Constituents of leaves and their antimalarial and antifungal activity.

From the leaves of (an aquatic plant), one new compound, 24()-ethylcholest-6-ene-5α-ol-3--β-D-glucopyranoside (), along with 11 known metabolites (-), were isolated and identified by spectroscopic methods including 1D- and 2D NMR. Antifungal activity for ()-roemerine () (IC/MIC = 4.5/10 μg/mL against ) and antimalarial activity for ()-roemerine () and -methylasimilobine () (IC = 0.2 and 4.8 μg/mL for the D6 clone, respectively, and 0.4 and 4.8 μg/mL for the W2 clone, respectively) was observed. None of the compounds were cytotoxic to Vero cells up to a concentration of 23.8 μg/mL. NMR data for 10-eicosanol () and 7,11,15-trimethyl-2-hexadecanone () are presented for the first time. An analysis of the structure-activity relationship shows that the substituents in position C-1 and C-2 of aporphine alkaloids are crucial for the antimalarial activity.