Leishmanicidal and reversal multidrug resistance constituents from Aeonium lindleyi.

A new bicyclic diterpene with a labdane skeleton, 7-oxo-labd-8-en-15-ol ( 1), along with two known diterpenes and ten flavonoids were isolated from the leaves of Aeonium lindleyi (Crassulaceae). Their structures were elucidated on the basis of spectroscopic data, including 1D and 2D NMR experiments, and comparison with spectroscopic data reported in the literature. Labdan-8 α,15-diol (2) and labd-8(17)-en-3 β,15-diol (3) showed leishmanicidal activity against Leishmania tropica (IC (50) = 77.0 µM) and Leishmania braziliensis (IC (50) = 68.0 µM) similar to ketoconazole used as positive control. 5,3'-Dihydroxy-3,7,4',5'-tetramethoxyflavone (8) and combretol (9) showed moderate activity (growth inhibition 87.3 and 73.0 %, respectively, at 50 µM) against a multidrug-resistant L. tropica line.