Revised NMR Data for 9-O-Demethylgalanthine: an Alkaloid from Zephyranthes robusta (Amaryllidaceae) and its Biological Activity
2014
Abstract
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 H-1-H-1 and H-1-C-13 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 mu M), but showed important prolyl oligopeptidase inhibition activity.