we report the isolation and structural elucidation of four new compounds and their potential as ligands for PPAR.
  
  
  METHODS
  The new compounds were extracted from the leaves of C. alternifolia and fractionated by high-performance liquid chromatography. Their structures were elucidated on the basis of spectroscopic evidence and analysis of their hydrolysis products.
  
  
  RESULTS
  Three new iridoid glycosides including an iridolactone, alternosides A-C (1-3), a new megastigmane glycoside, cornalternoside (4) and 10 known compounds, were obtained from the leaves of C. alternifolia. Kaempferol-3-O-β-glucopyranoside (5) exhibited potent agonistic activities for PPARα, PPARγ and LXR with EC50 values of 0.62, 3.0 and 1.8 μM, respectively.
  
  
  CONCLUSIONS
  We isolated four new and ten known compounds from C. alternifolia, and one known compound showed agonistic activities for PPARα, PPARγ and LXR.
  
  
  CONCLUSIONS
  Compound 1 is the first example of a naturally occurring iridoid glycoside containing a β-glucopyranoside moiety at C-6.
authors.affiliation: Department of Applied Chemistry, Xi'an University of Technology, Xi'an 710048, China.
authors.forename: Yang-Qing
authors.initials: YQ
authors.lastname: He
authors.forename: Guo-Yi
authors.initials: GY
authors.lastname: Ma
authors.forename: Jiang-nan
authors.initials: JN
authors.lastname: Peng
authors.forename: Zhan-Ying
authors.initials: ZY
authors.lastname: Ma
authors.forename: Mark T
authors.initials: MT
authors.lastname: Hamann
mesh_terms: D000818:Animals; D016466:CHO Cells; D049109:Cell Proliferation / Q000187:drug effects*; D029768:Cornus / Q000737:chemistry*; D006224:Cricetinae; D056945:Hep G2 Cells; D006801:Humans; D057889:Iridoid Glycosides / Q000737:chemistry / Q000494:pharmacology*; D000071518:Liver X Receptors; D057093:Orphan Nuclear Receptors / Q000819:agonists*; D047492:Peroxisome Proliferator-Activated Receptors / Q000819:agonists*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D057889:Iridoid Glycosides; D000071518:Liver X Receptors; D057093:Orphan Nuclear Receptors; D047492:Peroxisome Proliferator-Activated Receptors; D010936:Plant Extracts