Preparative-Scale Isolation of Four Anthocyanin Components of Black Currant (Ribes nigrum L.) Fruits

Four anthocyanin components of black currant, delphinidin 3-O-β-rutinoside (D3R), cyanidin 3-O-β-rutinoside (C3R), delphinidin 3-O-β-glucoside (D3G), and cyanidin 3-O-β-glucoside (C3G), were successfully isolated as crystalline forms on a preparative scale. In this process, selective hydrolysis of the glucosides (D3G and C3G) and rhamnosides (D3R and C3R) was achieved by treatment with β-glucosidase and hesperidinase (α-rhamnosidase), respectively, to improve resolution of anthocyanin components. Especially, selective conversion of the rutinosides into glucosides made the amounts of D3G and C3G increase about 4- and 7-fold, respectively. D3R, C3R, D3G, and C3G were isolated from enzymatic hydrolysates of black currant anthocyanins through Amberlite XAD-7HP absorption followed by preparative HPLC separation, and their crystals were obtained as the flavylium chloride. Keywords: Anthocyanin; blackcurrant; delphinidin 3-O-β-rutinoside; cyanidin 3-O-β-rutinoside; hesperidinase