Subscribe to RSS
DOI: 10.1055/s-0032-1320804
New labdane diterpenes from Leonotis leonurus and their biological activities
Leonotis leonurus (Lamiaceae), is native to South Africa and has been reported to cause mild marijuana-like sedative effects when smoked or consumed as a tea. Three new labdanes, leonurenones A-C (1-3) were isolated and characterized from a commercial source of Leonotis leonurus. Genetic methods allowed for identification of the plant material. The new compounds contain an uncommon α,β-unsaturated enone moiety in ring B. Compounds 1 and 2 were evaluated in a competitive inhibition assay at the GABA A neuroreceptor site. The aqueous extract has GABAA activity. However, compounds 1 and 2 isolated herein did not show any activity at this receptor, indicating that these compounds are not by themselves responsible for the activity.
Keywords : labdane; leonurenone; Leonotis leonurus ; isolation