Hydroxyalkenylresorcinols from Stylogyne turbacensis.

Two new compounds, 5-(11'(S)-hydroxy-8'-heptadecenyl)resorcinol (3) and 5-(12'(S)-hydroxy-8',14'-heptadecadienyl)resorcinol (4), were isolated from the leaves of Stylogyne turbacensis together with the known analogue metabolites 1 and 2. Compounds 3 and 4 showed the strongest activity in the leishmania assay, 7 and 3 microM, respectively, while compounds 1, 2, and 4 showed moderate activity against a drug-resistant strain of Trypanosoma cruzi with IC(50) values of 30, 25, and 22 microM, respectively. Additional testing in MCF-7 and NCI-H460 was performed for compounds 3 and 4. The structures of compounds 1-4 were elucidated using NMR, MS, and other spectroscopic data. The absolute stereochemistry of compounds 3 and 4 was also investigated using the Mosher ester approach. Peracetylated derivatives of these four metabolites were produced and their activities determined in the Trypanosoma cruzi assay.