When comparing the IC50 values and the corresponding average
degrees of polymerization (DPn), the results evidence a possible
relationship, as the IC50 values increase with decreasing DPn. For
WM-F2.6, DPn ¼ 5 and IC50 ¼ 2.65 mg/L; for both WM-F2.4 and
WA-F2.2, DPn ¼ 7 while IC50 ¼ 0.39 and 2.26 mg/L, respectively;
and for WM-F2.2, DPn ¼ 8 and IC50 ¼ 0.12 mg/L. These results point
out that flavanols with higher average degrees of polymerization may be associated to greater inhibitory effect. The influence of the
number of monomeric units in the extension and specificity of ACE
inhibition has been already suggested by Actis-Goretta et al. (2003).
Larger procyanidins seem to exert broader interactions on protein
surfaces. A larger procyanidin may reach certain areas of the
enzyme at the same time that cannot be accessed by individual
monomers. In that study, authors suggested that when more
()-epicatechin units the procyanidin structure provides, additional
active groups interact with the enzyme, increasing both the
affinity for the enzyme and the number of binding sites that can be
recognized on ACE surface