Figure 4: Double-reciprocal plots of the inhibition kinetics of acarbose and norathyriol toward α-glucosidase. In the assay, α-glucosidase (0.48 u/mL) was preincubated with the indicated inhibitors for 10 min at 37°C, and the reactions were initiated by adding substrate (PNP-G) in following dose from 0.33 to 0.020 mM.