Carbonic Anhydrase Inhibition Potential and Some Bioactivities of the Peripherally Tetrasubstituted Cobalt(II), Titanium(IV), Manganese(III) Phthalocyanines

Background: Peripherally tetrasubstituted cobalt(II), titanium(IV), manganese(III) phthalocyanines carrying redox-active metal centers were previously synthesized. Metallophthalocyanines (MPcs) exhibited the potential to use in medicinal applications due to biological activities, such as antibacterial, antioxidant and enzyme inhibition. Objective: This study's aim was to evaluate the previously synthesized metallophthalocyanines in terms of carbonic anhydrase inhibition, antioxidant, and antimicrobial activities. Methods: Carbonic anhydrase activity was assayed by following esterase activity. The antibacterial activity was tested by the disc diffusion method against eight bacteria. The antioxidant activity was determined by two common methods, 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging and ferric ion (III) reducing/antioxidant power (FRAP) assays. Results: In this study, the inhibition potential of the metallophthallocyanines against carbonic anhydrase (CA) enzyme, which is important for treatments of many disorders, was evaluated. The metallophthalocyanines showed high CA inhibitory activity with IC50 values in the range of 74-317 nM, which was similar or better when compared with the standard CA inhibitors sulfanilamide and acetazolamide. In addition, antibacterial and antioxidant activities were determined. The metallophthallocyanines exhibited moderate antibacterial activity, especially against S. aureus and S. epidermis. The antioxidant activities of the compounds in both tests were quite high, even exceeding the standards Trolox and BHT, with SC50 values of 0.0048-0.0257 and TEAC values of 1143.3- 1543.7 μM, being 2 to 73 fold better activity. Conclusion: In conclusion, all three metallophthalocyanines exhibit excellent carbonic anhydrase and antioxidant potential and deserve further interest for the synthesis of new derivatives.