Elaeocarpionoside, a megastigmane glucoside from the leaves of Elaeocarpus japonicus Sieb. et Zucc.

From a 1-BuOH-soluble fraction of an extract of the leaves of Elaeocarpus japonicus, six megastigmane glucosides (1-6) were isolated. Five were known compounds (2-6), i.e. amelopsisionoside, citroside A, roseoside, alangionoside A and turpinionoside A, respectively. The structure of the new compound, named elaeocarpionoside, was elucidated to be (3R,4R,5S,6S,7E,9R)-megastigman-7-ene-3,4,9-triol 9-O-beta-D: -glucopyranoside by spectroscopic analyses and the modified Mosher's method.