A lactosyl glycoside or an N-acetyllactosaminyl glycoside useful as foods,
functional food materials, medicines, and reagents is provided with high
yield and inexpensively by using a transfer reaction represented by the
following formula in the presence of an enzyme having an activity of
cleaving a .beta.1,4 glucosyl bond:
LacA-X+Y.fwdarw.LacA-Y+X,
wherein LacA represents lactose or N-acetyllactosaminide; X represents
hydrogen (H), a saccharide, a glycoconjugate, or a phenolic compound; and
Y represents a compound having an alcoholic hydroxyl group or a phenolic
hydroxyl group.
