Pharmacological activities of a propylthiouracil compound structurally modified by coordination with copper(II)

Abstract

For the first time, pharmacological activities for propylthiouracil (actually used as antithyroid drug) were determined. In addition, a new propylthiouracil copper(II) complex ([Cu(PTU)2]2) was synthesized and characterized by FTIR, EPR, UV-visible, and diffuse reflectance spectroscopies including elemental analysis, dissolution profiles, and stability studies. Taking into account the correlation between Graves disease and the formation of reactive oxygen species (ROS) and other free radicals, the ligand and the complex were tested for their antioxidant effects on O2 ·- and OH· radicals. A significant increase in the disruption of OH· radical was observed for PTU and its copper(II) complex, but neither of them have the ability to dismutate the O2 ·- radical. Antimicrobial activities were also determined observing that the complex is very active against Gram-positive bacteria. In addition, the ability of PTU and its complex to inhibit acid and alkaline phosphatases were analyzed. Results showed that PTU had no effect, while the complex behaved as a potent ALP (alkaline phosphatases) inhibitor. Finally, albumin interaction experiments denoted high affinity towards the complex in contrast with PTU with a constant binding value two hundred times higher than the ligand and bearing two binding sites. Based on this study, it has been hypothesized that ([Cu(PTU)2]2 would be a promising candidate for further evaluation as an antioxidant, antimicrobial and phosphatase alkaline inhibitor agent.