Calcium, magnesium and zinc 2,5-dihydroxybenzenesulfonates (dobesilates) were synthesized by sulfonation of hydroquinone with sulfuric acid under mild conditions. To form the salts, neutralization with calcium carbonate followed by cation exchange by means of magnesium or zinc sulfates was performed. The dobesilates were characterized by standard spectral methods and by AAS for metal content and then tested for inhibitory activity against aminopeptidase N. The calcium and magnesium 2,5-dihydroxybenzenesulfonates exhibited rather weak inhibitory activity to aminopeptidase N, as demonstrated by the IC 50 values of 978.0 and 832.1 μmol L -1 , respectively, while zinc 2,5-dihydroxybenzenesulfonate reached a more significant inhibitory activity characterized by an IC 50 value of 77.4 μmol L -1 . The results of the inhibition activity suggest that the inhibition of aminopeptidase N could play a role in the anti-angiogenic activity of 2,5-dihydroxybenzenesulfonates.