Labdane Diterpenoids from Leonotis leonurus

► Eleven labdane diterpenoids were isolated from the leaves of Leonotis leonurus. ► Eight compounds were hitherto unknown. ► All compounds were evaluated for their binding affinities to various CNS receptors. ► Leoleorin C (11) showed weak binding affinity (Ki = 2.9 μM) to the Sigma 1 receptor.