obsolete delphinidin 3-O-glucoside 7-O-glucosyltransferase (feruloyl-glucose dependent) activity (obsolete GO:0102516)
OBSOLETE. Catalysis of the reaction: delphinidin 3-O-beta-D-glucoside + 1-O-feruloyl-beta-D-glucose = delphinidin 3,7-di O-beta-D-glucoside + ferulate + H+.