Structure of Aloenin, a New Biologically-active Bitter Glucoside from <i>Aloe arborescens</i> var. <i>natalensis</i>

Abstract

Abstract Aloenin, a new bitter glucoside with an inhibitory activity for the gastric juice secretion of rats, was isolated from the leaves of Aloe arborescens Mill. var. natalensis Berger, and the structure was confirmed to be 4-methoxy-6-(2-β-d-glucopyranosyloxy-4-hydroxy-6-methylphenyl)-2-pyrone by means of chemical, spectroscopic, and X-ray crystallographic methods. Ambiguity in the assignment of 2-pyrone-ring carbon signals was clarified by examination of the 13C-NMR spectra of aloenin and the related compounds.