Imperatorin

Imperatorin is a furocoumarin and a phytochemical that has been isolated from Urena lobata L. (Malvaceae), Angelica archangelica, Angelica dahurica, Glehnia littoralis, Saposhnikovia divaricata, Cnidium monnieri, Incarvillea younghusbandii, and Zanthoxylum americanum mill. It is biosynthesized from umbelliferone, a coumarin derivative.

Isolation
The procedure for the isolation of imperatorin from Urena lobata involves exhaustively extracting under reflux with benzene the air-dried and pulverised roots followed by separation by column chromatography.

Biochemical activity
Imperatorin was identified from a Bioactive Molecules library in a high throughput screening experiment for inhibitors of the phosphodiesterase PDE4. It displays a significant preference for PDE4B over PDE4A. Imperatorin has been shown to have anti-inflammatory activity in chondrocytes. Imperatorin treatment inhibits the expression of iNOS and suppresses the production of NO in osteoarthritic chondrocytes.