Isolated from the plants Matthiola incana (stock) [1] and Arabidopsis thaliana (mouse-eared cress) [2]. The enzyme has similar activity with the 3-glucosides of pelargonidin, cyanidin, delphinidin, quercetin and kaempferol as well as with cyanidin 3-O-rhamnosyl-(1->6)-glucoside and cyanidin 3-O-(6-acylglucoside). There is no activity with other UDP-sugars or with cyanidin 3,5-diglucoside.