Figure 3

Analysis of specificity of recombinant UGT. a) Analysis of specificity of recombinant UGT by UPLC, 1.: Standards of kaempferol glucosides and kampferol. 2.:Standard of kaempferol 3.: Chromatogram of standard kaempferol incubated with recombinant glycosyltransferase. Incubation with recombinant UGT, UDP-glucose, and keampferol produced a major product with the expected retention time and UV spectrum of keampferol-7-O-glucoside. The enzyme assay and product analysis is described in the Methods section. b) Analysis of specificity of recombinant UGT by HPLC. 1.: Standard of peonidin-3-O-glucoside, 2.: Standard of peonidin chloride., 3.: Chromatogram of standard peonidin chloride incubated with recombinant glycosyltransferase. Incubation with recombinant UGT, UDP-glucose, and peonidin chloride produced a major product with the expected retention time and UV spectrum of peonidin-3-O-glucoside. The enzyme assay and product analysis is described in the Methods section. c). Substrate specificity of recombinant UGT. The substrate specificity was measured as described in the Methods section with the use of UDP-Glu as a glucose donor. The mean value (n = 4) ± SE is presented.