obsolete curcumin-4'-O-beta-D-gentiotrioside 1,6-glucosyltransferase activity (obsolete GO:0102422)
OBSOLETE. Catalysis of the reaction: curcumin 4'-O-beta-D-gentiotrioside + UDP-alpha-D-glucose = curcumin 4'-O-beta-D-gentiotetraside + UDP + H+.