A peroxisome proliferator-activated receptor-gamma agonist and other constituents from Chromolaena odorata.

Peroxisome proliferator-activated receptors (PPARs) are key regulators of lipid and glucose metabolism and have become important therapeutic targets for various diseases. The phytochemical investigation of the chloroform-soluble extract of Chromolaena odorata led to the isolation of a PPAR-gamma agonist, (9 S,13 R)-12-oxo-phytodienoic acid (1), together with 12 other compounds. The structures of chromomoric acid G (2), a new dehydrogenated derivative of 1, and chromolanone (3) were elucidated based on spectroscopic methods. Compound 1 showed a significant effect on PPAR-gamma activation in comparison with rosiglitazone. However, compound 2 was inactive, suggesting that the dehydrogenation of the prostaglandin-like structure in 1 abrogates its PPAR-gamma agonistic activity.