Alkamides and a neolignan from Echinacea purpurea roots and the interaction of alkamides with G-protein-coupled cannabinoid receptors

作者：Hohmann Judit^*; Redei Dora; Forgo Peter; Szabo Pal; Freund Tamas F; Haller Jozsef; Bojnik Engin; Benyhe Sandor

来源：Phytochemistry, 2011, 72(14-15): 1848-1853.

DOI：10.1016/j.phytochem.2011.06.008

• Echinacea purpurea
• Asteraceae
• Alkamide
• Neolignan
• Sesquiterpene
• G-protein modulation
• Cannabinoid receptor
• GTP gamma S-binding assay

Multiple chromatographic separations of the CHCl(3)-soluble extract of the roots of Echinacea purpurea led to the isolation of 19 compounds. Four natural products, three alkamides and nitidanin diisovalerianate, were identified, and five further compounds were detected for the first time in this species. Additionally, 10 known E. purpurea metabolites were isolated. The structures were determined by mass spectrometry and advanced 10 and 20 NMR techniques. The bioactivity of the isolated compounds was studied in [(35)S]GTP gamma S-binding experiments performed on rat brain membrane preparations. Both partial and inverse agonist compounds for cannabinoid (CB1) receptors were identified among the metabolites, characterized by weak to moderate interactions with the G-protein signaling mechanisms. The G-protein-modulating activities of the Echinacea compounds are rather far from the full agonist effects seen with the CB1 receptor agonist reference compound arachidonyl-2'-chloroethylamide (ACEA). However, upon coadministration with ACEA, a number of them proved capable of inhibiting the stimulation of the pure agonist, thereby demonstrating cannabinoid receptor antagonist properties.

• 出版日期2011-10