Molecular cloning, substrate specificity of the functionally expressed dihydroflavonol 4-reductases from Malus domestica and Pyrus communis cultivars and the consequences for flavonoid metabolism - Fischer, Thilo C.; Halbwirth, Heidrun; Meisel, Barbara; Stich, Karl; Forkmann, Gert (Archives of Biochemistry & Biophysics, 2003)