Inhibition of α-Amylases by Condensed and Hydrolysable Tannins: Focus on Kinetics and Hypoglycemic Actions

Figure 5

Reaction rates of the porcine pancreatic α-amylase measured by varying simultaneously the substrate (starch) and the hydrolysable tannin (a) or condensed tannin (b) concentrations. Each datum point is the mean of four determinations. The lines running through the experimental points were calculated using optimized parameters obtained by fitting (5) ((a) hydrolysable tannin) or (6) ((b) condensed tannin) to the experimental data by means of a nonlinear least-squares procedure. Values of the optimized parameters and goodness-of-fit indicators for the hydrolysable tannin data (panel (a); equation (5)) are ,  g/100 mL; ,  μmol/min; ,  μM; ,  μM; sum of squared deviations, 0.0101; MSC, 4.545. For the condensed tannin data (panel (b); equation (6)) the optimized parameters are K_M,  g/100 mL; ,  μmol/min; ,  μM; ,  μM; ,  μM; sum of squared deviations, 0.00786; MSC, 4.793.

(a)

(b)