Ongoing studies of Zephyranthes robusta resulted in the isolation of the lycorine-type alkaloid previously called carinatine and 10- O-demethylgalanthine. The NMR data given previously for this compound were revised and completed by two-dimensional ¹H-¹H and ¹H-¹³C chemical shift correlation experiments. The name of the isolated compound was corrected to 9- O-demethylgalanthine in accordance with the currently used system of numbering of lycorine-type alkaloids. 9- O-Demethylgalanthine and galanthine, a previously isolated alkaloid from Z. robusta, were inactive in acetylcholinesterase/butyrylcholinesterase assays (IC₅₀ > 500 μM), but showed important prolyl oligopeptidase inhibition activity.