MEG is a selective iNOS inhibitor and scavenger of peroxynitrite. The EC50 values for inhibition of iNOS (LPS-treated rat lung), eNOS (bovine endothelial), and nNOS (rat brain) are 11.5, 110, and 60 µM, respectively. MEG reacts with peroxynitrite with a second order rate constant of 1,900 M−1s−1 at 37°C. MEG has potent anti-inflammatory activity, which may be due to the combined effect of MEG acting as an inhibitor of iNOS and as a scavenger of peroxynitrite.