A propiophenone derivative of the formula I!: ##STR18## 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 dotted line means the presence or absence of a double bo