FIGURE 3.

HPLC analysis of UGGT/ECGT enzyme assay extracts. A and C, the UGGT/ECGT assay solution was incubated at 30 °C for 1.5 h in a total volume of 1.5 ml containing 50 mm phosphate buffer (pH 6.0), 0.4 mm nongalloylated catechins (EGC or EC), 1.4 mm GA, 2.3 mm UDPG, 4 mm ascorbic acid, 1.5 mm salicylic acid, and crude enzyme extract (0.55 mg total of protein). The products βG and galloylated catechins EGCG or ECG were detected clearly in this two-step reaction enzyme assay. Peaks were identified by comparing the retention times with standards. B and D, control treatments of the UGGT/ECGT assay extracts with the crude enzyme extract were heated to 100 °C to inactivate enzyme activities. There were no enzymatic products in control treatments. AU, absorbance units.