The present invention relates to a propiophenone derivative of the formula I!: ##STR2## wherein X is an oxygen atom, a sulfur atom or a methylene group, OY is a protected or unprotected hydroxy group, Z is a ??-D-glucopyranosyl group or 4-O-(??-D-glucopyranosyl)-??-D-glucopyranosyl group wherein one or more hydroxy groups of these groups may optionally be acylated, and the doffed line means the pr