Monoterpenoid indole alkaloids from Gardneria ovata.

Eight new monoterpenoid indole alkaloids, gardfloramine-9-O-β-D-glucopyranoside (1), 19(E)-18-demethoxygardfloramine-N(4)-oxide (2), gardfloramine-N(4)-oxide (3), 18-demethylgardfloramine (4), 19(E)-9,18-didemethoxygardneramine (5), 19(E)-11-methoxy-9,18-didemethoxygardneramine (6), 9-demethoxy-18-demethylgardneramine (7), and minfiensine-N(4)-oxide (8), along with six known alkaloids, were isolated from Gardneria ovata. The structures of the new alkaloids were established by means of spectroscopic methods. None of the compounds were cytotoxic to five human cancer cell lines.