Supplementary Fig. 1.

Linearity of the reaction as a function of ACE concentrations (A) and reaction time (B). The color development of TNP-HL was monitored for 60 min under ACE concentrations ranging from 2.5 to 20 mU/mL (A) or with 20 mU ACE/mL for various lengths of time (B). ACE inhibitory activity of captopril obtained with ACE concentration of 20 mU/mL and an incubation time of 60 min (C). Upper panel shows the yellow color development of control (C), Blanks (Bs and Bi) and three dilutions of captopril (2, 4 and 6 μg/mL).