Fig. 2. Assessment of inhibition of UDP-glucose dehydrogenase by 6TP and 6TU via direct quantification of UDP-glucuronic acid by HPLC separation and quantification. A) Concentration of 6TP, varying UDPG, screened were 0, 50, 75, 100 μM with the calculated slopes of each line equaling 0.0353, 0.0549, 0.0612, 0.0680, respectively. Plotting slopes versus concentration gave a regression line of y = 0.000328x + 0.0364 with a 0.9881 R-square. B) Concentration of 6TU, varying UDPG, screened were 0, 5, 7.5, 10 μM with the calculated slopes of each line equaling 0.0147, 0.0254, 0.0328, 0.0394, respectively. Plotting slopes versus concentration gave a regression line of y = 0.002474x + 0.01416 with a 0.9946 R-square. Each data point for Lineweaver Burk plots are an average of three independent runs with standard error bars shown.